[linux-lvm] Mandrake 8.1 and LVM

[linux-lvm] Mandrake 8.1 and LVM

[Sarwer Zafiruddin]

For those Mandrake 8.1 users out there.  Does anyone know if you can setup
the Linux Logical Volume Manager (LVM) during the install?  Ideally, I
would like to put my /,/var,/usr,/tmp filesystems under LVM control, so I
have the ability to expand the filesystems if it every gets full.

Thanks,
Sarwer

--
--------------------------
System Administrator
Rune Information Services
http://www.rune.org
e-mail:  sarwer@rune.org
--------------------------

Re: [linux-lvm] Mandrake 8.1 and LVM

[Luca Berra]

On Thu, Nov 29, 2001 at 09:00:02AM -0500, Sarwer Zafiruddin wrote:
> For those Mandrake 8.1 users out there.  Does anyone know if you can setup
> the Linux Logical Volume Manager (LVM) during the install?  Ideally, I
> would like to put my /,/var,/usr,/tmp filesystems under LVM control, so I
> have the ability to expand the filesystems if it every gets full.

you can setup lvm during install, but you cannot put root over lvm
sorry.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
 /"\
 \ /     ASCII RIBBON CAMPAIGN
  X        AGAINST HTML MAIL
 / \

RE: [linux-lvm] Mandrake 8.1 and LVM

[Steve Wray]

> From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> Behalf Of Luca Berra
> On Thu, Nov 29, 2001 at 09:00:02AM -0500, Sarwer Zafiruddin wrote:
> > For those Mandrake 8.1 users out there.  Does anyone know if you can
setup
> > the Linux Logical Volume Manager (LVM) during the install?  Ideally, I
> > would like to put my /,/var,/usr,/tmp filesystems under LVM control, so
I
> > have the ability to expand the filesystems if it every gets full.
>
> you can setup lvm during install, but you cannot put root over lvm
> sorry.

No don't be sorry!!!

I don't know why people even think of doing that...
Can *anyone* give a good reason (and I don't include
"because its tidier to have everything LVM") for having
root on LVM? Its just begging for trouble; like running
windows XP!

Oh and yes, mandrake 8.1 supports LVM at install; it'll even
detect previous LVM setups and incorporate them into the
install if you want!

My only worry is that Mandrake 8.1 defaults to devfs
and there was a recent message about a problem with devfs and LVM.


>
> L.
>
> --
> Luca Berra -- bluca@comedia.it
>         Communication Media & Services S.r.l.
>  /"\
>  \ /     ASCII RIBBON CAMPAIGN
>   X        AGAINST HTML MAIL
>  / \
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
>
>

Re: [linux-lvm] Mandrake 8.1 and LVM

[Lars Kellogg-Stedman]

> I don't know why people even think of doing that...
> Can *anyone* give a good reason (and I don't include
> "because its tidier to have everything LVM") for having
> root on LVM?


Sure, for the same reason you put *anything* on LVM -- for flexibility 
in storage allocation.  With root on LVM, you can:

(a) create filesystem snapshots for performing consistent backups (or 
for providing a simple 'oops-I-didn't-mean-to-delete-that-just-now' file 
recovery).

(b) dynamically expand the amount of space available to the root partition.

(c) Migrate data to a new set of disks on a live system.

And, of course, it *is* tidier to have everything on LVM :).

On the other hand, there is an element of risk when managing your root 
filesystem with code that hasn't yet stabilized.  It also leads to 
increased complexity.  In particular, you'll probably want to build some 
sort of rescue CD with LVM support in case something goes wrong, since 
most existing rescue tools don't have LVM support.

-- Lars

Re: [linux-lvm] Mandrake 8.1 and LVM

[mitch]

> (b) dynamically expand the amount of space available to the root partition.

Pardon me for being a neophyte here, but what else goes on the root
partition which takes any significant or dynamic amount of space?  Isn't
the root just a place to put all the top level directories, the contents
of which are typically all on another partition anyway?

-- Mitch

RE: [linux-lvm] Mandrake 8.1 and LVM

[Sarwer Zafiruddin]

Expanding / is useful when you need to upgrade the system and the newer OS
needs more space to upgrade.  My primary concern is things under the /var
filesystem, where things grow constantly like logs (which I like to keep
atleast 6months of rotated logs), possibly more space for
/var/spool/mqueue (for mail server that have increase of mail traffic),
and /var/spool/mail (for those hog user who refuse to clean up their INBOX
;-) ).

Sarwer

> > (b) dynamically expand the amount of space available to the root
partition.
> 
> Pardon me for being a neophyte here, but what else goes on the root
> partition which takes any significant or dynamic amount of space?  Isn't
> the root just a place to put all the top level directories, the contents
> of which are typically all on another partition anyway?
> 
> -- Mitch

-- 
--------------------------
System Administrator
Rune Information Services
http://www.rune.org
e-mail:  sarwer@rune.org
--------------------------

RE: [linux-lvm] Mandrake 8.1 and LVM

[Steve Wray]

> From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> Behalf Of mitch@mdmiller.com
> > (b) dynamically expand the amount of space available to the 
> root partition.
> 
> Pardon me for being a neophyte here, but what else goes on the root
> partition which takes any significant or dynamic amount of space?  Isn't
> the root just a place to put all the top level directories, the contents
> of which are typically all on another partition anyway?

Exactly; virtually all the content of the root partition should
be describable as "static/unshareable" which means that it doesn't
need snapshotting in case you accidentally delete something,
or dynamically resizable.

Another of the purposes of the root filesystem is to provide
an island of sanity in a sea of madness when things go wrong;
typically the ideal is to have a system that can easily be
booted into a rescue mode from the root partition only.
In this setup one has "ghost" /usr/*bin et al directories
that are on the root filesystem but get mounted over
when you boot the system for real. These can provide the
tools you need to rescue the system.

Having root LVM just means that if anything goes wrong
with the LVM subsystem then you *need* the system to
be bootable from floppy or CDROM, and that is sometimes
less practical than having root *not* be LVM in the
first place! 
:)
anyhow this is getting away from the topic (which I'm really
interested in); LVM on mandrake 8.1 with devfs...

> 
> -- Mitch
> 
> 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> 
> 

RE: [linux-lvm] Mandrake 8.1 and LVM

[mitch]

Sure ... but doesn't /var typically live on a partition of it's own,
anyway?  Say, is there a HOWTO or other document which describes
partitioning considerations and/or the standard directory structure?
Sorry for all the questions, but I've been brain numbed by a WinTel
world!!

-- Mitch


On Thu, 29 Nov 2001, Sarwer Zafiruddin wrote:

> Expanding / is useful when you need to upgrade the system and the newer OS
> needs more space to upgrade.  My primary concern is things under the /var
> filesystem, where things grow constantly like logs (which I like to keep
> atleast 6months of rotated logs), possibly more space for
> /var/spool/mqueue (for mail server that have increase of mail traffic),
> and /var/spool/mail (for those hog user who refuse to clean up their INBOX
> ;-) ).
>
> Sarwer
>
> > > (b) dynamically expand the amount of space available to the root
> partition.
> >
> > Pardon me for being a neophyte here, but what else goes on the root
> > partition which takes any significant or dynamic amount of space?  Isn't
> > the root just a place to put all the top level directories, the contents
> > of which are typically all on another partition anyway?
> >
> > -- Mitch
>
>

RE: [linux-lvm] Mandrake 8.1 and LVM

[Steve Wray]

> From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> Behalf Of mitch@mdmiller.com
>
> Sure ... but doesn't /var typically live on a partition of it's own,
> anyway?  Say, is there a HOWTO or other document which describes
> partitioning considerations and/or the standard directory structure?
> Sorry for all the questions, but I've been brain numbed by a WinTel
> world!!

Absolutely, var lives by itself because var being filled up
can be part of a denial of service attack... As I recall,
its possible to wind up with an unbootable system if the root
filesystem becomes full. So var and tmp ought to live
on their own partitions or logical volumes.

>
> -- Mitch
>
>
> On Thu, 29 Nov 2001, Sarwer Zafiruddin wrote:
>
> > Expanding / is useful when you need to upgrade the system and
> the newer OS
> > needs more space to upgrade.  My primary concern is things
> under the /var
> > filesystem, where things grow constantly like logs (which I like to keep
> > atleast 6months of rotated logs), possibly more space for
> > /var/spool/mqueue (for mail server that have increase of mail traffic),
> > and /var/spool/mail (for those hog user who refuse to clean up
> their INBOX
> > ;-) ).
> >
> > Sarwer
> >
> > > > (b) dynamically expand the amount of space available to the root
> > partition.
> > >
> > > Pardon me for being a neophyte here, but what else goes on the root
> > > partition which takes any significant or dynamic amount of
> space?  Isn't
> > > the root just a place to put all the top level directories,
> the contents
> > > of which are typically all on another partition anyway?
> > >
> > > -- Mitch
> >
> >
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
>
>

RE: [linux-lvm] Mandrake 8.1 and LVM

[Sarwer Zafiruddin]

IMHO (which shouldn't mean much to anyone), a few Unix platforms out there
do use LVM for their root/OS filesystems, like HP HP-UX and IBM AIX.  My
experience with both are that they are very useful for OS filesystem
issues (especially for failing disks).  The reason LVM works so well in
these platforms is that the kernel, bootup sequences, and installation
media all have tight LVM intergration.  On the other hand I have also seen
piss poor implimentation of LVM with the OS filesystems, like
Solaris/Veritas root encapsulation (when it works...it's good, when it's
broke...prepare for a major headache). I am hopefull as Linux LVM matures,
major distributions will intergrate it as a critical feature of the OS.  That
will also be a major step in making the Linux a more viable OS solution in
the Enterprise.

Sarwer

On Thu, 29 Nov 2001, Steve Wray wrote:

> > From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> > Behalf Of mitch@mdmiller.com
> > > (b) dynamically expand the amount of space available to the 
> > root partition.
> > 
> > Pardon me for being a neophyte here, but what else goes on the root
> > partition which takes any significant or dynamic amount of space?  Isn't
> > the root just a place to put all the top level directories, the contents
> > of which are typically all on another partition anyway?
> 
> Exactly; virtually all the content of the root partition should
> be describable as "static/unshareable" which means that it doesn't
> need snapshotting in case you accidentally delete something,
> or dynamically resizable.
> 
> Another of the purposes of the root filesystem is to provide
> an island of sanity in a sea of madness when things go wrong;
> typically the ideal is to have a system that can easily be
> booted into a rescue mode from the root partition only.
> In this setup one has "ghost" /usr/*bin et al directories
> that are on the root filesystem but get mounted over
> when you boot the system for real. These can provide the
> tools you need to rescue the system.
> 
> Having root LVM just means that if anything goes wrong
> with the LVM subsystem then you *need* the system to
> be bootable from floppy or CDROM, and that is sometimes
> less practical than having root *not* be LVM in the
> first place! 
> :)
> anyhow this is getting away from the topic (which I'm really
> interested in); LVM on mandrake 8.1 with devfs...
> 
> > 
> > -- Mitch
> > 
> > 
> > 
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> > 
> > 
> 
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> 
> 

-- 
--------------------------
System Administrator
Rune Information Services
http://www.rune.org
e-mail:  sarwer@rune.org
--------------------------

RE: [linux-lvm] Mandrake 8.1 and LVM

[Steve Wray]

Sounds to me like Linux is a sort of in-betweeny here!

I assume that its possible to boot HP-UX and AIX machines
from their 'rescue' media and have full and easy access
to the LVM structure?



> From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> Behalf Of Sarwer Zafiruddin
>
> IMHO (which shouldn't mean much to anyone), a few Unix platforms out there
> do use LVM for their root/OS filesystems, like HP HP-UX and IBM AIX.  My
> experience with both are that they are very useful for OS filesystem
> issues (especially for failing disks).  The reason LVM works so well in
> these platforms is that the kernel, bootup sequences, and installation
> media all have tight LVM intergration.  On the other hand I have also seen
> piss poor implimentation of LVM with the OS filesystems, like
> Solaris/Veritas root encapsulation (when it works...it's good, when it's
> broke...prepare for a major headache). I am hopefull as Linux LVM matures,
> major distributions will intergrate it as a critical feature of
> the OS.  That
> will also be a major step in making the Linux a more viable OS solution in
> the Enterprise.
>
> Sarwer
>
> On Thu, 29 Nov 2001, Steve Wray wrote:
>
> > > From: linux-lvm-admin@sistina.com
> [mailto:linux-lvm-admin@sistina.com]On
> > > Behalf Of mitch@mdmiller.com
> > > > (b) dynamically expand the amount of space available to the
> > > root partition.
> > >
> > > Pardon me for being a neophyte here, but what else goes on the root
> > > partition which takes any significant or dynamic amount of
> space?  Isn't
> > > the root just a place to put all the top level directories,
> the contents
> > > of which are typically all on another partition anyway?
> >
> > Exactly; virtually all the content of the root partition should
> > be describable as "static/unshareable" which means that it doesn't
> > need snapshotting in case you accidentally delete something,
> > or dynamically resizable.
> >
> > Another of the purposes of the root filesystem is to provide
> > an island of sanity in a sea of madness when things go wrong;
> > typically the ideal is to have a system that can easily be
> > booted into a rescue mode from the root partition only.
> > In this setup one has "ghost" /usr/*bin et al directories
> > that are on the root filesystem but get mounted over
> > when you boot the system for real. These can provide the
> > tools you need to rescue the system.
> >
> > Having root LVM just means that if anything goes wrong
> > with the LVM subsystem then you *need* the system to
> > be bootable from floppy or CDROM, and that is sometimes
> > less practical than having root *not* be LVM in the
> > first place!
> > :)
> > anyhow this is getting away from the topic (which I'm really
> > interested in); LVM on mandrake 8.1 with devfs...
> >
> > >
> > > -- Mitch
> > >
> > >
> > >
> > > _______________________________________________
> > > linux-lvm mailing list
> > > linux-lvm@sistina.com
> > > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> > >
> > >
> >
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> >
> >
>
> --
> --------------------------
> System Administrator
> Rune Information Services
> http://www.rune.org
> e-mail:  sarwer@rune.org
> --------------------------
>
>
> _______________________________________________
> linux-lvm mailing list
> linux-lvm@sistina.com
> http://lists.sistina.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
>
>

RE: [linux-lvm] Mandrake 8.1 and LVM

[Sarwer Zafiruddin]

I've never had to boot HP-UX in a "rescue" mode, but with AIX, it's mainly
there to mount the root volume group.  I would imagine that HP would be
similar.  I don't think I've ever to to modify the LVM config in rescue
mode.

Sarwer

On Thu, 29 Nov 2001, Steve Wray wrote:

> Sounds to me like Linux is a sort of in-betweeny here!
> 
> I assume that its possible to boot HP-UX and AIX machines
> from their 'rescue' media and have full and easy access
> Sounds to me like Linux is a sort of in-betweeny here!
> 
> I assume that its possible to boot HP-UX and AIX machines
> from their 'rescue' media and have full and easy access
> to the LVM structure?
> 
> 
> 
> > From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> > Behalf Of Sarwer Zafiruddin
> >
> > IMHO (which shouldn't mean much to anyone), a few Unix platforms out
> there
> > do use LVM for their root/OS filesystems, like HP HP-UX and IBM AIX.  My
> > experience with both are that they are very useful for OS filesystem
> > issues (especially for failing disks).  The reason LVM works so well in
> > these platforms is that the kernel, bootup sequences, and installation
> > media all have tight LVM intergration.  On the other hand I have also
> seen
> > piss poor implimentation of LVM with the OS filesystems, like
> > Solaris/Veritas root encapsulation (when it works...it's good, when it's
> > broke...prepare for a major headache). I am hopefull as Linux LVM
> matures,
> > major distributions will intergrate it as a critical feature of
> > the OS.  That
> > will also be a major step in making the Linux a more viable OS solution
> in
> > the Enterprise.
> >
> > Sarwer
> >
> > On Thu, 29 Nov 2001, Steve Wray wrote:
> >
> > > > From: linux-lvm-admin@sistina.com
> > [mailto:linux-lvm-admin@sistina.com]On
> > > > Behalf Of mitch@mdmiller.com
> > > > > (b) dynamically expand the amount of space available to the
> > > > root partition.
> > > >
> > > > Pardon me for being a neophyte here, but what else goes on the root
> > > > partition which takes any significant or dynamic amount of
> > space?  Isn't
> > > > the root just a place to put all the top level directories,
> > the contents
> > > > of which are typically all on another partition anyway?
> > >
> > > Exactly; virtually all the content of the root partition should
> > > be describable as "static/unshareable" which means that it doesn't
> > > need snapshotting in case you accidentally delete something,
> > > or dynamically resizable.
> > >
> > > Another of the purposes of the root filesystem is to provide
> > > an island of sanity in a sea of madness when things go wrong;
> > > typically the ideal is to have a system that can easily be
> > > booted into a rescue mode from the root partition only.
> > > In this setup one has "ghost" /usr/*bin et al directories
> > > that are on the root filesystem but get mounted over
> > > when you boot the system for real. These can provide the
> > > tools you need to rescue the system.
> > >
> > > Having root LVM just means that if anything goes wrong
> > > with the LVM subsystem then you *need* the system to
> > > be bootable from floppy or CDROM, and that is sometimes
> > > less practical than having root *not* be LVM in the
> > > first place!
> > > :)
> > > anyhow this is getting away from the topic (which I'm really
> > > interested in); LVM on mandrake 8.1 with devfs...
> > >
> > > >
> > > > -- Mitch
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > > linux-lvm mailing list
> > > > linux-lvm@sistina.com
> > > > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > > > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> > > >
> > > >
> > >
> > > _______________________________________________
> > > linux-lvm mailing list
> > > linux-lvm@sistina.com
> > > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> > >
> > >
> >
> > --
> > --------------------------
> > System Administrator
> > Rune Information Services
> > http://www.rune.org
> > e-mail:  sarwer@rune.org
> > --------------------------
> >
> >
> > _______________________________________________
> > linux-lvm mailing list
> > linux-lvm@sistina.com
> > http://lists.sistina.com/mailman/listinfo/linux-lvm
> > read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
> >
> >
> 
> 

-- 
--------------------------
System Administrator
Rune Information Services
http://www.rune.org
e-mail:  sarwer@rune.org
--------------------------

Re: [linux-lvm] Mandrake 8.1 and LVM

[Theo Van Dinter]

On Thu, Nov 29, 2001 at 04:10:04PM -0600, mitch@mdmiller.com wrote:
> Sure ... but doesn't /var typically live on a partition of it's own,
> anyway?  Say, is there a HOWTO or other document which describes
> partitioning considerations and/or the standard directory structure?
> Sorry for all the questions, but I've been brain numbed by a WinTel
> world!!

There probably is, but partitioning has always been more art than science so
you'll get a different answer depending on who you talk to and what you're
trying to do.

If you're interested, here's my take on it:

My rule of thumb for disk layout on a server is:
	/boot	- Small, usually 32-128MB, don't run out of space here.
	/	- I put /usr in here since there's no reason not to any
		  longer.  So this will be any size you think is
		  appropriate.	I will usually put anywhere from 4-8GB
		  here, depending on disk size.  These files should be
		  static-ish, no major changed here.  Don't let it hit 100%.
	/var	- As someone's already stated, filling up /var can be a DoS.
		  Also, at least RedHat keeps other things down here, like
		  MySQL/PostgreSQL/etc ...  If you're not going to move this
		  stuff to another area, make /var as big as necessary.  I
		  usually limit /var to log files, give it 1G or so, and move
		  my databases and such to a better partition.
	/tmp	- Yet another possible DoS, don't allow user-writable areas
		  to live on /.  128-512M should be sufficient, it's
		  temporary space after all.

The rest of the disk is split up for any data.  Of that, I would leave
/boot and / as straight partitions and let everything else be LVM-based.
/boot and / are required for booting and if the LVM blows up for some
reason (disk failure, vg won't start, corruption, etc,) you can at least
boot into single user mode and you don't have to worry about non-standard
drivers/rescue disks and the like.

You also get the benefit of LVM for the areas that are more dynamic and may
require shifting over time.

For other non-critical machines (home, personal workstations, etc,) I
tend to just make one big root partition and call it good since I don't
really care about DoS there.  If the box runs out of space, there should be
nothing stored there (it's on the server being backed up, right?,) so I
usually swap hard drives and blow a new OS image on there via
kickstart/jumpstart/your os' favorite automated install system ...

I hope this has been useful to some degree. :)

-- 
Randomly Generated Tagline:
"I am NOT a computer geek! ... I just spend too much time in front of the 
 computer."                  - Theo

Re: [linux-lvm] Mandrake 8.1 and LVM

[Lars Kellogg-Stedman]

mitch@mdmiller.com wrote:


> Pardon me for being a neophyte here, but what else goes on the root
> partition which takes any significant or dynamic amount of space?  Isn't
> the root just a place to put all the top level directories, the contents
> of which are typically all on another partition anyway?


It largely depends on how you set up your system.

For instance, on most systems I set up, I end up having / and /usr on 
the same filesystem, which means that any RPMS I install end up on the 
root partition.  If you start with a fairly small install and later 
decide to add a bunch of flashy office suites, games, or multimedia 
applications, your storage requirements can change drastically.

-- Lars

Re: [linux-lvm] Mandrake 8.1 and LVM

[Chad C. Walstrom]

[-- Attachment #1: Type: text/plain, Size: 2142 bytes --]

On Thu, Nov 29, 2001 at 07:09:20PM -0500, Theo Van Dinter wrote:
> My rule of thumb for disk layout on a server is:
> 	/boot	- Small, usually 32-128MB, don't run out of space here.

Good.

> 	/	- I put /usr in here since there's no reason not to any
> 		  longer.  So this will be any size you think is
> 		  appropriate.	I will usually put anywhere from 4-8GB
> 		  here, depending on disk size.  These files should be
> 		  static-ish, no major changed here.  Don't let it hit 100%.

Reason #1:  Mount /usr as read-only.  There is only one reason why you
should mount /usr read/write: to install software.  Upon completion of
this one task, remount the drive as read-only.  Lock it down with kernel
capabilities tools, and be done with it.  [apt-get has a nice way to
auto-remount the drive in apt.conf(5) when installing/upgrading
software.]

That being said, I suppose there's not a whole lot holding you back from
mounting "/" as read-only, either.  Perhaps /etc/mtab would be an
annoyance, but if you symbolically link it to /proc/mounts, you could
fake it.

Reason #2:  With LVM, you don't have to worry about exceeding the
standard "allowed" harddrive partitions.  So, create logical volumes to
your heart's (*ahem*) extent.  With filesystem and logical volume
resizing, the flexibility and convenience outweight the small
"overhead."

Reason #3: It's just plain strange to have / share space with /usr.

Reason #4: For someone new to Linux, LVM provides you with the
opportunity to correct a mistake without having to reinstall your system
because you'd prefer a different harddrive partition layout.

OK, so that got into some more generic reasons to use LVM rather than to
give guideance on how/what/when/where/why to patition a certain way.
Experiment, have fun.  With LVM, you can afford to play in order to find
that "perfect" balance of partitioning and practicality.

-- 
Chad Walstrom <chewie@wookimus.net>                 | a.k.a. ^chewie
http://www.wookimus.net/                            | s.k.a. gunnarr
Key fingerprint = B4AB D627 9CBD 687E 7A31  1950 0CC7 0B18 206C 5AFD


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Re: [linux-lvm] Mandrake 8.1 and LVM

[Luca Berra]

On Fri, Nov 30, 2001 at 10:05:18AM +1300, Steve Wray wrote:
> > you can setup lvm during install, but you cannot put root over lvm
> > sorry.
> 
> No don't be sorry!!!
> 
> I don't know why people even think of doing that...
well i do
> Can *anyone* give a good reason (and I don't include
> "because its tidier to have everything LVM") for having
> root on LVM? Its just begging for trouble; like running
> windows XP!
i have been running root lvm for about 1 year on my main system
which has a respectable uptime.
i am in the process of changing it to a new system, which will run mandrake
8.1 and will have root lvm as the previous one.

it is tidier, more flexible, and since linux distribution makers default to
trowing every piece of junk in /lib, and provide dynamycally linked executables
in /sbin, i have been bitten once too many whith a small root.

what i believe is that boot loaders should be able to read files off LVM volumes (provided they are
contigous), like patched lilo does, and that we should all live without the idiotic partition
tables, heck even microshaft groked this!

wherever root is you better have a way of booting into your system if root is corrupted.

> My only worry is that Mandrake 8.1 defaults to devfs
> and there was a recent message about a problem with devfs and LVM.
i have both devfs and lvm, there are known bugs in the lvm tools regarding devfs, but none critical
someone (me?) will fix these sooner or later.

what i'll do next is fixing mkinitrd to understand lvm root.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] Mandrake 8.1 and LVM

[Luca Berra]

On Fri, Nov 30, 2001 at 11:45:24AM +1300, Steve Wray wrote:
> Sounds to me like Linux is a sort of in-betweeny here!
> 
> I assume that its possible to boot HP-UX and AIX machines
> from their 'rescue' media and have full and easy access
> to the LVM structure?

HP does have 2 methods

a lvm maint mode where lvm is not activated and root is statically mapped in
kernel (there is some long mails between me and someone else in the archives
discussing it in depth).

an install/rescue media that can be used to do lvm mainteinance

with mandrake rescue media you should be able to do lvm mainteinance (but
mandrake rescue media has other bugs....)

L.


-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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RE: [linux-lvm] Mandrake 8.1 and LVM

[Steve Wray]

> From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> Behalf Of Chad C. Walstrom
>
> On Thu, Nov 29, 2001 at 07:09:20PM -0500, Theo Van Dinter wrote:
> > My rule of thumb for disk layout on a server is:
> > 	/boot	- Small, usually 32-128MB, don't run out of space here.
>
> Good.
>
> > 	/	- I put /usr in here since there's no reason not to any
> > 		  longer.  So this will be any size you think is
> > 		  appropriate.	I will usually put anywhere from 4-8GB
> > 		  here, depending on disk size.  These files should be
> > 		  static-ish, no major changed here.  Don't let it hit 100%.
>
> Reason #1:  Mount /usr as read-only.  There is only one reason why you

ONLY if you also have /usr/share (for one, there may be others) on writeable
partitions!!!


> That being said, I suppose there's not a whole lot holding you back from
> mounting "/" as read-only, either.  Perhaps /etc/mtab would be an
> annoyance, but if you symbolically link it to /proc/mounts, you could
> fake it.

surely theres more than that in /etc that needs to be writeable?
hmmmm doesn't /lib/modules/<something to do with module dependencise>
need to be writeable too?

Re: [linux-lvm] Mandrake 8.1 and LVM

[Theo Van Dinter]

[-- Attachment #1: Type: text/plain, Size: 3498 bytes --]

On Fri, Nov 30, 2001 at 02:01:18AM -0600, Chad C. Walstrom wrote:
> Reason #1:  Mount /usr as read-only.  There is only one reason why you
> should mount /usr read/write: to install software.  Upon completion of
> this one task, remount the drive as read-only.  Lock it down with kernel
> capabilities tools, and be done with it.  [apt-get has a nice way to
> auto-remount the drive in apt.conf(5) when installing/upgrading
> software.]

That depends on how paranoid you are regarding security.  My feeling
is that if someone can get enough access to write to pieces of / and
/usr that they shouldn't, they will likely have enough access to damage
the system anyway (fdisk/dd/lilo/grub/etc.)  So you really only protect
yourself from accidental damage (which shouldn't happen on a properly
configured box) and attackers who aren't creative.  ;)

I don't know much about the kernel capabilities facility, but if you
can mount the partition read-write to install apps without rebooting,
you haven't bought yourself anything.  If you can't (I assume that's
the benefit,) then you'll have to take a downtime whenever you want to
upgrade something which may or may not be a problem in your environment.

The "no reason" bit was more aimed at the carry-over from OSes like
SunOS where it was suggested (although I forget why at the moment) that
/ and /usr be on different partitions.  I think it was something about
partition location on disk, but that's another discussion.  :)

> Reason #2:  With LVM, you don't have to worry about exceeding the
> standard "allowed" harddrive partitions.  So, create logical volumes to
> your heart's (*ahem*) extent.  With filesystem and logical volume
> resizing, the flexibility and convenience outweight the small
> "overhead."

You're right about the exceeding available space, but /usr in LVM also
means that given a problem with LVM, you're unlikely to be able to get
your box to single-user mode.  Even if you do (I haven't tested this),
you're going to find a very limited environment without /usr.

With / on LVM, you're definately unable to boot if LVM has problems.

This is a problem I've seen a number of times on HPUX.  The OS disk is
under LVM in vg00.  People want more disk space and so they add another
disk to vg00 and go make new logical volumes (or worse, extend OS lvs.)
It's not a problem until this new disk fails (or isn't powered on before
bootup, or ...)  Then the volume group can't be started and the machine
won't boot.  If you've extended a core OS lv (/, /usr, /var, etc,) you've
just won yourself a restore/reinstall.  All that while having the main OS
disk still running perfectly.

At least with / and /usr outside of LVM, it'd likely be easier to recover
from the failure.

> Reason #3: It's just plain strange to have / share space with /usr.

Matter of opinion. :)

> Reason #4: For someone new to Linux, LVM provides you with the
> opportunity to correct a mistake without having to reinstall your system
> because you'd prefer a different harddrive partition layout.

True, but it also adds more complexity to setting up and maintaining the
system.

> Experiment, have fun.  With LVM, you can afford to play in order to find
> that "perfect" balance of partitioning and practicality.

:)

-- 
Randomly Generated Tagline:
"UNIX was not designed to stop you from doing stupid things, because
 that would also stop you from doing clever things." - Larry Wall

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Re: [linux-lvm] Mandrake 8.1 and LVM

[Luca Berra]

On Fri, Nov 30, 2001 at 11:49:12AM -0500, Theo Van Dinter wrote:
> On Fri, Nov 30, 2001 at 02:01:18AM -0600, Chad C. Walstrom wrote:
> With / on LVM, you're definately unable to boot if LVM has problems.
with / on ext2 you're definately unable to boot if ext2 has problems.

> This is a problem I've seen a number of times on HPUX.  The OS disk is
you cannot extend / under HP-UX (they don't have initrd)
besides i don't see the difference with someone having / un one disk
and /usr on another without LVM.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] Mandrake 8.1 and LVM

[svetljo]

>
>
>>With / on LVM, you're definately unable to boot if LVM has problems.
>>
>with / on ext2 you're definately unable to boot if ext2 has problems.
>
sorry , but you can not compare the PB's
it's not about the FS , but the device access

>>This is a problem I've seen a number of times on HPUX.  The OS disk is
>>
>you cannot extend / under HP-UX (they don't have initrd)
>
initrd ?
isn't that smth special for linux ?
the next version of LVM should work without initrd and EVMS works 
without initrd
the kernel should be able to activate the devices without additional 
binaries

>besides i don't see the difference with someone having / un one disk
>and /usr on another without LVM.
>
isn't it common for all *nix OSes that they have a small / with only the 
very essential libraries , binaries and conf's
and everything other goes to /usr 

Re: [linux-lvm] Mandrake 8.1 and LVM

[Chad C. Walstrom]

[-- Attachment #1: Type: text/plain, Size: 1782 bytes --]

On Fri, Nov 30, 2001 at 09:41:21PM +1300, Steve Wray wrote:
> > Reason #1:  Mount /usr as read-only.  There is only one reason why you
> 
> ONLY if you also have /usr/share (for one, there may be others) on writeable
> partitions!!!

Why would you want/need to have /usr/share writeable?  FHS 2.2 states:

        4.11  /usr/share : Architecture-independent data

        4.11.1  Purpose

        The /usr/share hierarchy is for all read-only architecture
        independent data files. [25]

        This hierarchy is intended to be shareable among all architecture
        platforms of a given OS; thus, for example, a site with i386,
        Alpha, and PPC platforms might maintain a single /usr/share
        directory that is centrally-mounted.  Note, however, that
        /usr/share is generally not intended to be shared by different
        OSes or by different releases of the same OS.

        Any program or package which contains or requires data that
        doesn't need to be modified should store that data in /usr/share
        (or /usr/local/share, if installed locally).  It is recommended
        that a subdirectory be used in /usr/share for this purpose.

        Game data stored in /usr/share/games must be purely static data.
        Any modifiable files, such as score files, game play logs, and so
        forth, should be placed in /var/games.

        ...

        Footnote: 
        25.  Much of this data originally lived in /usr  (man,  doc)  or
        /usr/lib (dict, terminfo, zoneinfo).

-- 
Chad Walstrom <chewie@wookimus.net>                 | a.k.a. ^chewie
http://www.wookimus.net/                            | s.k.a. gunnarr
Get my public key, ICQ#, etc. $(mailx -s 'get info' chewie@wookimus.net)

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Re: [linux-lvm] Mandrake 8.1 and LVM

[mitch]

> Why would you want/need to have /usr/share writeable?  FHS 2.2 states:

Where do I find this document?

-- Mitch

Re: [linux-lvm] Mandrake 8.1 and LVM

[Petro]

On Fri, Nov 30, 2001 at 12:20:15PM -0800, Chad C. Walstrom wrote:
> On Fri, Nov 30, 2001 at 09:41:21PM +1300, Steve Wray wrote:
> > > Reason #1:  Mount /usr as read-only.  There is only one reason why
> you
> > ONLY if you also have /usr/share (for one, there may be others) on
> writeable
> > partitions!!!
> Why would you want/need to have /usr/share writeable?  FHS 2.2 states:
>         4.11  /usr/share : Architecture-independent data
>         4.11.1  Purpose
>         The /usr/share hierarchy is for all read-only architecture
>         independent data files. [25]
    
    So you can install software that puts stuff in /usr/share/man and
    /usr/share/doc?  


-- 
Share and Enjoy. 

RE: [linux-lvm] Mandrake 8.1 and LVM

[Steve Wray]

> From: linux-lvm-admin@sistina.com [mailto:linux-lvm-admin@sistina.com]On
> Behalf Of Chad C. Walstrom
> Sent: Saturday, 1 December 2001 09:20
> To: linux-lvm@sistina.com
> Subject: Re: [linux-lvm] Mandrake 8.1 and LVM
>
>
> On Fri, Nov 30, 2001 at 09:41:21PM +1300, Steve Wray wrote:
> > > Reason #1:  Mount /usr as read-only.  There is only one reason why you
> >
> > ONLY if you also have /usr/share (for one, there may be others)
> on writeable
> > partitions!!!
>
> Why would you want/need to have /usr/share writeable?  FHS 2.2 states:

On redhat and mandrake for two, there are things in /usr/share that
are written to at runtime.
One I can think of right off the bat is cddb information.


[snip]
>         Game data stored in /usr/share/games must be purely static data.
>         Any modifiable files, such as score files, game play logs, and so
>         forth, should be placed in /var/games.

Since when was any distribution 100% compliant with the standards?
:)

Re: [linux-lvm] Mandrake 8.1 and LVM

[Chad C. Walstrom]

[-- Attachment #1: Type: text/plain, Size: 1437 bytes --]

On Sat, Dec 01, 2001 at 11:05:22AM +1300, Steve Wray wrote:
> > Why would you want/need to have /usr/share writeable?  FHS 2.2 states:
> 
> On redhat and mandrake for two, there are things in /usr/share that
> are written to at runtime.  One I can think of right off the bat is
> cddb information.

Ah, yes.  The critical system applications, bat and cddb.  No reason to
configure or recompile (if they, *gasp* have hardcoded paths in their
executables) these to actually store their caches under a more resonable
location.  Perhaps the partition that is most often dedicated to
variable data generated by applications during their runtime...  /var.

> [snip]
> >         Game data stored in /usr/share/games must be purely static data.
> >         Any modifiable files, such as score files, game play logs, and so
> >         forth, should be placed in /var/games.
> 
> Since when was any distribution 100% compliant with the standards?

Especially if you're talking about Red Hat and Mandrake. ;-)

Seriously, I think it is perfectly reasonable to be a nazi with your
filesystem.  But this is SO way off topic right now, I'm going to
refrain from further comment.

Have a great weekend!

-- 
Chad Walstrom <chewie@wookimus.net>                 | a.k.a. ^chewie
http://www.wookimus.net/                            | s.k.a. gunnarr
Get my public key, ICQ#, etc. $(mailx -s 'get info' chewie@wookimus.net)

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Re: [linux-lvm] Mandrake 8.1 and LVM

[Chad C. Walstrom]

[-- Attachment #1: Type: text/plain, Size: 1062 bytes --]

On Fri, Nov 30, 2001 at 02:02:21PM -0800, Petro wrote:
> So you can install software that puts stuff in /usr/share/man and
> /usr/share/doc?  

What's to stop you from installing software if you have mounted your
partition as read only?  It only forces you to do an extra step.

    bash# mount -o remount,rw /usr
    bash# # install your software
    bash# sync; mount -o remount,ro /usr

If the software is "putting stuff", a.k.a. creating variable data, it
belongs in a /var location.  i.e. /var/cache/man/...

Remember, the object of FHS is to provide people the ability to NFS
share their /usr partition.  If you have applications changing the data
on a number of machines to these directories, you're going to regret
your filesystem management decisions.  /var is for locally generated
data created by applications.

-- 
Chad Walstrom <chewie@wookimus.net>                 | a.k.a. ^chewie
http://www.wookimus.net/                            | s.k.a. gunnarr
Get my public key, ICQ#, etc. $(mailx -s 'get info' chewie@wookimus.net)

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Re: [linux-lvm] Mandrake 8.1 and LVM

[Chad C. Walstrom]

[-- Attachment #1: Type: text/plain, Size: 701 bytes --]

On Fri, Nov 30, 2001 at 04:02:16PM -0600, mitch@mdmiller.com wrote:
> > Why would you want/need to have /usr/share writeable?  FHS 2.2 states:
> 
> Where do I find this document?

As any good google.com crack-baby would know:

    http://www.google.com/search?q=FHS+2.2+Linux

Turns up these helpful links:

    http://www.pathname.com/fhs/
    http://www.opengroup.org/testing/lsb-fhs/

OK, now back to your regularily scheduled LVM-ness.  Sorry for the
tangent.

-- 
Chad Walstrom <chewie@wookimus.net>                 | a.k.a. ^chewie
http://www.wookimus.net/                            | s.k.a. gunnarr
Get my public key, ICQ#, etc. $(mailx -s 'get info' chewie@wookimus.net)

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Re: [linux-lvm] Mandrake 8.1 and LVM

[mitch]

> > Where do I find this document?
>
> As any good google.com crack-baby would know:
>
>     http://www.google.com/search?q=FHS+2.2+Linux
>
> Turns up these helpful links:
>
>     http://www.pathname.com/fhs/
>     http://www.opengroup.org/testing/lsb-fhs/
>
> OK, now back to your regularily scheduled LVM-ness.  Sorry for the
> tangent.
>
>
Duh ... thanks.  Didn't mean to make someone else do the work ... guess I
just lost my head there for a moment.

-- Mitch

Re: [linux-lvm] Mandrake 8.1 and LVM

[Brian J. Murrell]

On Fri, Nov 30, 2001 at 09:36:56AM +0100, Luca Berra wrote:
> 
> with mandrake rescue media you should be able to do lvm mainteinance (but
> mandrake rescue media has other bugs....)

Beware.  I don't think Mandrake install (is that what you are
referencing as rescue) media has the tools.  I put some lvmtools in my
/boot partition which is not LVM.  I can then mount that from the
install CD (in rescue mode) and get LVM going again in the case of
booting problem.

b.

-- 
Brian J. Murrell

Re: [linux-lvm] Mandrake 8.1 and LVM

[Wolfgang Weisselberg]

Hi, Theo!

Theo Van Dinter (felicity@kluge.net) wrote 60 lines:

> My rule of thumb for disk layout on a server is:
> 	/boot	- Small, usually 32-128MB, don't run out of space here.

You can also do a combined / and /boot.  Give it enough space
and move everything where non-related changes happen away
from it.  (128 to 256 MB should outlast your HD.)  Non-LVM.

> 	/	- I put /usr in here since there's no reason not to any

Personally I feel /usr really wants a separate partition.
You also may want partitions for /usr/src (if you have lots of
compiling/source code for the whole machine), and /usr/local
(if you use more than a few programs which are not on your
distribution).  Sub-partitions are possible, depending on usage.
Long live LVM.

> 	/var	- As someone's already stated, filling up /var can be a DoS.

If you have a news spool, put it on a separate partition --
it's just too different from size and lifetime compared to
/var.  Unless you have a non-file/hardlink-based news system.
And then still move it out of the way.

If you have a WWW cache, that one might want a separate
partition as well -- and usually there's no need to backup
that cache.


> 	/tmp	- Yet another possible DoS, don't allow user-writable areas
> 		  to live on /.  128-512M should be sufficient, it's
> 		  temporary space after all.

More -- especially with quotas.  Sometimes people have to
download CD-Rom Images (e.g. .iso) and might be unable to put
them into /home.

Speaking of it -- /home probably wants a partition, too; and
regular backups.

-Wolfgang

Re: [linux-lvm] Mandrake 8.1 and LVM

[Brian J. Murrell]

On Fri, Nov 30, 2001 at 09:30:08AM +0100, Luca Berra wrote:
> 
> what i'll do next is fixing mkinitrd to understand lvm root.

I have the current Mandrake Cooker mkinitrd RPM patched to know how to
do lvm root.  I actually have also made (almost) all of the changes to
the Mandrake installer to install on an lvm root.  I got stumped by
one bit of perl (my perl5 sucks) that was causing the device to be
determined as /dev/dev/volgroup/root when it came time to doing the
LILO/Grub configuration.

I have not gotten back to it yet because my perl5 is no better than it
was when I got stumped.  I do have a big fat per5 book now though.
:-)

b.

-- 
Brian J. Murrell

Re: [linux-lvm] Mandrake 8.1 and LVM

[Luca Berra]

On Fri, Nov 30, 2001 at 07:03:00PM +0100, svetljo wrote:
> >>With / on LVM, you're definately unable to boot if LVM has problems.
> >>
> >with / on ext2 you're definately unable to boot if ext2 has problems.
> >
> sorry , but you can not compare the PB's
> it's not about the FS , but the device access

why not? see below

> >>This is a problem I've seen a number of times on HPUX.  The OS disk is
> >>
> >you cannot extend / under HP-UX (they don't have initrd)
> >
> initrd ?
> isn't that smth special for linux ?
yes, i was *joking*, what i meant was that lvm information for
booting is fed statically to the kernel.

> the next version of LVM should work without initrd and EVMS works 
> without initrd
> the kernel should be able to activate the devices without additional 
> binaries
linux also has _initfunc, which should free the kernel from bloat of
driver initialization code (eg kernelspace implementations of
vgscan/vgchange)
> >besides i don't see the difference with someone having / un one disk
> >and /usr on another without LVM.
> >
> isn't it common for all *nix OSes that they have a small / with only the 
> very essential libraries , binaries and conf's
> and everything other goes to /usr 
please I'd be thankful if ppl did read emails in the thread before replying
I was responding to Theo's claims, who said that if a luser extends /
over two disks he duubles the chance of failure. I was saying that lusers
has many ways of of shooting themselves in the feet.

my point is that there is no reason saying that root lvm is dangerous
and should be avoided. i have been using it for almost an year, and
i consider it as stable as root on an extended pc partition.

L.

-- 
Luca Berra -- bluca@comedia.it
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[linux-lvm] Mandrake 8.1 and LVM

[Luca Berra]

getting back in thread :)
i have uploaded 1.0.1 rpm and spec file for mandrake at:

http://www.comedia.it/bluca/lvm/lvm-1.0.1-1mdk.src.rpm
and
http://www.comedia.it/bluca/lvm/lvm.spec

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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Re: [linux-lvm] Mandrake 8.1 and LVM

[galia]

> getting back in thread :)
> i have uploaded 1.0.1 rpm and spec file for mandrake at:
> 
> http://www.comedia.it/bluca/lvm/lvm-1.0.1-1mdk.src.rpm
> and
> http://www.comedia.it/bluca/lvm/lvm.spec
:)
why there is no cc to cooker@mandrake-linux.com 

:)

Re: [linux-lvm] Mandrake 8.1 and LVM

[Mark van Walraven]

On Thu, Nov 29, 2001 at 03:50:54PM -0600, mitch@mdmiller.com wrote:
> Pardon me for being a neophyte here, but what else goes on the root
> partition which takes any significant or dynamic amount of space?  Isn't
> the root just a place to put all the top level directories, the contents
> of which are typically all on another partition anyway?

/bin, /sbin and /lib can get quite large; /etc can also get a little fat.
I like to keep them (and /boot) on the root partition, I guess because
they are all critical for booting and seldom altered.

Regards,

Mark.