RE: [linux-lvm] lvm/fs issue

RE: [linux-lvm] lvm/fs issue

[Rosenstrauch, David]

> I'm not sure about your error, but I would merge sda[6789] 
> into a single
> partition.  Splitting a disk and then putting it back together in
> software just adds an unnecessary load to your system (only 
> one Physcial
> Volume per disk).  In other words, sda6 should go from 16845.016 to
> 38154.000.  Getting there may be a challenge, though ;-)


Well, splitting and putting back together is not what I'm doing, although it
might look like that.

Although I currently have only 1 logical volume, and all my PV's are currently
a part of it, that's not necessarily how things will always be.  I
intentionally partitioned most of my disk into ~2GB chunks like this, so that
I can have a pool of 2GB PV's which I can throw at whichever LV needs it, and
thereby rid myself of future space constraint issues I've run into in the past
with traditional partitioning.


> Taking a stab at your problem, I would first look to see if you've
> exclude sda3 from LVM.  I am guessing that you haven't, and 
> that LVM is
> trying to read a PV id off sda3.


Yeah, that seems to be the general consensus.  Looks like LVM was until
recently either ignoring extended partitions or not reporting error messages
on them, which is why I only started to see this recently.

Thanks,

DR

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Re: [linux-lvm] lvm/fs issue

[Kevin P. Fleming]

Rosenstrauch, David wrote:

> Although I currently have only 1 logical volume, and all my PV's are currently
> a part of it, that's not necessarily how things will always be.  I
> intentionally partitioned most of my disk into ~2GB chunks like this, so that
> I can have a pool of 2GB PV's which I can throw at whichever LV needs it, and
> thereby rid myself of future space constraint issues I've run into in the past
> with traditional partitioning.

But that's the whole point of LVM in the first place!

If you make a single PV, with a VG including it, you can carve it up and 
re-carve it up however you like, for whatever LVs you have or create in 
the future. You can even _shrink_ LVs and make the space available to 
other LVs, which you cannot do with partitions.

RE: [linux-lvm] lvm/fs issue

[Rosenstrauch, David]

> -----Original Message-----
> From: linux-lvm-bounces@redhat.com
> [mailto:linux-lvm-bounces@redhat.com]On Behalf Of Kevin P. Fleming
> Sent: Tuesday, December 21, 2004 12:11 PM
> To: LVM general discussion and development
> Subject: Re: [linux-lvm] lvm/fs issue
> 
> 
> Rosenstrauch, David wrote:
> 
> > Although I currently have only 1 logical volume, and all my 
> PV's are currently
> > a part of it, that's not necessarily how things will always be.  I
> > intentionally partitioned most of my disk into ~2GB chunks 
> like this, so that
> > I can have a pool of 2GB PV's which I can throw at 
> whichever LV needs it, and
> > thereby rid myself of future space constraint issues I've 
> run into in the past
> > with traditional partitioning.
> 
> But that's the whole point of LVM in the first place!
> 
> If you make a single PV, with a VG including it, you can 
> carve it up and 
> re-carve it up however you like, for whatever LVs you have or 
> create in 
> the future. You can even _shrink_ LVs and make the space available to 
> other LVs, which you cannot do with partitions.


Hmm.  I guess I didn't quite understand that then.  I knew that you could have
a LV that spans multiple PV's (which is what I figured was the whole point of
LVM - you could just keep throwing more PV's at an LV as your space needs
grew), but I didn't know that you could have a PV that gets split across
multiple LV's.  I guess I just assumed (don't know why) that each PV had to be
dedicated to 1 and only 1 LV.

Thanks for setting me straight then.  No real big problem for me the way I
have it now, though.  I guess I might suffer a little bit performance-wise,
but this is my desktop development machine, not a server, so no huge loss.
Good to have my facts straight for the future, though.

Thanks again,

DR

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RE: [linux-lvm] lvm/fs issue

[Rosenstrauch, David]

> On Tue, Dec 21, 2004 at 03:19:49PM -0000, Rosenstrauch, David wrote:
> >   /dev/sda3: read failed after 0 of 2048 at 0: Input/output error
> 
> It's harmless - safe to ignore.
> 
> Which version of LVM2 and what architecture?  
> 
> 2.00.30 started displaying detailed errors like this so we 
> can find out 
> about them and fix them; older versions silently ignored them.
> 
> Alasdair


v2.00.31 (as of a week ago).  I'm using kernel 2.6.9 on an Intel Pentium 4
(with Hyperthreading).

Thanks!

DR

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Re: [linux-lvm] lvm/fs issue

[Alasdair G Kergon]

On Tue, Dec 21, 2004 at 03:48:41PM -0000, Rosenstrauch, David wrote:
> v2.00.31 (as of a week ago).  I'm using kernel 2.6.9 on an Intel Pentium 4
> (with Hyperthreading).
 
Curious that I've not been seeing that error (with 2.6.10-something).
Perhaps affected by the end-of-device direct-io patch.

Anyway, I've just checked a fix into CVS.

Alasdair
-- 
agk@redhat.com

RE: [linux-lvm] lvm/fs issue

[Rosenstrauch, David]

> On Tue, Dec 21, 2004 at 03:19:49PM -0000, Rosenstrauch, David wrote:
> > Hi.  Having an odd problem with lvm and/or my file system.  
> Can anyone offer
> > any ideas what might be wrong?
> > 
> 
> The data is fine - it's LVM trying to read the extended 
> partition (which
> contains no data).
> 
> Simply exclude /dev/sda3 using a filter in /etc/lvm/lvm.conf.
> 
> -- 
> 
> patrick


OK - that's easy enough to do.

I was just about to write  "Not sure why I just started seeing this only
recently, though".  But then I realized that my distro just upgraded to LVM
2.00.31 last Monday (12/13).  As I shutdown every Friday and reboot every
Monday, that explains why yesterday was the first time I would have seen this.

Thanks for the help!

DR

P.S.  LVM has been working great for me.  Kudos and thanks to everyone who's
worked hard to provide such a great tool to the community!

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[linux-lvm] lvm/fs issue

[Rosenstrauch, David]

Hi.  Having an odd problem with lvm and/or my file system.  Can anyone offer
any ideas what might be wrong?

Drive is set up as follows:

(parted) print
Disk geometry for /dev/sda: 0.000-38154.375 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.016    244.000  primary   reiserfs    boot
2        244.000   2197.000  primary   linux-swap
3       2197.000  38154.000  extended
5       2197.016  16845.000  logical   reiserfs
6      16845.016  21728.000  logical
7      21728.016  26611.000  logical
8      26611.016  31494.000  logical
9      31494.016  38154.000  logical


/dev/sda3 is an extended partition, with /dev/sda5 through 9 under it.
/dev/sda5 is a standard reiser partition (mounted at /), and /dev/sda6 through
9 make up a logical volume /dev/lvgroup1/lvshare (also using reiserfs) which
gets mounted at /usr/local/share.

All is basically going well, but recently I started to see some odd messages
popping up during various lvm calls:
  /dev/sda3: read failed after 0 of 2048 at 0: Input/output error

This happens at boot time, when my distro does some LVM initialization, as
well as when I issue lvm commands from the command line:

[root@wnyc190562661 ~]# lvm pvs
  /dev/sda3: read failed after 0 of 2048 at 0: Input/output error
  PV         VG       Fmt  Attr PSize PFree
  /dev/sda6  lvgroup1 lvm2 a-   4.77G    0
  /dev/sda7  lvgroup1 lvm2 a-   4.77G    0
  /dev/sda8  lvgroup1 lvm2 a-   4.77G 2.30G
  /dev/sda9  lvgroup1 lvm2 a-   6.50G 6.50G


I'm a bit stumped on what the problem could be or how to go about fixing it.
Since the message occurs during LVM commands (and since I don't see a similar
error when the non-LVM /dev/sda5 gets mounted), I have to assume that the
problem is something wrong on one of my PV partitions /dev/sda6 through 9.
(Doesn't seem like there could be something wrong with /dev/sda3, since
there's no real data held there.)  However, when I umounted /usr/local/share
and did a fsck on the logical volume, nothing showed up.


I'm obviously very concerned, since input/output errors make me wonder whether
my disk is in danger of dying.  On the other hand, though, other than this odd
error message, everything seems to be working fine.  Anyone ever seen anything
like this before?  Is this even an LVM problem?  Any ideas on how to go about
addressing it?  I'm really not sure what else to try at this point.

TIA,

DR


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Re: [linux-lvm] lvm/fs issue

[Patrick Caulfield]

On Tue, Dec 21, 2004 at 03:19:49PM -0000, Rosenstrauch, David wrote:
> Hi.  Having an odd problem with lvm and/or my file system.  Can anyone offer
> any ideas what might be wrong?
> 

The data is fine - it's LVM trying to read the extended partition (which
contains no data).

Simply exclude /dev/sda3 using a filter in /etc/lvm/lvm.conf.

-- 

patrick

Re: [linux-lvm] lvm/fs issue

[David Johnston]

On Tue, 2004-12-21 at 10:19, Rosenstrauch, David wrote:
> Hi.  Having an odd problem with lvm and/or my file system.  Can anyone offer
> any ideas what might be wrong?
> 
> Drive is set up as follows:
> 
> (parted) print
> Disk geometry for /dev/sda: 0.000-38154.375 megabytes
> Disk label type: msdos
> Minor    Start       End     Type      Filesystem  Flags
> 1          0.016    244.000  primary   reiserfs    boot
> 2        244.000   2197.000  primary   linux-swap
> 3       2197.000  38154.000  extended
> 5       2197.016  16845.000  logical   reiserfs
> 6      16845.016  21728.000  logical
> 7      21728.016  26611.000  logical
> 8      26611.016  31494.000  logical
> 9      31494.016  38154.000  logical
> 
> 
> /dev/sda3 is an extended partition, with /dev/sda5 through 9 under it.
> /dev/sda5 is a standard reiser partition (mounted at /), and /dev/sda6 through
> 9 make up a logical volume /dev/lvgroup1/lvshare (also using reiserfs) which
> gets mounted at /usr/local/share.

I'm not sure about your error, but I would merge sda[6789] into a single
partition.  Splitting a disk and then putting it back together in
software just adds an unnecessary load to your system (only one Physcial
Volume per disk).  In other words, sda6 should go from 16845.016 to
38154.000.  Getting there may be a challenge, though ;-)

Taking a stab at your problem, I would first look to see if you've
exclude sda3 from LVM.  I am guessing that you haven't, and that LVM is
trying to read a PV id off sda3.
-- 
David Johnston <david@littlebald.com>
Little Bald Consulting, LLC

Re: [linux-lvm] lvm/fs issue

[Alasdair G Kergon]

On Tue, Dec 21, 2004 at 03:19:49PM -0000, Rosenstrauch, David wrote:
>   /dev/sda3: read failed after 0 of 2048 at 0: Input/output error

It's harmless - safe to ignore.

Which version of LVM2 and what architecture?  

2.00.30 started displaying detailed errors like this so we can find out 
about them and fix them; older versions silently ignored them.

Alasdair
-- 
agk@redhat.com