md: can not impport hdb1, has active inodes!

md: can not impport hdb1, has active inodes!

[Chris Evans]

Debian stable 2.4.19 kernel with RAID1 compiled in, VIA EPIA CL1000 
motherboard, 2 Maxtor DiamondMax 9 7200rpm 80Gb drives as /dev/hdb 
and /dev/hdc from onboard controller.

I've followed the guide at:
http://www.cs.montana.edu/faq/faqw.admin.py?query=Convert+Root+System+
to+Software+Raid&querytype=simple&casefold=yes&req=search

which had turned up on a debian list search to try to set up the 
RAID1 mirror of the boot/root drive.  I installed to /dev/hdb1 
(/dev/hda is the CDROM and perhaps I should have changed that first). 

Loaded 2.2.20, got 2.4.19 sources, compiled RAID1 support into the 
kernel (still can't get rid of one complaint about a missing 
character set module but don't think that's causing any real 
problems), made the identical /dev/hdc1 into a somewhat smaller linux 

autodetect RAID format partition, mounted it as 2nd drive in a RAID1 
drive using:
  mdadm --create /dev/md0 --level=1 --raid-disks=2 missing /dev/hdc1
which worked fine, mkfs -t ext3 /dev/hdc1, mount it to /mnt1, 
cp -ax / /mnt, tweak /etc/fstab ... /dev/md0 mounts fine, tweak lilo 
conf to boot from /dev/md0, reboot -- fine, finally come to add 
/dev/hdb1 into the array after resetting the partition type to 
autodetect RAID ... 

.. no go, system complains that /dev/hdb1 is mounted or that an inode 

is active:
md: can not impport hdb1, has active inodes!
md: error, md_import_device() returned -16

I assume that's because the boot is still from /dev/hdb but if so, 
how come the howto says this should work.  Seems that nothing I do 
can shift this and if I set the partition back to linux I find I 
can't mount the drive despite rebooting as I get:

mount: /dev/hdb1 already mounted or /mnt1 busy

/mnt1 isn't busy (I can create a completely new mount point: no 
difference) and mount shows that /dev/hdb1 isn't mounted.

I've tried all sorts of tweaking with lilo.conf to remove any calls 
to /dev/hdb but either these don't change anything, or else lilo 
complains that it can't install to the target (e.g. /dev/md0).

I've read through the docs and man pages and done some 
searching around but can't find any explanations.

Help of any sort, including direct pointers to what I've missed or 
misread, desperately needed!

Chris

PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Cameron Moore]

I've been battling the same problem using Debian testing/sarge with SCSI
devices.  I followed (mostly) the same howto and have subsequently tried
many other things with no success.  I'm willing to help debug this as
well if anyone has any advice.  Thanks

* chris1@psyctc.org (Chris Evans) [2004.03.02 16:17]:
> Debian stable 2.4.19 kernel with RAID1 compiled in, VIA EPIA CL1000 
> motherboard, 2 Maxtor DiamondMax 9 7200rpm 80Gb drives as /dev/hdb 
> and /dev/hdc from onboard controller.
> 
> I've followed the guide at:
> http://www.cs.montana.edu/faq/faqw.admin.py?query=Convert+Root+System+
> to+Software+Raid&querytype=simple&casefold=yes&req=search
> 
> which had turned up on a debian list search to try to set up the 
> RAID1 mirror of the boot/root drive.  I installed to /dev/hdb1 
> (/dev/hda is the CDROM and perhaps I should have changed that first). 
> 
> Loaded 2.2.20, got 2.4.19 sources, compiled RAID1 support into the 
> kernel (still can't get rid of one complaint about a missing 
> character set module but don't think that's causing any real 
> problems), made the identical /dev/hdc1 into a somewhat smaller linux 
> 
> autodetect RAID format partition, mounted it as 2nd drive in a RAID1 
> drive using:
>   mdadm --create /dev/md0 --level=1 --raid-disks=2 missing /dev/hdc1
> which worked fine, mkfs -t ext3 /dev/hdc1, mount it to /mnt1, 
> cp -ax / /mnt, tweak /etc/fstab ... /dev/md0 mounts fine, tweak lilo 
> conf to boot from /dev/md0, reboot -- fine, finally come to add 
> /dev/hdb1 into the array after resetting the partition type to 
> autodetect RAID ... 
> 
> .. no go, system complains that /dev/hdb1 is mounted or that an inode 
> 
> is active:
> md: can not impport hdb1, has active inodes!
> md: error, md_import_device() returned -16
> 
> I assume that's because the boot is still from /dev/hdb but if so, 
> how come the howto says this should work.  Seems that nothing I do 
> can shift this and if I set the partition back to linux I find I 
> can't mount the drive despite rebooting as I get:
> 
> mount: /dev/hdb1 already mounted or /mnt1 busy
> 
> /mnt1 isn't busy (I can create a completely new mount point: no 
> difference) and mount shows that /dev/hdb1 isn't mounted.
> 
> I've tried all sorts of tweaking with lilo.conf to remove any calls 
> to /dev/hdb but either these don't change anything, or else lilo 
> complains that it can't install to the target (e.g. /dev/md0).
> 
> I've read through the docs and man pages and done some 
> searching around but can't find any explanations.
> 
> Help of any sort, including direct pointers to what I've missed or 
> misread, desperately needed!
> 
> Chris
> 
> PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
>    and Therapeutic Communities; practice, research, 
>    teaching and consultancy.
> Chris Evans & Jo-anne Carlyle
> http://psyctc.org/ Email: chris@psyctc.org
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Cameron Moore
/ The other day, I went to a tourist information booth and asked, \
\  "Tell me about some of the people who were here last year".    /

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

On 2 Mar 2004 at 17:24, Cameron Moore wrote:

> I've been battling the same problem using Debian testing/sarge with
> SCSI devices.  I followed (mostly) the same howto and have
> subsequently tried many other things with no success.  I'm willing to
> help debug this as well if anyone has any advice.  Thanks

Aha, that's interesting, so it's true for Sarge too.  Thanks Cameron. 
 I do think there's a real problem here and that it needs fixing and 
documenting ... and I'm sure someone out there has worked out the 
fix... _please_!

C
PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Neil Brown]

On Tuesday March 2, chris1@psyctc.org wrote:
> Debian stable 2.4.19 kernel with RAID1 compiled in, VIA EPIA CL1000 
> motherboard, 2 Maxtor DiamondMax 9 7200rpm 80Gb drives as /dev/hdb 
> and /dev/hdc from onboard controller.
> 
> I've followed the guide at:
> http://www.cs.montana.edu/faq/faqw.admin.py?query=Convert+Root+System+
> to+Software+Raid&querytype=simple&casefold=yes&req=search
> 
> which had turned up on a debian list search to try to set up the 
> RAID1 mirror of the boot/root drive.  I installed to /dev/hdb1 
> (/dev/hda is the CDROM and perhaps I should have changed that first). 
> 
> Loaded 2.2.20, got 2.4.19 sources, compiled RAID1 support into the 
> kernel (still can't get rid of one complaint about a missing 
> character set module but don't think that's causing any real 
> problems), made the identical /dev/hdc1 into a somewhat smaller linux 
> 
> autodetect RAID format partition, mounted it as 2nd drive in a RAID1 
> drive using:
>   mdadm --create /dev/md0 --level=1 --raid-disks=2 missing /dev/hdc1
> which worked fine, mkfs -t ext3 /dev/hdc1, mount it to /mnt1, 

Wrong.
 mkfs -t ext3 /dev/md0
then mount /dev/md0. 
Once you have included /dev/hdc1 in an array, don't touch it again -
just access the array (/dev/md0).

> cp -ax / /mnt, tweak /etc/fstab ... /dev/md0 mounts fine, tweak lilo 
> conf to boot from /dev/md0, reboot -- fine, finally come to add 
> /dev/hdb1 into the array after resetting the partition type to 
> autodetect RAID ... 

You missed a step (step 9).  You have to reboot so that /dev/md0 is your root
device.
Once you have done that and are happy with it, you add in /dev/hdb1
and let it resync.

NeilBrown

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

On 3 Mar 2004 at 10:40, Neil Brown wrote:

> Wrong.
>  mkfs -t ext3 /dev/md0
> then mount /dev/md0. 
> Once you have included /dev/hdc1 in an array, don't touch it again -
> just access the array (/dev/md0).

Sorry, I was being hasty in writing the Email, that's what I did, 
i.e. mkfs the /dev/md0 drive.  That's not the problem.

> You missed a step (step 9).  You have to reboot so that /dev/md0 is
> your root device. Once you have done that and are happy with it, you
> add in /dev/hdb1 and let it resync.
Ditto: did that, no go.

Thanks,

C
PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Neil Brown]

On Wednesday March 3, chris1@psyctc.org wrote:
> On 3 Mar 2004 at 10:40, Neil Brown wrote:
> 
> > Wrong.
> >  mkfs -t ext3 /dev/md0
> > then mount /dev/md0. 
> > Once you have included /dev/hdc1 in an array, don't touch it again -
> > just access the array (/dev/md0).
> 
> Sorry, I was being hasty in writing the Email, that's what I did, 
> i.e. mkfs the /dev/md0 drive.  That's not the problem.
> 
> > You missed a step (step 9).  You have to reboot so that /dev/md0 is
> > your root device. Once you have done that and are happy with it, you
> > add in /dev/hdb1 and let it resync.
> Ditto: did that, no go.

Sorry, I missed where you said that you rebooted.

It sounds very odd.

What does "cat /proc/mounts" say?

Does your kernel use an initrd?

Exactly how did you tell lilo to use /dev/md0?
With
   root=/dev/md0
as an option in lilo.conf, or with
   append= "root=/dev/md0"

or both or something else?

NeilBrown

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

On 3 Mar 2004 at 12:04, Neil Brown wrote:

> > > You missed a step (step 9).  You have to reboot so that /dev/md0
> > > is your root device. Once you have done that and are happy with
> > > it, you add in /dev/hdb1 and let it resync.
> > Ditto: did that, no go.
> 
> Sorry, I missed where you said that you rebooted.
you are correct: I didn't say that, but I have done!
 
> It sounds very odd.
Well, I thought so too, but I see I'm not alone in experiencing this.

> What does "cat /proc/mounts" say?
Aha, didn't know that wrinkle: lovely.  Mount says:
/dev/md0 on / type ext3 (rw,errors=remount-ro)
proc on /proc type proc (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)

and cat /proc/mounts says:
rootfs / rootfs rw 0 0
/dev/root / ext2 rw 0 0
proc /proc proc rw 0 0
devpts /dev/pts devpts rw 0 0

Does that "/dev/root" bit indicate anything useful?

> Does your kernel use an initrd?
No, at least, I haven't asked it to!
 
> Exactly how did you tell lilo to use /dev/md0?
> With
>    root=/dev/md0
> as an option in lilo.conf, or with
>    append= "root=/dev/md0"

I think I've only tried the former (with and without an earlier line, 
before the image stanzas, saying root=/dev/hdb1)

I haven't used an "append" clause anywhere.

One problem is keeping in mind which of the lilo.conf tweaks 
installed with lilo but didn't solve the problem, and which were the 
ones that lilo refused to install.

I'm happy to try alternatives and report effects, on or off list, of 
each.

Many thanks,

Chris



> 
> or both or something else?
> 
> NeilBrown
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid"
> in the body of a message to majordomo@vger.kernel.org More majordomo
> info at  http://vger.kernel.org/majordomo-info.html

PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Neil Brown]

On Wednesday March 3, chris1@psyctc.org wrote:
> Aha, didn't know that wrinkle: lovely.  Mount says:
> /dev/md0 on / type ext3 (rw,errors=remount-ro)
> proc on /proc type proc (rw)
> devpts on /dev/pts type devpts (rw,gid=5,mode=620)
> 
> and cat /proc/mounts says:
> rootfs / rootfs rw 0 0
> /dev/root / ext2 rw 0 0
> proc /proc proc rw 0 0
> devpts /dev/pts devpts rw 0 0
> 
> Does that "/dev/root" bit indicate anything useful?

No, but the fact that root is actually 'ext2' even though mount (and
presumably fstab) thinks it is ext3 is a bit suspicious. 

> > Exactly how did you tell lilo to use /dev/md0?
> > With
> >    root=/dev/md0
> > as an option in lilo.conf, or with
> >    append= "root=/dev/md0"
> 
> I think I've only tried the former (with and without an earlier line, 
> before the image stanzas, saying root=/dev/hdb1)

If there are any "root=/dev/hdb1" lines in lilo.conf, I suggest taking
them out.
I think you currently have /dev/hdb1 as your root filesystem still.
You can easily check this:

   mkdir /a /b
   mount /dev/hdb1 /a
   mount /dev/md0 /b
   > /a-file
   ls -l /?/a-file

If the ls finds "/a/a-file", then /dev/hdb1 is root.
If it finds /b/a-file, then /dev/md0 is root.

If it still doesn't work, post your lilo.conf

NeilBrown

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

I'm splitting my response to this post into two.  I'm sure that 
someone out there who knows about mount and /proc/mounts can clarify 
this bit:

On 3 Mar 2004 at 12:24, Neil Brown wrote:

> On Wednesday March 3, chris1@psyctc.org wrote:
> > Aha, didn't know that wrinkle: lovely.  Mount says:
> > /dev/md0 on / type ext3 (rw,errors=remount-ro)
> > proc on /proc type proc (rw)
> > devpts on /dev/pts type devpts (rw,gid=5,mode=620)
> > 
> > and cat /proc/mounts says:
> > rootfs / rootfs rw 0 0
> > /dev/root / ext2 rw 0 0
> > proc /proc proc rw 0 0
> > devpts /dev/pts devpts rw 0 0
> > 
> > Does that "/dev/root" bit indicate anything useful?
> 
> No, but the fact that root is actually 'ext2' even though mount (and
> presumably fstab) thinks it is ext3 is a bit suspicious. 
I suppose that might be because the difference between ext2 and ext3, 
as I understand it, is just a journalling block reserved at the end 
of the normal ext2 space so perhaps /proc/mounts indicates all ext3 
as ext2?

From a quick bit of googling, I understand that /dev/root is a label 
for the root mount point that's passed to the kernel as it loads, in 
my case, I assume that's passed to the kernel from whatever lilo has 
done to the mbr and that this ensures that the kernel then holds that 
mount open (presumably in case it needs to write something back there 
when it quits ... or perhaps it always writes something back there in 
a clean dismount ... I don't know).

Can someone:
a) confirm or deny my hunch that the ext2/ext3 issue is normal?
b) clarify the way that lilo and the kernel interact?

I wonder if it's pertinent that /proc/partitions shows this:

cat /proc/partitions
major minor  #blocks  name
   9     0   78124928 md0
  22     0   80043264 hdc
  22     1   78125008 hdc1
   3    64   80043264 hdb
   3    65   80035798 hdb1

cfdisk /dev/hdb shows a single primary bootable partition occupying 
the entire drive of Linux raid autodetect type.  For /dev/hdc I have 
a single primary bootable partition of the same type and some free 
space (to ensure that there'd be enough room on /dev/hdb1 to add it 
to the array).

Thanks,

Chris
PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Paul Clements]

Chris Evans wrote:

> a) confirm or deny my hunch that the ext2/ext3 issue is normal?

A reasonable hunch, but no, it is not normal for an ext3 root fs to show
up as ext2 in /proc/mounts:

# cat /proc/mounts
rootfs / rootfs rw 0 0
/dev/root / ext3 rw 0 0
/proc /proc proc rw 0 0
[snip]

Perhaps you don't have ext3 support built in to the kernel? If not,
you'll need an initrd to boot your root fs as ext3.


As far as the active inodes on /dev/hdb1, one thing you might try is:

fuser -vm /dev/hdb1

If there's a process accessing /dev/hdb1, it will be listed.

--
Paul

Re: md: can not impport hdb1, has active inodes!

[Juri Haberland]

Paul Clements <Paul.Clements@steeleye.com> wrote:
> Chris Evans wrote:
> 
>> a) confirm or deny my hunch that the ext2/ext3 issue is normal?
> 
> A reasonable hunch, but no, it is not normal for an ext3 root fs to show
> up as ext2 in /proc/mounts:
> 
> # cat /proc/mounts
> rootfs / rootfs rw 0 0
> /dev/root / ext3 rw 0 0
> /proc /proc proc rw 0 0
> [snip]

No, it is normal. It happens, when /etc/fstab still contains ext2 as fs-type
for the root-fs. I don't recall the exact reason, but it has something
to do with the fact that the mount command normally updates /etc/mtab
when a filesystem is mounted. As the root-fs is first mounted read-only,
mount cannot update /etc/mtab. When the root-fs gets remounted
read-write, mount updates /etc/mtab, but (I think) has at that stage no
clue of what filesystem type the root-fs is and therefore uses the entry
from /etc/fstab. For an authorative answer search the mailing list archive
from the ext3 mailing list.

Regards,
Juri

-- 
Juri Haberland  <juri@koschikode.com> 

Re: md: can not impport hdb1, has active inodes!

[Maarten J H van den Berg]

On Wednesday 03 March 2004 01:36, Chris Evans wrote:
> On 3 Mar 2004 at 10:40, Neil Brown wrote:
> > Wrong.
> >  mkfs -t ext3 /dev/md0
> > then mount /dev/md0.
> > Once you have included /dev/hdc1 in an array, don't touch it again -
> > just access the array (/dev/md0).
>
> Sorry, I was being hasty in writing the Email, that's what I did,
> i.e. mkfs the /dev/md0 drive.  That's not the problem.

Hope it's not too obvious, but...
Did you also actually _run_ lilo ?  
Is fstab on /dev/md0 edited to reflect the new mountpoints ?

Not that it helps you here, but I followed the procedure -albeit not from the 
same howto[1]- multiple times with many machines. It _should_ work...

  [1] I used a howto by the name of Boot+root+raid+llilo. Maybe see if there
   are any obvious differences between the two procedures / howtos...?  

Maarten

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

On 3 Mar 2004 at 2:11, Maarten J H van den Berg wrote:

> Hope it's not too obvious, but...
> Did you also actually _run_ lilo ?  
> Is fstab on /dev/md0 edited to reflect the new mountpoints ?
No it's not too obvious and maybe I need to work through all the 
options again and document what went wrong each time but I did try to 
run lilo on each: some ran without complaint but didn't solve the 
problem, and some resulted in lilo complaining something along the 
lines that it was using the current boot device and that device x (a 
numeric representatiion, sorry, didn't note it) wasn't a device in 
which it could write its stuff.

> Not that it helps you here, but I followed the procedure -albeit not
> from the same howto[1]- multiple times with many machines. It _should_
> work...
Well, it encourages me!
 
>   [1] I used a howto by the name of Boot+root+raid+llilo. Maybe see if
> there are any obvious differences between the two procedures /
> howtos...? 
Yes, found that.  Mostly the differences are that the one I worked 
from uses mdadm and that one uses raidtools2 but I thought they said 
the same things really and I couldn't get either approach: mdadm or 
raidtools/raidtab, to work for me.

One thing: I asssume that mdrecoveryd isn't holding an inode active?  
I _think_ I've failed just as totally after killing mdrecoveryd but 
can't vouch for having done that every time.

Thanks Maarten,

C

PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Maarten J H van den Berg]

On Wednesday 03 March 2004 02:20, Chris Evans wrote:
> On 3 Mar 2004 at 2:11, Maarten J H van den Berg wrote:

Neil had some interesting points, but in the meantime here's my working 
lilo.conf (which was written by the SuSE installer) in case it helps you:

boot = /dev/hda
change-rules
    reset
default = linux
disk=/dev/hda
    bios=0x80
    disk=/dev/hdc
    bios=0x81
lba32
prompt
read-only
timeout = 80

image = /boot/vmlinuz
    label = linux
    initrd = /boot/initrd
    root = /dev/md0


Greetings,
Maarten

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

I thought I'd got this all cracked in the early hours of this 
morning.  I _think_ I'd been putting boot=/dev/hda1 when I tried to 
write the revised lilo config to the MBR and perhaps that messed up 
hdb.  I don't know, anyway, I started again, did everything in that 
howto pretty much to the letter and this time, after shifting boot to 
/dev/hdc and rebooting, I could add /dev/hdb1.  However, lilo would 
not let me use a raid-extra-boot line and when I rebooted, the system 
hung right at the start.

I moved hdb1 to hda1 and started again, this time it's all worked 
except for boot=/dev/md0 and the raid-extra-boot.  Now lilo allows 
these and says it's written to both MBRs, but when I reboot lilo gets 
to the first twenty or so of the dots after "Loading Linux" and hangs 
there ... resolutely.  

A lot of pratting around with rescuing from the installation CD (must 
work out how to burn a rescue boot CDROM) and I am back to being able 
to get everything find if I boot from boot=/dev/hdc with 
root=/dev/md0 ... and I think I'll give up here as I must go back to 
doing my real job and having a life.  If anyone can tell me what 
might be neeeded (I haven't tried things like bios=0x80 lines) I may 
find the energy to try them but not if this machine has become my 
working firewall!

So I'm left thinking there's something, perhaps idiosyncratic to some 
BIOS or HDs or whatever, that means some of us have real problems 
writing LILO boot instructions to the two drives in a RAID1 boot 
array.

I've leflt Maarten's listing of a SuSE lilo.conf to see if anyone has 
ideas.

Thank everyone,

Chris

> Neil had some interesting points, but in the meantime here's my
> working lilo.conf (which was written by the SuSE installer) in case it
> helps you:
> 
> boot = /dev/hda
> change-rules
>     reset
> default = linux
> disk=/dev/hda
>     bios=0x80
>     disk=/dev/hdc
>     bios=0x81
> lba32
> prompt
> read-only
> timeout = 80
> 
> image = /boot/vmlinuz
>     label = linux
>     initrd = /boot/initrd
>     root = /dev/md0
> 
> 
> Greetings,
> Maarten
> 
> 
> -- 
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> 

PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Chris Evans]

On 3 Mar 2004 at 11:09, Justin Guerin wrote:

> > So I'm left thinking there's something, perhaps idiosyncratic to
> > some BIOS or HDs or whatever, that means some of us have real
> > problems writing LILO boot instructions to the two drives in a RAID1
> > boot array.
> >
> One question on your kernel hang: are you loading the same kernel
> successfully when you boot directly off /dev/hdc?  If not, do you know
> your kernel is good?
Good questions Justin and I'm increasingly realising that I needed an 
almost forensic attitude to this and to take it much more slowly and 
tap into much more information that was there on the machine.  
However, I have no reason to believe that the kernel wasn't the right 
one but next time I will make sure I check carefully.

> Since one of your disks is larger than the other, you might consider
> using a 20 MB portion of the larger disk as a /boot partition, and
> keeping it out of the raid.  Booting will be very easy in that
> scenario, and you can use the rest of the disk for the raid, and put
> everything else on it.
I am increasingly tempted to do this and there is room there (there's 
936Mb as it happens: I think the first hard disc I looked after for 
anyone was 10Mb and it was the sole hard drive in that XT box!)

My sense is that this would be simpler and I'd feel less scared of it 
but I'd be slightly less robust as there'd be no reserve boot point 
if that failed (though if it did I should be able to rescue from a 
boot floppy or CD I guess).   I think that's not that different from 
continuing to have "boot=/dev/hda" (or "boot=/dev/hdc") in lilo.conf, 
as you note you have, I think that too is givign you a single MBR 
boot record.

I am still being slow about this though.  One thing that's very clear 
now is that if I let lilo (22.2) write its boot to the two drive's 
mbrs with the raid-extra-boot, something goes badly wrong.  As I 
really need to finish this saga, even if I still don't really 
understand what was wrong, I am going to stick with my current lilo 
setting which seems to work which says:
boot=/dev/hda

However, if I do want to use that bit of spare drive to give myself 
the reassuring feeling that the lilo/mbr issues are being kept away 
from the /dev/md0 areas, then is this the right sequence:

a) cfdisk to create bootable, linux type, partition /dev/hdc2
b) reboot
c) mkfs -t ext3 /dev/hdc2
d) rewrite lilo.conf to instruct it to boot from /dev/hdc2, if so, 
does that mean simply writing "boot=/dev/hdc2"?  Surely not as I 
think that means I need some primary boot loader to come out of one 
of the drive mbrs that will then point to the lilo secondary load 
from /dev/hdc2 (sorry, I'm sure this is dumb of me but someone take 
pity here please!)
e) assuming that works and reboots OK
f) init 1
g) stop /dev/md0 (after umount of / ?)  can this be done
h) cfdisk /dev/hda and take bootable off, ditto /dev/hdc
i) reboot and pray
j) ... ugh, no this all sounds wrong

I am continuing to ask (and thanks again to Justin, Chris, Neil and 
Maarten for their inputs) as I do want to feel I understand this and 
get as safe a set up as I can for this machine, but also because I 
will have to return to the issues in the next month or two, hopefully 
while it's still fresh in my mind, to put in a replacement server 
behind this firewall.  

Hence one more question: I had been planning to put at least three 
drives in that in a RAID5 array and boot/root from that, now I'm 
rattled but would still like that redundancy.  How difficult is RAID5 
boot/root cf RAID1?

TIA,

Chris

P.S. I promise to document all of this as some sort of mini-HOWTO or 
whatever to complement the existing ones, and to notify the authors 
of those where I think they might usefully be improved: clearly I owe 
the open source movement at least that much.
PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org

Re: md: can not impport hdb1, has active inodes!

[Maarten J H van den Berg]

Hi Chris.

Just a few points and musings...  may be helpful, may be not...

On Wednesday 03 March 2004 17:54, Chris Evans wrote:
> I thought I'd got this all cracked in the early hours of this
> morning.  I _think_ I'd been putting boot=/dev/hda1 when I tried to
> write the revised lilo config to the MBR and perhaps that messed up
> hdb.  I don't know, anyway, I started again, did everything in that
> howto pretty much to the letter and this time, after shifting boot to
> /dev/hdc and rebooting, I could add /dev/hdb1.  However, lilo would
> not let me use a raid-extra-boot line and when I rebooted, the system
> hung right at the start.

Yeah I forgot to remind you to change hda [my setup] to hdb [yours].

I may have a partial solution for you...  I tend to have BIG problems booting 
off anything but the first BIOS drive, maybe that's lilo, maybe that me not 
fully understanding lilo (or maybe a BIOS issue even).  In any case, this 
leads to me _always_ having hda as bootdisk. So, when I built my raid0 sets I 
think I might have done it thusly:

(1) Install your OS on hda
Define raidtab: hda=failed-disk hdc=raid-disk; activate raid, format, cp data
Mount /dev/md0 /mnt
Change ONLY the fstab and lilo.conf on the mounted /dev/md0 volume:
	tell fstab to find / as /dev/md0
	tell lilo.conf to boot off /dev/hda (!hdA! not hdc nor md0)
Now when I would run 'lilo -r /mnt' it will complain "not on the first disk" 
or something like that...  So instead, I do:
Down system; swap over hda with hdc; boot (keep a bootfloppy around!!)
run lilo (which must / should work now without complaining)
add the (now free) hdc (which used to be hda) to your raid volume.
(3) Profit !  ;-)

I know, its a hassle, but maybe this does help you a bit though.


Another possibility, but which requires changing your partitions:

After some problems I decided it was simpler to just work around lilo problems 
by having a separate tiny non-raid /boot partition[*]. This has its drawbacks 
but it solves the lilo issues.  The downside is that you must manually 
mirror /dev/hda1 to /dev/hdc1 [typically using dd], (also after a kernel 
upgrade!) and that when disk hda fails it will NOT boot from hdc by itself 
(it requires an admin with a boot/rescuefloppy physically at the console). 
If (big IF) you can live with that you may want to try it but be warned that 
it is somewhat of an ugly hack...

[*] Note: I did this partly for raid but also partly for reiserfs. I thought 
it prudent to have a plain old ext2 /boot partition with the full kernel as 
opposed to needing an initrd with reiser support on a single reiserfs 
partition. YMMV...

> I moved hdb1 to hda1 and started again, this time it's all worked
> except for boot=/dev/md0 and the raid-extra-boot.  Now lilo allows
> these and says it's written to both MBRs, but when I reboot lilo gets
> to the first twenty or so of the dots after "Loading Linux" and hangs
> there ... resolutely.

Weird...  I have never seen that. "LI" and "LIL" errors, yeah, but not that.

> A lot of pratting around with rescuing from the installation CD (must
> work out how to burn a rescue boot CDROM) and I am back to being able
> to get everything find if I boot from boot=/dev/hdc with
> root=/dev/md0 ... and I think I'll give up here as I must go back to
> doing my real job and having a life.  If anyone can tell me what
> might be neeeded (I haven't tried things like bios=0x80 lines) I may

Hmm. Bugger...  I'm no lilo expert (far from it in fact) but my understanding 
is / was that especially these lines are ESSENTIAL...! 
Why did you omit these lines...  They are there for a reason.

I hope you do find a solution...  good luck!

Maarten