[gentoo-user] fixing raid1 /boot

[gentoo-user] fixing raid1 /boot

[Kevin Haddock]

For the life of me I can't figure out the canonical way to rebuild my mirrored /boot.  The second disk (/dev/sdb1) got corrupted and it is interfering with my rebuilding the kernel (genkernel can't mount /boot).

I tried following this page:


http://www.linux.org/docs/ldp/howto/Software-RAID-0.4x-HOWTO-4.html

But I can't figure out what package ckraid is in.  Equery belongs is not help and searching gentoo-portage.com returns nothing.

Does anyone know of some gentoo specific instructions in this regard?

Thanks in advance,
-Kevin

-----

People originally thought the eternal question was:

      "Why am I here?"

But now we know the question is actually:

      "Why is THAT THERE?"

-Me


      

Re: [gentoo-user] fixing raid1 /boot

[Volker Armin Hemmann]

On Samstag 08 August 2009, Kevin Haddock wrote:
> For the life of me I can't figure out the canonical way to rebuild my
> mirrored /boot.  The second disk (/dev/sdb1) got corrupted and it is
> interfering with my rebuilding the kernel (genkernel can't mount /boot).
>

forget genkernel.

put in correctly partitioned disk.


read man mdadm

/sbin/mdadm /dev/md0 –fail /dev/sdb1 –remove /dev/sdb1
/sbin/mdadm /dev/md0 –add /dev/sdb1

as example. Found on google in less than 2 minutes.

Seriously, google is your friend ;)

Re: [gentoo-user] fixing raid1 /boot

[Kevin Haddock]

beta ~ # /sbin/mdadm /dev/md0 --fail /dev/sdb1 --remove /dev/sdb1
mdadm: cannot get array info for /dev/md0
beta ~ # cat /proc/mdstat 
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md0 : inactive dm-0[0](S)
      104320 blocks super non-persistent
       
unused devices: <none>


--- On Sat, 8/8/09, Volker Armin Hemmann <volkerarmin@googlemail.com> wrote:

> From: Volker Armin Hemmann <volkerarmin@googlemail.com>
> Subject: Re: [gentoo-user] fixing raid1 /boot
> To: gentoo-user@lists.gentoo.org
> Date: Saturday, August 8, 2009, 2:19 PM
> On Samstag 08 August 2009, Kevin
> Haddock wrote:
> > For the life of me I can't figure out the canonical
> way to rebuild my
> > mirrored /boot.  The second disk (/dev/sdb1) got
> corrupted and it is
> > interfering with my rebuilding the kernel (genkernel
> can't mount /boot).
> >
> 
> forget genkernel.
> 
> put in correctly partitioned disk.
> 
> 
> read man mdadm
> 
> /sbin/mdadm /dev/md0 –fail /dev/sdb1 –remove /dev/sdb1
> /sbin/mdadm /dev/md0 –add /dev/sdb1
> 
> as example. Found on google in less than 2 minutes.
> 
> Seriously, google is your friend ;)
> 
> 

Re: [gentoo-user] fixing raid1 /boot

[Mike Kazantsev]

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On Wed, 19 Aug 2009 15:30:46 -0700 (PDT)
Kevin Haddock <kevinhaddock@yahoo.com> wrote:

> beta ~ # /sbin/mdadm /dev/md0 --fail /dev/sdb1 --remove /dev/sdb1
> mdadm: cannot get array info for /dev/md0
> beta ~ # cat /proc/mdstat 
> Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
> md0 : inactive dm-0[0](S)
>       104320 blocks super non-persistent

If you have /dev/sda1 and /dev/sdb1 in raid1, "md0 : inactive
dm-0[0](S)" line is obviously wrong, it should be something like
"md0 : active raid1 sda1[0] sdb1[1]".

So, what's this dm-0 device?
Prehaps you had sda/sdb linked via device mapper during boot?

Try removing md0 (by "--manage --stop") and re-assemble the raid,
specifying the correct devices.

Try to remove md0 and re-create it, specifying the right devices (or
just /dev/sda1, then add sdb1).
Alternatively, you can try --assemble --scan, maybe it'll just work
now, then I guess something wrong should be happening during boot.

-- 
Mike Kazantsev // fraggod.net

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Re: [gentoo-user] fixing raid1 /boot

[Kevin Haddock]

beta ~ # mdadm --manage --stop /dev/md0
mdadm: stopped /dev/md0
beta ~ # mdadm -A /dev/md0 /dev/sda1
mdadm: cannot open device /dev/sda1: Device or resource busy
mdadm: /dev/sda1 has no superblock - assembly aborted
beta ~ # mdadm -A /dev/md0 /dev/sda 
mdadm: cannot open device /dev/sda: Device or resource busy
mdadm: /dev/sda has no superblock - assembly aborted
beta ~ # mount
/dev/evms/slash on / type xfs (rw,noatime)
proc on /proc type proc (rw,nosuid,nodev,noexec)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec)
udev on /dev type tmpfs (rw,nosuid,size=10240k,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,gid=5,mode=620)
shm on /dev/shm type tmpfs (rw,noexec,nosuid,nodev)
usbfs on /proc/bus/usb type usbfs (rw,noexec,nosuid,devmode=0664,devgid=85)
securityfs on /sys/kernel/security type securityfs (rw,noexec,nosuid,nodev)
nfsd on /proc/fs/nfsd type nfsd (rw,noexec,nosuid,nodev)

-Kevin

-----

People originally thought the eternal question was:

      "Why am I here?"

But now we know the question is actually:

      "Why is THAT THERE?"

-Me


--- On Wed, 8/19/09, Mike Kazantsev <mk.fraggod@gmail.com> wrote:

> From: Mike Kazantsev <mk.fraggod@gmail.com>
> Subject: Re: [gentoo-user] fixing raid1 /boot
> To: gentoo-user@lists.gentoo.org
> Date: Wednesday, August 19, 2009, 4:17 PM
> On Wed, 19 Aug 2009 15:30:46 -0700
> (PDT)
> Kevin Haddock <kevinhaddock@yahoo.com>
> wrote:
> 
> > beta ~ # /sbin/mdadm /dev/md0 --fail /dev/sdb1
> --remove /dev/sdb1
> > mdadm: cannot get array info for /dev/md0
> > beta ~ # cat /proc/mdstat 
> > Personalities : [raid0] [raid1] [raid6] [raid5]
> [raid4] [raid10] 
> > md0 : inactive dm-0[0](S)
> >       104320 blocks super
> non-persistent
> 
> If you have /dev/sda1 and /dev/sdb1 in raid1, "md0 :
> inactive
> dm-0[0](S)" line is obviously wrong, it should be something
> like
> "md0 : active raid1 sda1[0] sdb1[1]".
> 
> So, what's this dm-0 device?
> Prehaps you had sda/sdb linked via device mapper during
> boot?
> 
> Try removing md0 (by "--manage --stop") and re-assemble the
> raid,
> specifying the correct devices.
> 
> Try to remove md0 and re-create it, specifying the right
> devices (or
> just /dev/sda1, then add sdb1).
> Alternatively, you can try --assemble --scan, maybe it'll
> just work
> now, then I guess something wrong should be happening
> during boot.
> 
> -- 
> Mike Kazantsev // fraggod.net
>