Friday, June 10, 2005

Fixing inode error on mirrored Root disks.

Subject: Followup: Fixing inode error on mirrored Root disks.

More followup here than Summary - I will summarize when I can complete the
fix (about two weeks):

The process utilized last night to fix the inode error on a Mirrored
metadevice started with a boot from a Solaris Installation cdrom. This
boot (OK> boot cdrom -s) did not work (see below messages), and things
automatically proceeded into a normal boot. (and with that I lost my
change window!)

The cdrom boot error messages were:

failed to read superblock.
failed to read superblock.
Boot load failed.

I am still researching these messages... The planned procedure to fix the
inode problem looks like this:

d10=Mirror
d11=SubMirror
d12=SubMirror

Process Steps:
1.) Init system into OBP
init 0
2.) Boot system off CDROM, single-user mode
Solaris Install CD #1
boot cdrom -s
3.) Detach one of the sub-mirrors.
/usr/sbin/metadetach d10 d11 (detach d11 SubMirror from
d10 Mirror.)
4.) Run fsck against the remaining (attached) sub-mirror.
Make sure that root partition is unmounted.
fsck -y -o f /dev/rdsk/c1t1d0s0 (will fsck by default
remaining attached submirror d12.)
5.) Init system into OBP
sync
init 0
6.) Boot system normally (note: system will come up normally, but not
mirrored)
boot
7.) Perform a metaattach command, to attach the 'un-attached' sub-mirror.
This will sync up the unattached submirror, fixing the inode problem. May
take couple hours.
/usr/sbin/metattach d10 d12 (reattach & resync d12 SubMirror
to d10 Mirror.)
/usr/sbin/metastat | grep Resync (check current percentage
of resync completion.)
8.) When completed, system is ready; Reboot optional?

My next change window is in two weeks; If the above works, I will be
summarizing that way. Much thanks to all the folks that offered help on
this - I'm learning a lot!

I'm fairly new to Solaris administration... (Retread IBM Mainframe sysprog)

We have observed the following error message on one of our V1280 servers
that has a mirrored Root partition. This server is running Solaris 9,
using Solaris Volume Manager for mirroring.

[ID 879645 kern.notice] NOTICE: /: unexpected free inode 427288, run fsck
(1M) -o f

The gentleman that set this server up (top notch sysadmin) went on to a
better opportunity, so I am learning fast. Looks like the following
sequence of steps would get me through a correction... I would appreciate
any critiquing, or pointers, from more experienced folks. Thanks in
advance - I will summarize in return.

1.) Bring down server to OBP level
2.) Boot server off CDROM, single user mode (installation CDROM #1 ?)
3.) Mount root partition "/dev/dsk/c1t0d0s0" on " /a " (1st submirror)
4.) Run fsck on " /a "
5.) umount " /a "
6.) Repeat process for second submirror.
7.) Reboot back into multi-user mode.

Again, thanks for any advice that might be offered.

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