[NBLUG/talk] LVM, Raid, Ubuntu 9.10 - looking for recovery help

Glen Gunsalus G-Gunsalus at mindspring.com
Fri Jan 22 15:44:31 PST 2010


Ok, looking for some help/pointers on recovering from apparent disk read error.

I recently set up a server using ubuntu 9.10 (64bit) and configured with Raid 
1 and LVM.  Maybe a mistake?

This is a Dell 5150 with Intel 2.8GHz dual core EM64T, 4Gb RAM and two 250GB 
Seagate SATA drives.

It failed to boot this morning with the error:

GRUB loading.
error: no such disk

Checked setup and the two drives are seen by bios

Did Dell hard drive diagnostic (from the boot menu - F12 on startup) and get:

Drive 0: ST3250410AS - Fail.  Return Code:  7
Drive 1: ST3250410AS - Pass

Some sniffing around points to disk read error (although lots of M$ related 
misinformation to sift through).

So... hoping both disks fully mirrored and had boot code in MBR, swapped 
drives - no joy.  Thought I wrote to MBRs on both at configuration, but I'm 
new to this and undoubtedly missed.

popped in the 9.1064bitserver install cd and went into rescue mode.

When asked for device to use as root file system, I get the two drives (with 3 
partitions each (see below)), all the LVs and /dev/md0.

At this point I chose the lv root device (/dev/gv-ubuntu-9/root).

Long time -- difficulty reading drive??

Chose "Execute a shell in /de/gv-ubuntu-9/root" and doesn't go (long wait then 
back to choice for shell execution).

Sooo... choose execute shell in install space (not the precise choice, but 
can't go  back easily just now).

fdisk and fsdisk show the partitions on sda and sdb:

sfdisk -l /dev/sda

Disk /dev/sda: 30401 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

   Device Boot Start     End    #cyls    #blocks    Id  System
/dev/sda1   *      0+   30369   30370-  243946993+  8e  Linux LVM
/dev/sda2      30370    30400      31      249007+   5  Extended
/dev/sda3          0        -       0           0    0  Empty
/dev/sda4          0        -       0           0    0  Empty
/dev/sda5      30370+   30400      31-     248976   fd  Linux raid autodetect

for /dev/sdb - substitute "b" for "a" above - all else identical

lvdisplay shows all the lv's

Ok, anything that needs disk read can be really slow (sorta sporadic though) 
so looks like incipient disk failure of sda.

Now what?

Can I somehow make the second disk?
Then move to sata-0 (leave out the second disk)
set up new disk and mirror ?













More information about the talk mailing list