System no longer boots (WAS:Re: How to remove a PV from an LVM VG?)
On 5/7/12, Philippe Marzouk <phil@ozigo.org> wrote:
> On Sun, May 06, 2012 at 08:04:35PM -0700, Marc Shapiro wrote:
>> The old drive is /dev/sda and there are two PVs on the disk
>> /dev/sda3 and /dev/sda4, both are in vg1
>>
>> The new drive is /dev/sdc and it has only 1 LVM PV and that is /dev/sdc4
>>
>>
>> Is this the correct method to preserve my data:
>>
>> pvmove /dev/sda3 /dev/sdc4
>>
>> wait for it to finish
>>
>> pvmove /dev/sda4 /dev/sdc4
>>
>> once that has finished
>>
>> vgreduce vg1 /dev/sda3
>> vgreduce vg1 /dev/sda4
>>
>> pvremove /dev/sda3
>> pvremove /dev/sda4
>>
>>
>> I really need to know that this is the correct procedure and get
>> this done as quickly as possible. I don't want to lose data.
>>
>
> This is the method I use.
> pvmove fails sometimes, you just need to restart it and it will continue
> where it stopped.
>
> Philippe
Not wanting to take the chance at shutting down and rebooting, and
also not wanting unneeded disk activity, last night I exited X-Windows
and left the system at a text console with nothing running but the
bash shell that I was in. This morning the following message was
printed on the console and the system was completely locked up. I
have left out some of the message, since I had to copy it down by hand
and now have to recreate it by hand, as well:
---------------------------------------------------------------------------------------------------------------
[19265.004003] HARDWARE ERROR
[19265.004003] CPU 0: Machine Check Exception: 4
Bank 4: b200000000070f0f
[19265.004003] TSC 1c0b149de6e2
[19265.004003] Processor 2:f82 TIME 1336375869 0 APIC 0
.
.
.
[19265.004003] This is not a software problem!
[19265.004003] Machine check: Processor context corrupt
[19265.004003] Kernel panic - not syncing: Fatal machine check on current CPU
[19265.004003] Pid: 166, comm: scsi_eh-0 Tainted: G H 2.6.32-5-686 #1
[19265.004003] Call Trace
.
.
.
[19265.004003] [drm:drm_fb_helper_panic] *ERROR* panic occured,
switching back to text console
[19265.004003] [drm] nouveau 0000:01:00.0: Setting dpms mode 0 on vga
encoder (output 0)
.
.
.
[19265.004003] Fatal: Module i2c-isa not Found
---------------------------------------------------------------------------------------------------------------
After this, the system would not boot at all. It gets as far as
recognizing my LVM volume, then goes into a loop of DRM READ errors on
ATA-1 from which I have yet to see it recover, hang, or exit.
This left me feeling that this was more than a disk error, but now I
am not so sure. I was able to enter the BIOS setup and do whatever I
wanted to there without errors. I then booted into memtest-86 without
trouble and let it run for a while. After this, I went down to my
local Barnes & Noble and picked up a linux magazine with a live DVD on
it (Debian and 4 other distros on it). I booted into Debian from the
DVD and that is where I am now. No apparent problems, as long as I
don't try to boot into my own system with all of my data. (No, I do
not have a backup. I will slap myself now.)
What I was hoping to do was to try and access my data from the live
DVD and see what could be recovered. Primarily by attempting to
migrate the data from my old disk to the new one as I originally
posted. Then, possibly, rerunning lilo to place the boot sector on
the new drive, removing the old drive and setting the new drive up to
boot from it. Unfortunately, I do not see any way to access the LVM
volume. Is this possible from the live Squeeze image (6.0.1)? If
not, does anyone have any suggestions as to how I might try and
recover some of the data. If I can just get back the /home partition,
that would be good. Getting /usr/local would be a nice bonus, beyond
that will probably require a miracle.
All help appreciated.
BTW, if I do somehow manage to migrate my data off of the bad disk -
the new disk is a SATA disk - I have only used IDE disks up until now.
How do I set the system to boot from the SATA disk's MBR? Can I just
set it as the primary boot disk in the BIOS, or is there more to it?
Marc Shapiro
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