Topic: broken system after power fail

[jameswilson]

i have a 32 bit sme install running raid 6 with a spare on 7 drives.
We had a power fail this morning which was to long for the ups.
On power up the kernel panics, not syncing
using a rescue cd it says it cant find any linux partitions.

I have no clue what to do to rescue this thing, any help gratefully recieved.

Yours desperatly
James

[janet]

jameswilson

I have no clue what to do to rescue this thing, any help gratefully recieved.

One approach is to rebuild the system from CD (new install) & restore from backup
You should then configure the UPS/SME server/Nut to gracefully shut your SME server down so that a similar issue does not happen in the future.

[jameswilson]

i can restore the sme bits but i was running various windows vm's in virtualbox. These were not backed up and i need a file from one of them.

[jameswilson]

on researching all of the 7 drives have no md superblock, on sda through to sdg

[jameswilson]

mdadm --assemble --force /dev/md0 /dev/sd[abcdefg]1

found in other places that this command worked but im not brave enough to use it?

[stephdl]

using a rescue cd it says it cant find any linux partitions.

do you mean the system-rescue-cd

http://www.sysresccd.org/SystemRescueCd_Homepage

normally it can mount automatically the raid system, you can see https://wiki.contribs.org/Recovering_SME_Server_with_lvm_drives

i suppose that you have lvm activated.

[jameswilson]

i was using the sme cd and selecting rescue mode.

Its a standard install i didnt select no spare etc at install time.

[stephdl]

i was using the sme cd and selecting rescue mode.

Its a standard install i didnt select no spare etc at install time.

therefore you should try this howto https://wiki.contribs.org/Recovering_SME_Server_with_lvm_drives#Method_A_with_SystemRescueCd

after the boot you can check if the raid is activated by performing

cat /proc/mdstat

[jameswilson]

it cant ensemble the array cos non of the drive have any superblock info.

on boot
cat /proc/mdstat gived

Personalities : [raid0] [raid1] [raid 10] [raid 6] [raid 5] [raid 4]
unused devices: <none>

[stephdl]

well it is not good, really not

[jameswilson]

its not a superblock problem i was using the wrong command

I have issued the command

mdadm --stop /dev/md2

then

mdadm --assemble --force /dev/md2 /dev/sd[abcdefg]2

mdadm then reports

mdadm: /dev/md2 has been started with 5 drives (out of 6).

cat proc/mdstat then reports the array as active.

But i cant mount it?

Any other ideas

[jameswilson]

so the array starts im hopefull i can save this.
when doing
mdadm --examine /dev/sda2 i get different output depending on the drive.
can i make sme do a force on boot or stop it thinking it has a problem to it doesnt need the force?

[stephdl]

if the raid starts, now you have to start the lvm as described in the howto

[jameswilson]

that has worked. i can now browse the array. How do i make sme boot so i can save the data i need or replace drives etc as needed?

[jameswilson]

ie the fact i can now access the data means i should be able to boot sme normally and replace the drive that appears to causing the problem