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#256443 - 19/05/2005 18:04 LVM problems
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
I've just rebooted my server after approx 3 months uptime and upon reboot my vgscan tells me it can't find one of devices that made up the volume group. There doesn't seem to be anything wrong with drive but none of the lvm tools will recognise it. The drive was added recently and the group extended across to it. Any chance of recovering the data on the drive that's still intact?
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Andy M

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#256444 - 19/05/2005 18:42 Re: LVM problems [Re: andym]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Bugger, it looks like I can only restore the partitions that were on the good disk. As soon as they were extended onto the dead drive the whole partition was lost.

EDIT: So that means my /tmp directory is intact but I've lost /home and all my myth recordings. If it's not burglars it's hardware failure.


Edited by andym (19/05/2005 18:46)
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Andy M

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#256445 - 19/05/2005 19:17 Re: LVM problems [Re: andym]
bonzi
pooh-bah

Registered: 13/09/1999
Posts: 2401
Loc: Croatia
Ouch! That's the problem with logical volumes or volume groups spanning several drives - more points of failure...

The particular volume manager does not have some kind of off-line repair or data salvage tool?

Sorry for not being of any help.
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Dragi "Bonzi" Raos Q#5196 MkII #080000376, 18GB green MkIIa #040103247, 60GB blue

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#256446 - 19/05/2005 19:38 Re: LVM problems [Re: bonzi]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Yes, multiple drives leaves you open to multiple failures. I didn't go with RAID as I couldn't afford to implement it at the time.

I've managed to salvage the /etc /usr /var /lib and /root directories. The only thing I've lost is /home and the videos directory. Luckily all my really important stuff is backed up on DVD or on the iBook. Sadly I've lost all my video, which was so large it made it nigh on impossible to back up in any reasonable sense.

I'm now thinking 3x200GB drives in RAID5 with LVM2 on top in external caddies running off an EPIA itx board.
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Cheers,

Andy M

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#256447 - 19/05/2005 19:51 Re: LVM problems [Re: andym]
MRB
new poster

Registered: 17/04/2005
Posts: 16
Andy, try recovering you data with R-Studio www.r-tt.com
I have used it many times without any failure to recover yet

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#256448 - 20/05/2005 01:24 Re: LVM problems [Re: andym]
SuperQ
addict

Registered: 13/06/2000
Posts: 429
Loc: Berlin, DE
ouch, no fun.. I never use LVM for non-raid user data anymore.. it's ok for OS stuff, because it can be esily replaced.. but user data MUST be on raid for me now..

Personaly, I'm working on saving/building a new disk server for my home.. 5x 300GB SATA and a 3ware controler.. Mmmm.. 1TB in my house.. lots of room for FLACs and VOBs
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80gig red mk2 -- 080000125
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#256449 - 20/05/2005 06:22 Re: LVM problems [Re: andym]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
Once you have RAID5 why do you need LVM anymore?

Doesn't RAID 5 effectively give one big virtual drive that you simply create one standard partition (if that's what you want) across?

Certainly that's how I hope the Dell Server with hardware RAID I just ordered works.
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#256450 - 20/05/2005 12:24 Re: LVM problems [Re: Shonky]
eliceo
enthusiast

Registered: 18/02/2002
Posts: 335
Isn't LVM a way to get around not having to grow raid 5 partitions? I mean you can create 1 raid 5 array then add another raid 5 array in the future without destryoing the original data?

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#256451 - 20/05/2005 15:39 Re: LVM problems [Re: eliceo]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Yes, it was the ability to grow filesystems without disturbing existing data that I liked.
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Andy M

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#256452 - 21/05/2005 02:48 Re: LVM problems [Re: andym]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
Technically of course LVM doesn't allow you to grow filesystems. It allows you to grow drives (volume groups in LVM-speak).

You still need special separate tools to grow and shrink filesystems such as ReiserFS and EXT2/3.
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#256453 - 21/05/2005 07:30 Re: LVM problems [Re: Shonky]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Yes, if you want to split hairs. You resize the partition and then resize the filesystem to suit.
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Cheers,

Andy M

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#256454 - 21/05/2005 07:53 Re: LVM problems [Re: andym]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
I was trying to inform others reading as much as anything.
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#256455 - 21/05/2005 08:37 Re: LVM problems [Re: Shonky]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Suppose so, although I'd imagine most people who aren't aware of LVM would've read the first post and gone elsewhere.
_________________________
Cheers,

Andy M

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#256456 - 21/05/2005 14:30 Re: LVM problems [Re: andym]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
I don't think that's splitting hairs. It's often easy to increase the size of a partition (for example, on a plain disk, delete the partition 2 and mark partition 1 to now go to the former end of partition 2) , but you have to have complex tools that understand the filesystem at its lowest level in order to increase filesystem size, and many people, even professionals, can forget that distinction -- that partitions and filesystems are not the same thing. I've spent many hours of my life telling that to (admittedly, not very good) Unix admins.
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#256457 - 21/05/2005 14:37 Re: LVM problems [Re: wfaulk]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Oh well, that's me told then....
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Cheers,

Andy M

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#256458 - 21/05/2005 15:42 Re: LVM problems [Re: andym]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Sorry. I'm in a pissy mood apparently -- tooth pain'll do that to you.
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Bitt Faulk

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#256459 - 22/05/2005 16:04 Re: LVM problems [Re: eliceo]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
From my investigation last year, expanding most filesystems and LVM groups is easy. And supported in code. The Linux RAID stuff on the other hand had big red flashing warnings around all the expansion stuff saying not to use it except to test the code.

LVM is also better at handling hardware RAID expansion then a raw filesystem or software RAID layered on top. I run an array at work on a fibre attached Smart Array with LVM. I can expand it, let the hardware finish it, then get around to expanding the LVM and filesystem with little to no user interruption.

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