Quick LVM

[Haden]

In my current server setup I've got 8 disks (36-180GB size, both ide and scsi) which all are used to store non-critical data.
Problem is I need to keep eye on each disk free space, move stuff around etc. : getting one virtual device would be perfect solution for me.
Further, I don't want to waste space on mirroring, but I don't want loose all data in case one disk dies too.

How can I setup LVM so in case of one disk failure only files located there would be lost (I've found little information about quorum feature, which hints it should be possible)?

TIA

OS Debian Linux

 

[Nothinman]

You probably want RAID-5 where you lose 1 disk worth of capacity to parity and if one dies the data isn't lost. There's no way to use RAID 0 without risking the loss of the entire filesystem. Also when you setup a RAID set with MD if you mix sizes you end up only limited to the size of the smallest disk, LVM may handle this better than MD but I couldn't say.

 

[Haden]

I cannot choose RAID5, with 36GB being smallest disk, I would waste enormous amount of space.
JBOD mode would be option, but I don't think fsck would recover anything if first disk is gone.

Redundancy is nice, but I don't need it here, loosing one disk data would be nothing more than "oh-well", just that all filesystem is too much...

 

[Nothinman]

You'll probably be able to stripe only the disks that are the same size then, which might reduce the number of devices to manage, but having all the different size disks is a problem you can't really avoid.

One other thing you might be able to do is LVM partitions, divide all the disks up into equal size partitions (say 9G) then LVM the partitions. It might hurt performance, actually ordering the partitions in the set could alleviate that I guess, but you could probably get 1 big LVM block device out of it.