Red Hat 8 & LVM
i have 2 60gb ibm hds together in a lv.. now one of the hds crashed badly and ibm tool says it found to many corrupted sectors for repair... the other drive is still okay.. now i want to recover as many data as possible.. i started fsck.ext3 on the logical partition /dev/files/ftp and it runs for about 70 hours now... checking for bad blocks.... and i am running out of nerves...
so first question is how to get at least the data from the functional hd (redhat wont boot normally due to the bad sectors in the lv). how do i reduce the size of it or is there any other possibility worth trying to recover anything from the hd with the bad sectors?
second question: i wasnt quite confident with ext3 as filesystem, i'd rather like my reisserfs back.. how do i get redhat to using reisserfs (do i need to recompile my kernel ?! didnt plan to... ) and what do i need to do it ?
First answer: Are you running a linear or RAID0-equivalent LV (I don't remember the LVM name for it)? If you're running the RAID0-equivalency, I'd probably give up all hope of ever regaining any data. If you're running a linear LV, was it the first or second HD that crashed? If it was the first, it's probably much harder, since the inode table and block bitmap probably crashed with it. I don't remember how ext organizes the fs data.
Second answer: To get redhat to automagically user reiserfs, you'd probably just have to change the relevant in fstab and the boot script should do it for you. If it's the root device, you have to compile reiserfs into the kernel, though. I think it's modularized by default in redhat.
the lv is organized like a stripe-raid.. well... i dont know how exactly its organized, but i dont mirror the data... i have 2 60gb hdds and i put them together to 118GB LV.... i believe the second hd crashed... fsck.ext3 should finish marking bad blocks tomorrow morning, then i'll see whats left of the data..
second: the lv is not the boot or root hd... whole os is on a scsi disk, the 2 60gbs are ide and just for the ftp-server.
i cant see anything with reisserfs anywhere... could choose it at install either.. thats why i ask, i think i need to download / get it from the install cd or something.. but i never did that before.. so anybody got an idea of what i have to look for or where i have to look?
Striped was not what I wanted to see. This means that not just a large chunk was made unavailable on your LV, but rather that your LV is riddled with holes. If you don't know what I'm saying, imagine your LV as a piece of paper. Now, take a shotgun (not one of those that fires just one bullet, but one of those that fire like a hundred shrapnels) and shoot at your LV from some distance. Then you'll see what your LV looks like to Linux. You'll be lucky if any tool manages to extract even a single file out of that mess. I know how you feel, I've also had a hard drive crash recently; it's no fun at all. That's actually the thing with striping: during normal operation, you'll get a little more than twice the performance of the slowest disk in the set, but if one of them crashes, you're pretty done for it.
If you're still interrested in reiserfs:
Look for /lib/modules/`uname -r`/kernel/fs/reiserfs/reiserfs.o. If you have it, you can use a reiserfs partition, if you don't, you'll probably have to compile from your kernel source. You'll still need the tools to format a new such, though. See if you have mkfs.reiserfs or reiserfsck. If not you'll have to get them, either via RPM or via namesys.com.