So before I do this.....

Khannie

Ok....my main hard drive is dead. I'm currently working off a livecd but I need to get sorted ASAP. I still have 3 x 750G hard drives in a software raid 5 config. They're XFS formatted. There is about 100G free on them. I would like to install ubuntu 10.10 on the remaining space but it wont boot off a raid 5 array, so I'm thinking this:

Install everything except /boot to the raid 5 array (XFS cannot be resized downwards or I would look at this). Install /boot to a USB stick, make it bootable and just leave it there, pointing at the raid 5 array for the root partition.

Is this mental?

Khannie

Ach....I'm impatient. Going for it.

bhickey

Nooooooohhh!

Khannie

LOL.

It worked out grand actually. The newer versions of grub do support reading from the software raid 5 so I just installed to that.

Of course when I went to boot it went tits up. Couldn't find the md device. Live cd, mount proc etc., chroot into md, update the initramfs and presto chango. Works a charm. I'm a bit concerned about using XFS on my root partition. The hard drives seem to be thrashing quite a bit at the moment but I'll clear the drives out a bit and defrag (again) and see how it is then.

Mathiasb

A mate does this (boots from USB). It has the init scripts for unencrypting his HDD, which of course is fully encrypted and without a bootloader, so you can't use the laptop without the USB key. (yes, he's paranoid)

Good stuff. xfs apparently scales well with large file systems (and has done for quite some time) where as ext4 is about the same speed now, afaik.

Naikon

Khannie wrote: »

I'm a bit concerned about using XFS on my root partition. The hard drives seem to be thrashing quite a bit at the moment but I'll clear the drives out a bit and defrag (again) and see how it is then.

XFS is simply an awesome file system. Full 64 bit address space is insane for a file system around since 1994. I have not done any performance tests(yet), but it does feel a lot nippier when transferring large blocks of data.
All my partitions are XFS formatted. Don't worry about the root partition issue. I could be wrong, but most of the "issues" with XFS as a root partition seem to be grub related. Really does put something like NTFS to shame imo.
On a side note, I am using Debian Squeeze at the moment with LVM. No issues yet. Fragmentation might be an issue, but that is for another day. I somehow reckon the XFS guys knew what they were doing. Should be fine.

Khannie

Ah yeah, XFS is brilliant for large files (which is what the raid array was originally for...until yesterday it was my media partition). It deletes tens of gigs in a second. Not so nippy with small files though. Overall I'd prefer if it was EXT4 now, but I'm happy enough.