Month: September 2012

A new start

I decided I needed some more room on my home Linux box, so I bought a couple of 2TB disks. I also decided it was time to do a wipe and re-install because the box has been upgraded many times and there are several things that just don’t work right any more. So I burned a bunch of different distros onto CDs and experimented with them, and decided that Kubuntu is the best combination of beauty and power. None of the other distros except Debian allows you to set up lvm on RAID-1 while installing, and Debian looks like a bit of a dogs breakfast compared to Kubuntu, even in KDE.

The two new disks are so big that as it is, I’m only using them for the new installation, so the I can mount the old system under /old_system and I can compare everything to make sure I haven’t lost any important configuration. But eventually I’ll be able to delete those partitions and add them back to the free pool in the LV and use them to expand any of the actual in-use partitions. I love lvm.

Installation has gone ok, I’ve got about 3/4s of the things I need to get working again working again, but I’ve hit the usual string of snags. The biggest is that one of the two new disks keeps dropping out of the RAID1, so I have to keep adding it back in. I’ve rejiggered all the cables as best as I can, and hopefully it will rebuild overnight and it will be ok. Fingers crossed, I’m off to bed.

Is this even possible?

Ok, here is the current situation: My machine has two identical 500Gb drives, and two identical 1Tb drives. When I first set it up, with just the 500Gb drives, I was using a version of Linux that wouldn’t boot from mirrored lvm partitions, so I set it up

  • /dev/sda1 2Gb /boot
  • /dev/sdb1 2Gb /
  • /dev/sda2 2Gb swap
  • /dev/sdb2 2Gb swap
  • /dev/sda3 and /dev/sdb3 – turned to a mirror, /dev/md0 and then created a
    pv and a vg.

That was working fine for a number of years, and then I added the two 1Tb drives, which I created as a mirror /dev/md1 and added it to the vg.

At this time, I have more more than 500Gb free space in the vg, so I definitely could pvmove and vgreduce and get rid of that. I’d also like to somehow fix it so that / and /boot and swap are on lv and just boot from the two 1Tb drives. The reason I’d like to do that is that

  • a) It’s been bugging me for years that I’m still using physical partitions
    for / and /boot, so I can’t resize them and
  • b) I have two 2Tb disks sitting on my desk that I’d like to add, and I
    don’t think I have enough SATA ports for 6 disks and
  • c) these two 500Gb drives are ancient – they just hit their 5th birthday a
    few weeks ago.

So would it be possible to migrate everything off of /dev/sda and /dev/sdb without major surgery? Or am I going to have to bite the bullet and re-install everything?