Day: January 20, 2007

I needed to re-arrange some disk space. I explained the situation in Rants and Revelations » Why didn’t I use LVM on everything? with a table showing the current layout and everything. At the time, my plan was:

1. Migrate the content of /dev/hdc3 off using “pvmove” and “vgreduce”.
2. Delete all three partitions on /dev/hdc3 and add it back to the vg using “pvcreate /dev/hdc; vgextend xen-space /dev/hdc”.
3. Migrate the content of /dev/hde2 off using “pvmove” and “vgreduce”.
4. Delete the /dev/hde2 partition and increase the disk of /dev/hde1 to fill up the drive, and use resize2fs to make /dev/hde1 use the whole partition.

I did steps 1-3, and it all worked perfectly. I didn’t have to shut down anything, and it didn’t interrupt the normal operation of either the dom0 or the domUs. But when I’d done that, I realized I actually had enough free space on the lv that I could do an even better plan:

1. Set up a 250Gb lv.
2. Use rsync to copy everything from /dev/hde1 to the lv.
3. Once that was done, shut down domU 1.
4. Make /dev/hde1 part of the lv.
5. Make the 250Gb lv bigger using lvextend– I chose to add 100Gb to it, and I have space to add more if I need it.
6. “e2fsck -f” and “resize2fs” the lv.
7. Restart the domU 1, using the lv instead of /dev/hde1.

This worked perfectly. The domU was down about 10-15 minutes tops. /dev/hde is still partitioned into two partitions, even though both partitions are part of the same vg. But other than that, it’s exactly what I’d have done if I were setting it up from scratch now.