There's been some banter on planet debian lately about resizing filesystems (ext3 and reiserfs) so I'm going to try. Turns out a dev-101 (failover-steel) has some openvz ve's which could use some more breathing room.
failover-steel:/home/optimus-prime# vgscan Reading all physical volumes. This may take a while... Found volume group "big_space" using metadata type lvm2
OK, how about logical volumes?
failover-steel:/home/megatron# lvscan ACTIVE '/dev/big_space/bart' [3.91 GB] inherit ACTIVE '/dev/big_space/homer' [10.00 GB] inherit ACTIVE '/dev/big_space/misc' [2.00 GB] inherit
Let's make bart bigger. Bart is like sid
Now, according to Wouter, I can do something like this:
lvresize -L +5G /dev/
/home && resize2fs /dev/ /home
I'll start with the lvresize (not lvextend).
failover-steel:/home/starscream# lvresize -L +1G /dev/big_space/bart Extending logical volume bart to 4.91 GB Logical volume bart successfully resized
Wow, that was easy! Now how about the filesystem... first I'll stop the ve:
failover-steel:/home/bumblebee# vzctl stop 111 Stopping VE ... VE was stopped/usr/lib/vzctl/scripts/vps-functions: line 146: [: del: integer expression expected VE is unmounted failover-steel:/home/bumblebee#resize2fs /dev/mapper/big_space-bart resize2fs 1.40.6 (09-Feb-2008) Filesystem at /dev/mapper/big_space-bart is mounted on /var/lib/vz/private/111; on-line resizing required old desc_blocks = 1, new_desc_blocks = 1 Performing an on-line resize of /dev/mapper/big_space-bart to 1286144 (4k) blocks. The filesystem on /dev/mapper/big_space-bart is now 1286144 blocks long.
Wow, that took hardly any time at all! I even did it again with the ve still running, that's very impressive. I've been using lvm2 for awhile without too much fanfare, thought I had heard so many good things about it, and had definitely run into problems where my filesystems were the wrong size enough times I tried it out. Now I'm a believer. :-)
More: LVM at the Docunext Wiki
Note - Slightly different with reiserfs:
resize_reiserfs -s +500M /dev/morex/test
Also - I tried shrinking an online ext3 volume. I now feel like that was a very bad idea, and will not try again.