I tracked my problem down to really, *really* bad behaviour of SQLite databases on a btrfs file system. That, and updatedb for the locate program was taking may hours to scan my disk. Conseqeuently, very little of my disk was in RAM and performance was awful.
Between tweaking updatedb's conf file, changing btrfs compression from gzip to lzo, and getting the 2.6.38 kernel with various btrfs fixes, things have improved dramatically. Also, I wrote the following script to defragment btrfs. This runs overnight and seems to help: #!/bin/bash # This finds files with lots of fragments, then defragments them. Thunderbird has sqlite databases # that get *very* fragmented. { for tree in $(mount | awk '$2=="on" && $4=="type" && $5=="btrfs" {print $3;}') do ionice -c3 find -L $tree -xdev -type f -size 320k -mtime -60 -execdir filefrag {} + done } | awk '{n=$(NF-2) + 0; if(n>40) {i=match($0, ": [0-9]+ extent.*found"); print substr($0, 1, i-1);}}' | { while read f do btrfs filesystem defragment "$f" done } ** Package changed: thunderbird (Ubuntu) => btrfs (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/681183 Title: Thunderbird hangs and greys out for 10-20 seconds To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/btrfs/+bug/681183/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs