I currently have the following setup on my laptop - harddrive is divided in 3 parts, first one is a /boot for my ubuntu, third one is a windows installation, and one in the middle is a encrypted partition, which has lvm with 3 partitions - / and /home with btfs and /swap. On those i have Ubuntu 10.10 installed.
I do encryption with cryptsetup/luks.
Unfortunately I have a very poor performance in this setup - boot takes almost 3 minutes and after boot system "warms up" to normal performance for a minute/two. I suspect that disk i/o is a problem, as stuff like apt-get is sometimes very slow on i/o intensive operations ("reading database"). I wonder why my i/o performance could be slow. I have 3 ideas - either lvm behaves bad over luks encrypted partition, or btrfs behaves badly for some reason or ubuntu installation for some reason is screwed up (which I doubt).
I wonder if any of those suggestions are possible and if not what else could so drastically affect performance.
PS: Before this installation performance was okay with luks-on-lvm setup (3 lvm partitions encrypted by luks) and ext4 fs setup, so it's this installation, not laptop.
PPS: Encryption is aes-xts-plain 512 bits.