Secondary HD problem

[dibl]

Re: Secondary HD problem

Meh. For reasons that are beyond me, my debian sid 2.6.37 kernel is not doing anything at all with the "compress" and "space_cache" mount options -- they do not show up in the output of the "mount" command, after I have added them to /etc/fstab, and enabled them with "mount -a". I ran my little file transfer timing test, to be sure, and there is zero difference before and after enabling the options. So, I think I'm suffering from "early-adopteritis" on this one.

Hmmmm. I wonder if I can install Natty on a VM, using a btrfs filesystem ......

[oshunluvr]

Re: Secondary HD problem

dmesg should show

[230344.699298] btrfs: enabling disk space caching
[230344.699304] btrfs: forcing compression

[dibl]

Re: Secondary HD problem

Hmmmmmmmmmmmmmmmmm.

Yeah, you are correct oshunluvr:

[  16.122047] btrfs: use compression
[  16.122049] btrfs: enabling disk space caching

and, moreover, after rebooting "mount" now shows:

devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
/dev/sde on /mnt/DATA type btrfs (rw,device=/dev/sdd,device=/dev/sde,compress,space_cache)
/dev/sdc1 on /mnt/REVODATA type ext4 (rw,nosuid,nodev,noatime,commit=300)

so, I guess the answer is, it requires a system reboot to actually take effect -- "mount -a" is not sufficient.

Interesting!

And THANKS!

[oshunluvr]

Re: Secondary HD problem

Did your speed pick up at all?

[dibl]

Re: Secondary HD problem

We're about 15 minutes from knowing the answer to that!

[dibl]

Re: Secondary HD problem

Well, here are the measured results -- read 'em and weep:

BTRFS Copy Speed Test

Without space_cache and compress options
Large File From To Time
1 ext4 btrfs 1:33
2 btrfs ext4 3:54
Small Files
1 ext4 btrfs 0:04
2 btrfs ext4 0:01

With space_cache and compress options
Large File From To Time
1 ext4 btrfs 1:52
2 btrfs ext4 3:48
Small Files
1 ext4 btrfs 0:04
2 btrfs ext4 0:01



Large file is a 16.3GB video (.mp3)

Small files is a directory with 2,485 small files and 50 sub-directories, total size about 320MB.

Nothing that will change anyone's life, so far.