Arch Linux

jyc

Member

From: Ithaca, NY

Registered: 2013-01-07

Posts: 8

[SOLVED] Slow initial starts/reads of programs on SSD w/ btrfs

Recently I have started to experience very slow initial starting and read times for all programs and files. I am running Arch Linux on an SSD with btrfs. I've tried changing mount options, changing schedulers, rebalancing btrfs, defragmenting, etc., but nothing seems to have helped at all. As an example, profile-sync-daemon takes 11 seconds to run on boot but less than half a second subsequently; even running ls takes 2 seconds before any output appears.

My /etc/fstab looks like so:

UUID=97d9bd80-f1ba-46c4-a1f1-639509bcc133 / 				btrfs	rw,noatime,discard,ssd,subvol=__active,compress=lzo,autodefrag,space_cache,inode_cache 0	0
UUID=97d9bd80-f1ba-46c4-a1f1-639509bcc133 /run/btrfs-root	btrfs	rw,noatime,discard,ssd,compress=lzo,autodefrag,space_cache,inode_cache 0	0
tmpfs	/tmp	tmpfs	nodev,nosuid	0	0
#UUID=1e608bf8-b8ef-4cde-aaaa-a2f4769b7838 none swap defaults,discard 0 

I've been tearing my hair out trying to fix this problem and think I'm going to go insane soon because for the life of me I can't find out why this is happening.

Any help would be seriously appreciated.

EDIT:

Here is the output of hdparm, which confuses me even more. I don't think ls is 1000MB big.

[jonathan@jc-t430-arch grub.d]$ sudo hdparm -tT /dev/sda
[sudo] password for jonathan: 

/dev/sda:
 Timing cached reads:   19266 MB in  2.00 seconds = 9643.05 MB/sec
 Timing buffered disk reads: 1558 MB in  3.00 seconds = 519.33 MB/sec

Last edited by jyc (2014-03-24 01:44:30)

jyc

Member

From: Ithaca, NY

Registered: 2013-01-07

Posts: 8

Re: [SOLVED] Slow initial starts/reads of programs on SSD w/ btrfs

... and after all that, I found out that the problem was due to settings I had applied on recommendation of "powertop". Disabling all of those "optimizations" turned out to fix it.