Hi, I use btrfs on most of my volumes on my laptop, and I''ve always felt booting was very slow, but definitely sure is slow, is starting up Google Chrome: encrypted ext4: ~20s btrfs: ~2:11s I have tried different things to find out exactly what is the issue, but haven''t quite found it yet. Here''s some stuff I got from latencytop, not sure if would be helpful: 4969.1ms sys_mmap_pgoff syscall_call (chrome) 1139.9ms sync_page sync_page_killable __lock_page_killable generic_file_aio_read do_sync_read vfs_read sys_read sysenter_do_call (chrome) 431.9ms sync_page wait_on_page_bit read_extent_buffer_pages btree_read_extent_buffer_pages read_tree_block read_block_for_search btrfs_search_slot lookup_inline_extent_backref __btrfs_free_extent run_clustered_refs btrfs_run_delayed_refs btrfs_commit_transaction (btrfs) Cheers. -- Felipe Contreras -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 2010-10-11 at 03:30 +0300, Felipe Contreras wrote:> Hi, > > I use btrfs on most of my volumes on my laptop, and I''ve always felt > booting was very slow, but definitely sure is slow, is starting up > Google Chrome: > > encrypted ext4: ~20s > btrfs: ~2:11s > > I have tried different things to find out exactly what is the issue, > but haven''t quite found it yet.If you''ve been using this volume for a while, it could just have become badly fragmented. You could try btrfs''s fancy online defragmentation abilities to see if that''ll give you an improvement: # btrfs filesystem defragment /mountpoint/of/volume Let us know if that helps, of course :) -- Calvin Walton <calvin.walton@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
I think I read/heard somewhere that snapshots can cause pretty bad fragmentation, because it causes your system to write changes to files to random locations on the disk, leaving the original inodes intact.. For that reason, I have replaced the directories ~/.config/chromium , /var , /usr/portage with subvolumes, so they will not be included in snapshots. It seems like chromium opens much quicker now, but it''s still a long way from what it was on ext4 On Mon, Oct 11, 2010 at 10:46 AM, Calvin Walton <calvin.walton@gmail.com> wrote:> > On Mon, 2010-10-11 at 03:30 +0300, Felipe Contreras wrote: > > Hi, > > > > I use btrfs on most of my volumes on my laptop, and I''ve always felt > > booting was very slow, but definitely sure is slow, is starting up > > Google Chrome: > > > > encrypted ext4: ~20s > > btrfs: ~2:11s > > > > I have tried different things to find out exactly what is the issue, > > but haven''t quite found it yet. > > If you''ve been using this volume for a while, it could just have become > badly fragmented. You could try btrfs''s fancy online defragmentation > abilities to see if that''ll give you an improvement: > > # btrfs filesystem defragment /mountpoint/of/volume > > Let us know if that helps, of course :) > > -- > Calvin Walton <calvin.walton@gmail.com> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Oct 11, 2010 at 7:23 PM, Chester <somethingsome2000@gmail.com> wrote:> I think I read/heard somewhere that snapshots can cause pretty bad > fragmentationBut I''m not using snapshots. -- Felipe Contreras -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Oct 11, 2010 at 6:46 PM, Calvin Walton <calvin.walton@gmail.com> wrote:> On Mon, 2010-10-11 at 03:30 +0300, Felipe Contreras wrote: >> I use btrfs on most of my volumes on my laptop, and I''ve always felt >> booting was very slow, but definitely sure is slow, is starting up >> Google Chrome: >> >> encrypted ext4: ~20s >> btrfs: ~2:11s >> >> I have tried different things to find out exactly what is the issue, >> but haven''t quite found it yet. > > If you''ve been using this volume for a while, it could just have become > badly fragmented. You could try btrfs''s fancy online defragmentation > abilities to see if that''ll give you an improvement: > > # btrfs filesystem defragment /mountpoint/of/volume > > Let us know if that helps, of course :)~2:06s, so it helped a bit, but not much really, there''s still something fishy going on. -- Felipe Contreras -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html