On 02/12/2011 11:52 PM, Ric Wheeler wrote: > On 02/12/2011 05:31 PM, Michał Piotrowski wrote: >> Hi, >> >> W dniu 12 lutego 2011 23:19 użytkownik Ric Wheeler >> <rwheeler@xxxxxxxxxx> napisał: >>> On 02/12/2011 05:12 PM, Michał Piotrowski wrote: >>>> Hi, >>>> >>>> I added a disc to my box. I wanted to use ext4. I run fs_mark to test >>>> speed, to my surprise I heard a really strange noises. >>>> >>>> It's very strange because the drive is new >>>> 9 Power_On_Hours 0x0032 100 100 000 Old_age >>>> Always - 12 >>>> >>>> >>>> # fs_mark -d test/ >>>> [..] >>>> FSUse% Count Size Files/sec App Overhead >>>> 0 1000 51200 22.8 54347 >>>> >>>> I decided to create an ext3 file system on this drive and everything works >>>> fine. >>>> >>>> # fs_mark -d test/ >>>> [..] >>>> FSUse% Count Size Files/sec App Overhead >>>> 0 1000 51200 103.7 57229 >>>> >>>> When I mount this ext3 fs as ext4 and run fs_mark I hear strange sounds >>>> again. >>>> >>>> I use F14 and self compiled kernel from rawhide 2.6.37-1.fc14.x86_64 + >>>> e2fsprogs-1.41.14-2.fc14.x86_64. >>>> >>>> I mount ecryptfs on top of this file system. >>>> >>>> Does anyone know what might be causing this strange ext4 behavior? >>>> >>> Hi Michael, >>> >>> fs_mark run a fsync heavy test. What you might be hearing is the impact of >>> the fsync's. ext4 defaults to using "write barriers" enabled, ext3 does not. >>> Without write barriers, those fsync push data from the box to the write >>> cache on the drive only. With barriers, the disk will flush that cache to >>> the platter, so the platter moves and you probably hear the head, etc. >>> >>> You can test if this is the cause by mouting ext4 with "nobarrier" to see if >>> the noise goes away. >> I mounted fs with nobarrier and now it works just like ext3. Thanks! This solves >> the riddle :) >> > > Good to hear that it worked! > > Note that the barrier code makes your data safer, so you should run with it on > by default (unless you really don't care about the file system). If ext3 was running fine without barriers for all these years why is this such a problem with ext4? Does ext4 do something differently that barriers are now required? Regards, Dennis -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
