W dniu 12 lutego 2011 23:52 użytkownik Ric Wheeler
<rwheeler@xxxxxxxxxx> napisał:
> 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).
I re-enabled barriers on freshly created ext4.
>
> You can run "fs_mark -S 0 ...." to have it not issue the fsync() calls as
> well,
Ok, thanks for the tip. Problem with barriers appears only when I run
fs_mark without this option, during normal use I didn't noticed any
issues. It is interesting that now fs_mark shows two times more
files/sec
# fs_mark -S 0 -d test/
[..]
FSUse% Count Size Files/sec App Overhead
0 1000 51200 207.9 47442
>
> Ric
Thanks for your help!
>
>
>
>>> Drives can be noisy, but occasionally, if they are over noisy (you hear
>>> chattering when writing), it might just be a bad drive that has trouble
>>> settling the heads after a seek.
>>>
>>> You might want to check with:
>>>
>>> smartctl -a /dev/sda
>>>
>>> To look for errors that the drive reports.
>>
>> I regularly test all drives that I use, this one is irreproachable
>>
>> 1 Raw_Read_Error_Rate 0x002f 200 200 051 Pre-fail
>> Always - 0
>>
>> [..]
>>
>> Num Test_Description Status Remaining
>> LifeTime(hours) LBA_of_first_error
>> # 1 Extended offline Completed without error 00% 10
>> -
>>
>>
>>> Good luck!
>>>
>>> Ric
>>>
>>>
>> Thanks for your help!
>>
>
>
--
Best regards,
Michal
http://eventhorizon.pl/
--
devel mailing list
devel@xxxxxxxxxxxxxxxxxxxxxxx
https://admin.fedoraproject.org/mailman/listinfo/devel
