29.09.2011 20:54, Fabricio Archanjo пишет:
> Did you see the iowait ?
>
While running bonnie++:
Linux 2.6.32-5-686 (debian) 30.09.2011 _i686_ (2 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0,04 0,00 0,38 5,87 0,00 93,71
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
cciss/c0d1 5,13 412,87 788,02 37377072 71338512
> On Sun, Sep 25, 2011 at 2:13 PM, Marc Perkel<marc@???> wrote:
>
>> If you just have 45 gigs of data who not go with SSD drives? SSD is really
>> fast.
>>
>>
>> On 9/23/2011 1:13 AM, Andrey wrote:
>>
>>> 23.09.2011 11:31, Janne Pikkarainen пишет:
>>> Thank you for reply,
>>>
>>> BTW, other webserver has almost the same bonnie results (10283ms and
>>> 5884ms) on ext3 partition with 45GB of data (1.5 millions of files)?!
>>>
>>> Hardware and RAID5(also hardware) are the same: HP Proliant DL380 G4 with
>>> SmartArray 6i controller (as I see it comes with 128MB BBWC enabler but not
>>> kit).
>>>
>>> I did not tried to mount fs with barriers disabled. Does it have any
>>> crititcal risks?
>>>
>>> Bonnie tests was performed in the morning when we have a mininmal user
>>> load.
>>>
>>> With regards, Andrey.
>>>
>>> Hello,
>>>>
>>>> On 09/23/2011 08:51 AM, Andrey wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> I have a production mail server with maildir++ structure and about
>>>>> 250GB (~10 millions) of files on the ext3 partition on RAID5. It's
>>>>> mounted with noatime option. These mail server is responsible to local
>>>>> delivery and storing mail messages.
>>>>>
>>>>> System has Debian Squeeze installed and Exim as MDA + Dovecot as
>>>>> IMAP+POP3 server.
>>>>>
>>>>> Bonnie results are terrible. Sequential output for Block and Rewrite
>>>>> are 10722ms and 9232ms. So if there is a 1000 messages in the mail
>>>>> queue load is extremely high, delivery time is very big and server can
>>>>> hang. I did not see such problems with UFS on FreeBSD server.
>>>>>
>>>>> As I understand ext3 file system is really bad for such configurations
>>>>> with Maildir++ (many smaill files)? Is there a way to decrease disk
>>>>> latency on ext3 or speed up it?
>>>>>
>>>>> With regards, Andrey
>>>>>
>>>>> ___
>>>>>
>>>>
>>>> (replying off-list, so the ext3 developers will not start a flamewar)
>>>>
>>>> In my opinion ext3 is a terrible file system for your kind of workload,
>>>> especially if you have lots of concurrent clients accessing their
>>>> mailboxes. Even though ext3 has evolved over the years and has gained
>>>> features such as directory indexes, it still is not good for tens of
>>>> million of frequently changing small files with lots of concurrency.
>>>> Been there, done that, not gonna do it again. I administer servers with
>>>> 50 000 - 100 000 user accounts, with couple of thousands active IMAP
>>>> connections.
>>>>
>>>> Personally I switched from ext3 to ReiserFS many years ago and happily
>>>> used it between 2004-2008, then after things went downhill from ReiserFS
>>>> development point of view, I switched to XFS during a server hardware
>>>> refresh. ReiserFS was excellent, but it really started to slow down if
>>>> file system was more than 85% full and it also got fragmented over time.
>>>>
>>>> XFS has been rock-solid and fast since 2008 for me, but it has an
>>>> achilles heel of its own: if I need to remove lots of files from a huge
>>>> directory tree, the delete performance is quite sucky compared to other
>>>> file systems. This has been improved in the later kernel versions with
>>>> the new delaylog parameter, but how much, I've not yet tested.
>>>>
>>>> All this said, the performance of ext3 should not be THAT bad you are
>>>> describing. Is the bonnie result done while the server is idle or while
>>>> it has mail clients accessing it all the time? If you have hardware
>>>> RAID, is there a battery-backed up write cache and are you sure it's
>>>> enabled? Also, have you tried to mount your file system with barriers
>>>> disabled? What kind of server setup you have?
>>>>
>>>> Something is very wrong.
>>>>
>>>> Best regards,
>>>>
>>>> Janne Pikkarainen
>>>>
>>>>
>>>>
>>>
>>>
>> --
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