Did you see the iowait ? On Sun, Sep 25, 2011 at 2:13 PM, Marc Perkel <[email protected]> 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 >>> >>> >>> >> >> > -- > ## List details at > https://lists.exim.org/**mailman/listinfo/exim-users<https://lists.exim.org/mailman/listinfo/exim-users> > ## Exim details at http://www.exim.org/ > ## Please use the Wiki with this list - http://wiki.exim.org/ > -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
