Re: ext2/3 vs xfs for maildir
On Fri, Jan 01, 2010 at 09:51:23AM -0600, Stan Hoeppner wrote: > Which filesystem is more appropriate for maildir use on a > Postfix/Dovecot system, ext2/3 or xfs? This maildir will be storing > mulitple mail folders and files, some folders containing over 10,000 > email files. I'd recommend XFS for two main reasons: 1. XFS does dynamic inode allocation, so you aren't wasting space for inodes you aren't using. You can tweak the number of inodes with ext, of course, but only at format time. 2. XFS handles large directories better, although setting dir_index might speed up your ext3 directory access quite a lot. Of course, XFS doesn't support full journaling, but you probably don't want that with such high mail volumes anyway. The maildir format is supposed to be atomic, but it's really up to the MTA/MDA to report successful delivery only after the file has been successfully written to disk, and may not work properly on NFS or other filesystems that don't support the proper semantics. The whole point of maildir, though, is to treat each email as an individual file, so this limits your damage even if you pull the plug in the middle of a write operation. That doesn't mean you can't lose data, but it sure is a lot harder to have a catastrophic failure that way. Maildir uses a lot of inodes, though, and this used to be a big issue for me back in the day when running qmail on ext2, because I had to configure the filesystem so it wouldn't run out of inodes before it ran out of disk space. These days, I think XFS is going to be more efficient, but with a big enough hard drive it probably won't matter enough to lose sleep over. > If xfs, what is the most appropriate mkfs.xfs command line for Unlike ext2/3, I find that the defaults for XFS work just fine. I typically add "relatime,barrier,logbufs=8" to the mount options, but I just use the default formatting options. This is definitely a YMMV situation, though. -- "Oh, look: rocks!" -- Doctor Who, "Destiny of the Daleks" -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Re: ext2/3 vs xfs for maildir
Volkan YAZICI wrote: > [...] ext2/3 requires huge amounts of rescan time during boot after > an unexpected reboot. Isn't the journal supposed to protect against this? IMO I don't see particularly long rescan times on the large-ish filesystem that I have (800 GB ext3 on lvm on top of hardware raid 5). What I do see is very slow disk access when using ext3 on lvm (approx 6 MB/s) - but I think that's a matter for another topic. Chris -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Re: ext2/3 vs xfs for maildir
On Fri, 1 Jan 2010, Stan Hoeppner wrote: Which filesystem is more appropriate for maildir use on a Postfix/Dovecot system, ext2/3 or xfs? This maildir will be storing mulitple mail folders and files, some folders containing over 10,000 email files. I'm a big fan of XFS and have successfully used it in high performance mail servers. If xfs, what is the most appropriate mkfs.xfs command line for creating the filesystem best tuned for the above described maildir? I have no previous Here are some general optimisations for high performance systems that I've put together: http://www.practicalsysadmin.com/wiki/index.php/XFS_optimisation Dovecot has a few words to say on the subject too. Search for XFS in the link below. http://wiki.dovecot.org/MailboxFormat/Maildir If you go with xfs then be sure to use xfsdump/xfsrestore for backups if you can. Cheers, Rob -- I tried to change the world but they had a no-return policy http://www.practicalsysadmin.com -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Re: ext2/3 vs xfs for maildir
On Fri, 1 Jan 2010, Volkan YAZICI wrote: I strongly agree, even in recent ext4 and nilfs benchmarks, reiserfs is generally the winner in many different scenarious. Besides, XFS is very disappointing at power failures and ext2/3 requires huge amounts of There are reasons for the observed XFS behaviour. If a file becomes corrupt XFS zeros the file rather than leaving a corrupt file in place. There are pros and cons to this approach. In any case it is essential to always keep good backups. Rob -- I tried to change the world but they had a no-return policy http://www.practicalsysadmin.com -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Re: ext2/3 vs xfs for maildir
On Fri, 1 Jan 2010, Camaleón writes: > On Fri, 01 Jan 2010 09:51:23 -0600, Stan Hoeppner wrote: >> Which filesystem is more appropriate for maildir use on a >> Postfix/Dovecot system, ext2/3 or xfs? This maildir will be storing >> mulitple mail folders and files, some folders containing over 10,000 >> email files. > > How about ReiserFS? > > Despite not being very much actively developed upstream, it is still a > very good filesystem, mainly for managing small files. I strongly agree, even in recent ext4 and nilfs benchmarks, reiserfs is generally the winner in many different scenarious. Besides, XFS is very disappointing at power failures and ext2/3 requires huge amounts of rescan time during boot after an unexpected reboot. Regards. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Re: ext2/3 vs xfs for maildir
On Fri, 01 Jan 2010 09:51:23 -0600, Stan Hoeppner wrote: > Which filesystem is more appropriate for maildir use on a > Postfix/Dovecot system, ext2/3 or xfs? This maildir will be storing > mulitple mail folders and files, some folders containing over 10,000 > email files. How about ReiserFS? Despite not being very much actively developed upstream, it is still a very good filesystem, mainly for managing small files. Greetings, -- Camaleón -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
ext2/3 vs xfs for maildir
Which filesystem is more appropriate for maildir use on a Postfix/Dovecot system, ext2/3 or xfs? This maildir will be storing mulitple mail folders and files, some folders containing over 10,000 email files. If xfs, what is the most appropriate mkfs.xfs command line for creating the filesystem best tuned for the above described maildir? I have no previous experience with xfs beyond reading about its superior performance for some workloads. Thanks much in advance. Happy new year all. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
