Re: Which FileSystem do you use on your postfix server?
DULMANDAKH Sukhbaatar пишет: For me XFS seemed very fast. But usually I use ext3, which is proven to be stable enough for most situations. I feel also that xfs if much faster than ext3 and reiserfs, especially when it deals with metadata. In some bulk operation (bulk changing attributes of ~10 files) it was approx. 15 times faster than ext3 (20 sec xfs, 5 min ext3). xfs's journal covers only metadata, so you probally lose some lastest not-synched data on power loss, but you will stay with consistent fs.
Re: Which FileSystem do you use on your postfix server?
Wietse Venema wrote: Bryan Irvine: How long ago was that? I had the precise problem and had been told that particular bug has been fixed. My problems were ~5 years ago. Except that I'm never going to use it anyway because I just can't force myself to trust it. I've used Postfix under ext3, ffs(openbsd), ufs(solaris) and never had a single problem with any of them. ext3 gets the bonus for being (I think) the only one of those to be journaled. I suggest using the simplest file system that gets the job done, keeping in mind that Postfix presents a write-mostly load that is dominated by metadata. FLASH memory drives are beginning to look more and more attractive. BTW Solaris UFS has had journaling support as of Solaris 7. Wietse Yes it has, and its quite solid now, on Solaris 10 I would go for ZFS, if you want options for Solaris there is QFS (expensive) and VxFS (free up to four filesystems) /Johan A
Re: Which FileSystem do you use on your postfix server?
Nikita Kipriyanov: DULMANDAKH Sukhbaatar ?: For me XFS seemed very fast. But usually I use ext3, which is proven to be stable enough for most situations. I feel also that xfs if much faster than ext3 and reiserfs, especially when it deals with metadata. In some bulk operation (bulk changing attributes of ~10 files) it was approx. 15 times faster than ext3 (20 sec xfs, 5 min ext3). xfs's journal covers only metadata, so you probally lose some lastest not-synched data on power loss, but you will stay with consistent fs. Does XFS still overwrite existing files with zeros, when those files were open for write at the time of unclean shutdown? This would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail. Wietse To: Private List [EMAIL PROTECTED] From: Theodore Ts'o [EMAIL PROTECTED] Date: Sun, 19 Dec 2004 23:10:09 -0500 Subject: Re: [evals] ext3 vs reiser with quotas [...] This issue is completely different from the XFS issue of zero'ing all open files on an unclean shutdown, of course. [..] The reason why it is done is to avoid a potential security problem, where a file could be left with someone else's data. Ext3 solves this problem by delaying the journal commit until the data blocks are written, as opposed to trashing all open files. Again, it's a solution which can impact performance, but at least in my opinion, for a filesystem, performace is Job #2. Making sure you don't lose data is Job #1.
Re: Which FileSystem do you use on your postfix server?
On Fri, 31 Oct 2008, Wietse Venema wrote: Does XFS still overwrite existing files with zeros, when those files were open for write at the time of unclean shutdown? This I believe this was fixed in an early 2.6.2x release, cc'ing xfs mailing list to confirm. would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail.
Re: Which FileSystem do you use on your postfix server?
Justin Piszcz: On Fri, 31 Oct 2008, Wietse Venema wrote: Does XFS still overwrite existing files with zeros, when those files were open for write at the time of unclean shutdown? This I believe this was fixed in an early 2.6.2x release, cc'ing xfs mailing list to confirm. would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail. If there is a response you may want to repost it here (with permission) because submissions from non-members are silently discarded here. Wietse
Re: Which FileSystem do you use on your postfix server?
On Fri, 31 Oct 2008, Wietse Venema wrote: Justin Piszcz: On Fri, 31 Oct 2008, Wietse Venema wrote: Does XFS still overwrite existing files with zeros, when those files were open for write at the time of unclean shutdown? This I believe this was fixed in an early 2.6.2x release, cc'ing xfs mailing list to confirm. would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail. If there is a response you may want to repost it here (with permission) because submissions from non-members are silently discarded here. Found it (fixed on May 8th 2008): http://oss.sgi.com/projects/xfs/faq.html#nulls Q: Why do I see binary NULLS in some files after recovery when I unplugged the power? Update: This issue has been addressed with a CVS fix on the 29th March 2007 and merged into mainline on 8th May 2007 for 2.6.22-rc1. XFS journals metadata updates, not data updates. After a crash you are supposed to get a consistent filesystem which looks like the state sometime shortly before the crash, NOT what the in memory image looked like the instant before the crash. Since XFS does not write data out immediately unless you tell it to with fsync, an O_SYNC or O_DIRECT open (the same is true of other filesystems), you are looking at an inode which was flushed out, but whose data was not. Typically you'll find that the inode is not taking any space since all it has is a size but no extents allocated (try examining the file with the xfs_bmap(8) command). -- Justin.
Re: Which FileSystem do you use on your postfix server?
On Fri, 31 Oct 2008, Wietse Venema wrote: would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail. If there is a response you may want to repost it here (with permission) because submissions from non-members are silently discarded here. http://oss.sgi.com/projects/xfs/faq.html#nulls Since XFS does not write data out immediately unless you tell it to with fsync, an O_SYNC or O_DIRECT open (the same is true of other filesystems), you are looking at an inode which was flushed out, but whose data was not. Typically you'll find that the inode is not taking any space since all it has is a size but no extents allocated (try examining the file with the xfs_bmap(8) command). I also searched for this. Every place said that xfs may lose data if fsync() wasn't done, but nobody says that xfs will definitely keep data if fsync() was done, the basic requirement of Postfix
Re: Which FileSystem do you use on your postfix server?
Eric Sandeen: This would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail. As long as postfix is looking after data properly with fsyncs etc, xfs should be perfectly safe w.r.t. data integrity on a crash. If you see any other behavior, it's a *bug* which should be reported, and I'm sure it would be fixed. As far as I know, though, there is no issue here. The specific question is, will unclean shutdown cause loss of data that was already fsynced, when the file was updated after the fsync. For example, if the on-disk file metadata is updated after the file data is appended, then there is no need to have a zero-fill problem after crash during append. What if the crash happens after Postfix requests a 1-byte write in the middle of a file, i.e. without changing the size? A reasonable implementation would not corrupt the file, but would either update the file data or not change it. I can deal with that. Wietse
Re: Which FileSystem do you use on your postfix server?
Dave Chinner: On Fri, Oct 31, 2008 at 11:37:58AM -0400, Wietse Venema wrote: Eric Sandeen: This would violate a basic requirement of Postfix (don't lose data after fsync). Postfix updates existing files all the time: it updates queue files as it marks recipients as done, and it updates mailbox files as it appends mail. As long as postfix is looking after data properly with fsyncs etc, xfs should be perfectly safe w.r.t. data integrity on a crash. If you see any other behavior, it's a *bug* which should be reported, and I'm sure it would be fixed. As far as I know, though, there is no issue here. The specific question is, will unclean shutdown cause loss of data that was already fsynced, No. when the file was updated after the fsync. and no. XFS guarantees that you won't lose anything you fsync()d. You might lose what you wrote after the fsync()), though, because you haven't fsync()d it. Obvious, yes? This is how I hoped any reasonable implementation would work. The stories about null files made me wonder if there was something unusual about XFS that I should be aware of. For example, if the on-disk file metadata is updated after the file data is appended, then there is no need to have a zero-fill problem after crash during append. In case you didn't read Eric's response - that's exactly how we fixed XFS to prevent this problem. And please stop propagating this erroneous zero-fill meme - Eric addressed how wrong that FUD is as well. Just confirming a specific case that I care about. Here's something I would like to know regarding the order of directory updates: - Does fsync(file) guarantee the file's directory entry is safe? Some file systems complete directory updates before the open/link/rename system call returns, so fsync() doesn't have to worry about it. - Does rename() guarantee that at least one directory entry will exist even when the system crashes in the middle of the operation? Postfix assumes both answers are yes; old ext2fs violated both assumptions. What if the crash happens after Postfix requests a 1-byte write in the middle of a file, i.e. without changing the size? A reasonable implementation would not corrupt the file, but would either update the file data or not change it. I can deal with that. That is exactly how XFS has always behaved for non-extending data overwrite. i.e. Exactly the same pretty much every filesystem that has ever existed. Good. Thanks for confirming that XFS is not unusual. Wietse
Re: Which FileSystem do you use on your postfix server?
Charles Marcus ha scritto: On 10/29/2008, Joe Sloan ([EMAIL PROTECTED]) wrote: All our production boxes are 100% reiserfs, and have been for some years, based on performance testing. They have been rock solid, and most of them have 800 day uptimes at this point. I did some performance comparisons a few months ago and reiser still has a large lead over ext3. As reiser has always been the default filesystem on suse enterprise linux, it stands to reason that it has been well vetted. I'd have to say 'me too' here, although I only use it for our maildirs... My understanding is reiserfs' big weak point is unclean shutdowns, which can be minimized/eliminated by using good UPS's and hardware RAID cards with battery backup for the cache... Mine survived one unclean shutdown (extended power outage in the middle of the night) with no problems... I've also hear people who have had nightmares with ext3... No filesystem is perfect. No filesystem is perfect, that's certainty so. BTW thank's for these answers as well, the decision will not be easy and I'll make some tests as well. Bye Simon
Re: Which FileSystem do you use on your postfix server?
On Thu, Oct 30, 2008 at 03:53:30PM +0100, Simone Felici wrote: I've also hear people who have had nightmares with ext3... No filesystem is perfect. No filesystem is perfect, that's certainty so. Sure, no filesystem exhibits *optimal* performance under all work-loads, but in terms of data integrity, I expect and demand *perfection*. Perhaps no Linux filesystem is mature/stable enough to meet this standard, but do not accept less than perfect data integrity from your filesystem: - Barring memory corruption, or I/O bus errors, ... the filesystem is always recoverable at boot time and no files changes committed with fsync() are lost. - Boot time recovery rolls incomplete operations forward or back as appropriate, and brings the filesystem into a consistent state. Past reports of ReiserFS on this list indicate that it falls short of reasonable (i.e. perfect) data integrity expectations. -- Viktor. Disclaimer: off-list followups get on-list replies or get ignored. Please do not ignore the Reply-To header. To unsubscribe from the postfix-users list, visit http://www.postfix.org/lists.html or click the link below: mailto:[EMAIL PROTECTED] If my response solves your problem, the best way to thank me is to not send an it worked, thanks follow-up. If you must respond, please put It worked, thanks in the Subject so I can delete these quickly.
Re: Which FileSystem do you use on your postfix server?
On Oct 29, 2008, at 1:29 AM, Simone Felici wrote: I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: /var/spool/postfix AND the partition that will contain all mails in MailDir format. At the moment the server has ~100.000 mailboxes and more or less 120.000 mails stored per day (already filtered trought spam filters from frontend servers). I had similar volumes at my last job admining mail for a University. I ended up keeping /var/spool/postfix on a NetApp (WaffleFS is SOLID, but hideously expensive) and mounting it from several boxes to distribute load-- if budget constraints are tight you might investigate ZFS depending on what your OS restrictions are. Feel free to contact me off-list if you'd like me to go into more detail about what I did to avoid NFS write locks, etc...
Re: Which FileSystem do you use on your postfix server?
On Thu, Oct 30, 2008 at 10:09:46AM -0700, Jay Chandler wrote: I would create the system on EXT3 (RHES) and the following partitions on rieserfs: /var/spool/postfix AND the partition that will contain all mails in MailDir format. At the moment the server has ~100.000 mailboxes and more or less 120.000 mails stored per day (already filtered trought spam filters from frontend servers). I had similar volumes at my last job admining mail for a University. I ended up keeping /var/spool/postfix on a NetApp (WaffleFS is SOLID, but hideously expensive) and mounting it from several boxes to distribute load-- if budget constraints are tight you might investigate ZFS depending on what your OS restrictions are. Mounting user maildirs via NFS is supported, mounting the Postfix queue directory via NFS is not a good idea, and is NOT supported. NFS does NOT deliver the requisite unix filesystem semantics on which Postfix relies. Mail will be lost under adverse (networking) conditions. Keep the Postfix queue_directory local. -- Viktor. Disclaimer: off-list followups get on-list replies or get ignored. Please do not ignore the Reply-To header. To unsubscribe from the postfix-users list, visit http://www.postfix.org/lists.html or click the link below: mailto:[EMAIL PROTECTED] If my response solves your problem, the best way to thank me is to not send an it worked, thanks follow-up. If you must respond, please put It worked, thanks in the Subject so I can delete these quickly.
Re: Which FileSystem do you use on your postfix server?
Joe Sloan wrote: Ralf Hildebrandt wrote: * Simone Felici [EMAIL PROTECTED]: Hi Postfix-Users! I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: I would never use reiserfs for anything except our disposable Squid Cache. Stay with ext3, it works. But ext3 does have problems - All our production boxes are 100% reiserfs, and have been for some years, based on performance testing. They have been rock solid, and most of them have 800 day uptimes at this point. I did some performance comparisons a few months ago and reiser still has a large lead over ext3. As reiser has always been the default filesystem on suse enterprise linux, it stands to reason that it has been well vetted. Of course, the legal woes of the reiserfs creator have put the future of the filesystem in doubt. The future seems to be btrfs. ext4 might be a good stepping stone along the way, when it's ready, but if I had to pick a filesystem to deploy today, it would be reiserfs - xfs could get some consideration as well, but we just really don't want the performance hit that comes with ext3. Joe But it also is one of the most used and tested file systems for Linux. We also used reiserfs under Suse and had so many problems with it in an iscsi SAN environment. I can remember 2-3 full 6 hour recoveries had to be done with lost data as the prize in the end and this for the mailserver only. We had several servers with fs corruption to the point I preached against using reiserfs and they finally listened. Switched to ext3, on all servers which I wanted to do for years, and haven't had an issue yet except one fsck that was performed and it did not loose data. Even if you want the fastest filesystem for your needs, what is the true bandwidth you are seeing currently? What is your iowait? I bet it isn't really isn't that much overall where reiserfs vs ext3 vs whatever will make a huge improvement. Thanks, Randy Ramsdell
Re: Which FileSystem do you use on your postfix server?
On Thu, Oct 30, 2008 at 10:47 AM, Randy [EMAIL PROTECTED] wrote: Joe Sloan wrote: Ralf Hildebrandt wrote: * Simone Felici [EMAIL PROTECTED]: Hi Postfix-Users! I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: I would never use reiserfs for anything except our disposable Squid Cache. Stay with ext3, it works. But ext3 does have problems - All our production boxes are 100% reiserfs, and have been for some years, based on performance testing. They have been rock solid, and most of them have 800 day uptimes at this point. I did some performance comparisons a few months ago and reiser still has a large lead over ext3. As reiser has always been the default filesystem on suse enterprise linux, it stands to reason that it has been well vetted. Of course, the legal woes of the reiserfs creator have put the future of the filesystem in doubt. The future seems to be btrfs. ext4 might be a good stepping stone along the way, when it's ready, but if I had to pick a filesystem to deploy today, it would be reiserfs - xfs could get some consideration as well, but we just really don't want the performance hit that comes with ext3. Joe But it also is one of the most used and tested file systems for Linux. We also used reiserfs under Suse and had so many problems with it in an iscsi SAN environment. I can remember 2-3 full 6 hour recoveries had to be done with lost data as the prize in the end and this for the mailserver only. We had several servers with fs corruption to the point I preached against using reiserfs and they finally listened. Switched to ext3, on all servers which I wanted to do for years, and haven't had an issue yet except one fsck that was performed and it did not loose data. Even if you want the fastest filesystem for your needs, what is the true bandwidth you are seeing currently? What is your iowait? I bet it isn't really isn't that much overall where reiserfs vs ext3 vs whatever will make a huge improvement. How long ago was that? I had the precise problem and had been told that particular bug has been fixed. My problems were ~5 years ago. Except that I'm never going to use it anyway because I just can't force myself to trust it. I've used Postfix under ext3, ffs(openbsd), ufs(solaris) and never had a single problem with any of them. ext3 gets the bonus for being (I think) the only one of those to be journaled. -B
Re: Which FileSystem do you use on your postfix server?
Bryan Irvine: How long ago was that? I had the precise problem and had been told that particular bug has been fixed. My problems were ~5 years ago. Except that I'm never going to use it anyway because I just can't force myself to trust it. I've used Postfix under ext3, ffs(openbsd), ufs(solaris) and never had a single problem with any of them. ext3 gets the bonus for being (I think) the only one of those to be journaled. I suggest using the simplest file system that gets the job done, keeping in mind that Postfix presents a write-mostly load that is dominated by metadata. FLASH memory drives are beginning to look more and more attractive. BTW Solaris UFS has had journaling support as of Solaris 7. Wietse
Re: Which FileSystem do you use on your postfix server?
Victor Duchovni wrote, at 10/30/2008 12:44 PM: Past reports of ReiserFS on this list indicate that it falls short of reasonable (i.e. perfect) data integrity expectations. I also value data integrity over performance and will add that XFS never made it out of my punishment closet into a production system. On Linux, I use ext3 and have never lost data, even in the worst of conditions.
Re: Which FileSystem do you use on your postfix server?
Victor Duchovni wrote: On Thu, Oct 30, 2008 at 03:53:30PM +0100, Simone Felici wrote: I've also hear people who have had nightmares with ext3... No filesystem is perfect. No filesystem is perfect, that's certainty so. Sure, no filesystem exhibits *optimal* performance under all work-loads, but in terms of data integrity, I expect and demand *perfection*. Perhaps no Linux filesystem is mature/stable enough to meet this standard, but do not accept less than perfect data integrity from your filesystem: - Barring memory corruption, or I/O bus errors, ... the filesystem is always recoverable at boot time and no files changes committed with fsync() are lost. - Boot time recovery rolls incomplete operations forward or back as appropriate, and brings the filesystem into a consistent state. Past reports of ReiserFS on this list indicate that it falls short of reasonable (i.e. perfect) data integrity expectations. Disk hardware failures, early kernel bugs, vendor issues, all could be reasons for such reports. I did see some reiserfs problems some years ago under redhat, but that was an old 2.4 kernel, redhat didn't officially support reiserfs, and it's no longer relevant IMHO. I will say this much: reiserfs, as shipped in suse enterprise linux, on a 2.6 kernel, has performed flawlessly in our data center, running with lots of disk I/O on a 24/7 basis. We have had power outages, but have never lost a single bit on reiserfs Joe
Re: Which FileSystem do you use on your postfix server?
On Oct 30, 2008, at 10:18 AM, Victor Duchovni wrote: Mounting user maildirs via NFS is supported, mounting the P Doh, my error. You are of course correct-- this was in a pre-maildir environment, so /var/mail was mounted via NFS; the moving parts for Postfix lived on FreeBSD's UFS. --Jay
Re: Which FileSystem do you use on your postfix server?
For me XFS seemed very fast. But usually I use ext3, which is proven to be stable enough for most situations. -- Regards Dulmandakh
Re: Which FileSystem do you use on your postfix server?
* Simone Felici [EMAIL PROTECTED]: Hi Postfix-Users! I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: I would never use reiserfs for anything except our disposable Squid Cache. Stay with ext3, it works. -- Ralf Hildebrandt ([EMAIL PROTECTED]) [EMAIL PROTECTED] Postfix - Einrichtung, Betrieb und Wartung Tel. +49 (0)30-450 570-155 http://www.arschkrebs.de I'm looking for a job Given the opacity of the product, how could a Windows admin ever know as much about Windows as a UNIX admin does about UNIX?! (Roger B. A. Klorese on Postfix Mailing List)
Re: Which FileSystem do you use on your postfix server?
I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: I would never use reiserfs for anything except our disposable Squid Cache. Stay with ext3, it works. Ditto. Unless your mail volume is pretty extreme it is hard to believe you'll see performance difference of filesystems; if your I/O is slow your disk / controller are a much more source of the problem.
Re: Which FileSystem do you use on your postfix server?
* Simone Felici [EMAIL PROTECTED] wrote: I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: /var/spool/postfix AND the partition that will contain all mails in MailDir format. Postfix works perfectly with it's spool on an ext3 filesystem - or rather, the list of Linux specific issues at http://www.postfix.org/LINUX_README.html does not mention ext3. Given this and the fact that a lot of people are running Postfix with it's spool on an ext3 filesystem suggests that there are no fundamental problems with this setup (well, there is one gotcha: At least on i386, ext3 can only handle 32k inodes per directory). Since some point during development of the 2.4 kernel, ext3 got the ability to use htree hashing for direcotry indexing. I don't know whether the Orlov allocator ever made it to the official kernel, but nevertheless, an ext3 filesystem initialized for storing a lot of small files (inode_ratio = 4096) and htree inidces (-O dir_index) is perfectly capable of dealing with the requirements that mail handling imposes. That said, although I personally never had any issues with ReiserFS, there are really tons of problem reports out there on the net - so I'd never use ReiserFS for any data I care for - though it might be perfectly fine for things like a proxy cache. Besides, I never saw any real performance gains (see below). At the moment the server has ~100.000 mailboxes and more or less 120.000 mails stored per day (already filtered trought spam filters from frontend servers). If directory access times really become an issue, you can always work around that: The configuration parameter virtual_mailbox_maps allows you to store incoming mail in a directory structure of several levels instead of a flat hierarchy. For example: [EMAIL PROTECTED] - $virtual_mailbox_base/incertum.invalid/cite could also become [EMAIL PROTECTED] - $virtual_mailbox_base/i/incertum.net/c/cite We cannot give you any advice on a possible way to organize your mail storage without knowing some real data on the number of domains and localparts per domain involved. Any suggestions? Any test results on both FS to compare with mine I'll create? Back in 2004, during my time at university, me and some friends performed some quick tests, which you can find at: http://tinyurl.com/6bb3q4 It's in German, but perhaps you can find an online service to translate it - though I seriously doubt it's worth the trouble: Old kernel and we didn't really put that much effort into the tests we performed. There are a number of performance related docs in the Postfix website: http://www.postfix.org/TUNING_README.html http://www.postfix.org/QSHAPE_README.html As a last remark: IMAP servers typically impose a greater I/O load on a system than the MTA itself. There are massive performance differences betweens Cyrus, Courier, uw-imapd and Dovecot, so perhaps you might want to search for a benchmark on those programs. Conclusion: Don't put valuable data on ReiserFS. Don't do premature optimization. You can always change filesystems if your tests show performance gains and you run into performance shortages. Cheers Stefan -- Stefan Förster http://www.incertum.net/ Public Key: 0xBBE2A9E9
Re: Which FileSystem do you use on your postfix server?
Stefan Förster ha scritto: Conclusion: Don't put valuable data on ReiserFS. Don't do premature optimization. You can always change filesystems if your tests show performance gains and you run into performance shortages. Cheers Stefan Thank you for the answer, I'll take a look to your tests too, no problem for German language (lebe in Südtirol, hier deutsch muss man kennen ;) ) Also now I've a good point to start migration and tests on the server with more or less 1000 domains. Mopst of them with some mails, only a few domains with more than thousend mailboxes. Nice work will be the migration of the old server (qmail and mails stored in maildir format). Byebye simon
Re: Which FileSystem do you use on your postfix server?
Ralf Hildebrandt wrote: * Simone Felici [EMAIL PROTECTED]: Hi Postfix-Users! I know, there is enough written on the net and on the mailinglist too, but have found only old results, maybe the meanwhile something is different, also I would ask you... Which filesystem do you use on your mailserver? I'm going to migrate a mailserver with EXT3 (and qmail) to a new postfix mailserver (virtual domains on mysql, ...). I would create the system on EXT3 (RHES) and the following partitions on rieserfs: I would never use reiserfs for anything except our disposable Squid Cache. Stay with ext3, it works. But ext3 does have problems - All our production boxes are 100% reiserfs, and have been for some years, based on performance testing. They have been rock solid, and most of them have 800 day uptimes at this point. I did some performance comparisons a few months ago and reiser still has a large lead over ext3. As reiser has always been the default filesystem on suse enterprise linux, it stands to reason that it has been well vetted. Of course, the legal woes of the reiserfs creator have put the future of the filesystem in doubt. The future seems to be btrfs. ext4 might be a good stepping stone along the way, when it's ready, but if I had to pick a filesystem to deploy today, it would be reiserfs - xfs could get some consideration as well, but we just really don't want the performance hit that comes with ext3. Joe
Re: Which FileSystem do you use on your postfix server?
On 10/29/2008, Joe Sloan ([EMAIL PROTECTED]) wrote: All our production boxes are 100% reiserfs, and have been for some years, based on performance testing. They have been rock solid, and most of them have 800 day uptimes at this point. I did some performance comparisons a few months ago and reiser still has a large lead over ext3. As reiser has always been the default filesystem on suse enterprise linux, it stands to reason that it has been well vetted. I'd have to say 'me too' here, although I only use it for our maildirs... My understanding is reiserfs' big weak point is unclean shutdowns, which can be minimized/eliminated by using good UPS's and hardware RAID cards with battery backup for the cache... Mine survived one unclean shutdown (extended power outage in the middle of the night) with no problems... I've also hear people who have had nightmares with ext3... No filesystem is perfect. -- Best regards, Charles
