Re: [toaster] Syncdir

[Adam Woodbeck]

On 1/25/2005 3:31 PM, Rick Macdougall wrote: Bill Shupp wrote: Adam Woodbeck wrote: I've been running Matt Simerson's FreeBSD qmail toaster for several years now and I'm getting ready to build a linux toaster.  I've been warned of queue problems when running qmail under linux due to the way linux handles fsyncs.  I did some searching and found that if I included syncdir (http://untroubled.org/syncdir/) in my qmail build, fsyncs will be handled as qmail expects.  Is this still an issue because I do not see anywhere in the toaster setup where syncdir is linked in.  Thanks for your help. I'm not aware of any general fsync problems on Linux.  Anyone else had first hand problems with this? Hi, If I remember correctly, which I may not, there was a sync problem with one of the first releases of ReiserFS.  I don't believe there are any issues with any of the recent file systems. Google shows a lot of potential problems back in 2000/2001 ( http://oss.sgi.com/archives/linux-xfs/2001-05/msg00343.html ) but I don't see anything recent. Regards, Rick Here is the description of the issue I found: "Qmail was designed for BSD-like filesystems. And it is unreliable under Linux because it assumes that link() is a synchronous operation. This is not the case with EXT2 and ReiserFS. So you have to apply this patch to avoid losing messages due system crashes. You can run Qmail and ReiserFS without this patch, and never notice the bug, because you have to get a crash at the right time to trigger it. But according to Murphy's law, if your queue contains a highly important message, it will happen :)" I do not know if it is still relevant.  Our servers are on battery backups but we've strictly used qmail for our high volume mail servers running FreeBSD in production.  In any case, I was able to build qmail using the syncdir library and everything seemed to work just fine.  So better safe than sorry provided everything looks good after thorough testing. Adam