On 21-8-2017 15:23, Mark Martinec wrote: > 2017-08-21 14:47 Willem Jan Withagen wrote: >> In the amavis rc.d file is noted: >> "========================================================" >> "WARNING: using ramdisk is reported to be unstable and" >> "thus it is highly recommended to be turned off." >> "========================================================" >> >> And this warning seems there since 2012.... >> >> Is this warning still valid? >> And if YES, could somebody try and enlighten me as to what is unstable >> on this config? >> - Is the ramdisk itself unstable? >> - Or is it the fact that upon a crash de ramdisk is lost and email >> might be lost? > > I don't really know what was the reason for this warning, but I can > guess that it's because the port creates a mdmfs ram disk of a fixed > size for the %%AMAVISDIR%%/tmp file system, and any fixed size small > disk may eventually run out of space, either during some peak mail > traffic rush-in, of perhaps when soma stale temporary files happen > to be left undeleted and accumulating, while this goes unnoticed > for some time.
Oke, so these are the regular sysadmin troubles of a (too) small a disk. Nothing a good purge can not fix.... Full disk might indeed lead to a sort of DOS situation. > Using tmpfs instead of mdmfs could avoid some of the above concerns > if you really want to use a ram disk. In my experience with a > modern host and file systems, especially with SSD, there is no longer > any substantial speedup by using a ram disk instead, so I don't > think it is worth sacrificing memory for a ram disk, which could > better be used by file system caches etc. 'mmmm this system runs in VM on KVM in OpenStack. And one of the bottlenecks is amavis flushing all mail to a disk. And that pushes the virtual disk to their limit. Switching some ramdisk on really does help in the load. >> - Or is it the fact that upon a crash de ramdisk is lost and email >> might be lost? > > No, mail should not be lost. Write failures would be noticed and > a feeding mailer would receive a temporary failure (smtp status 450), > so mail should stay in the mailer's queue for a later retry. > But left unattended for days, this would result in mail non-delivery > notification to the sender. Right. As far as I know will postfix only note amavis complete if Amavis has really reported as such, and only then tkae the file from the waiting queue. So a crash would not result in wrong deliveries. So perhaps the wording on that message should be less strong and prohibitive? --WjW _______________________________________________ freebsd-ports@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-ports To unsubscribe, send any mail to "freebsd-ports-unsubscr...@freebsd.org"