Re: ZFS performance

From: Charles Sprickman <spork_at_bway.net>
Date: Fri, 16 Feb 2024 18:04:48 UTC

> On Feb 16, 2024, at 6:49 AM, Dimitry Andric <dim@FreeBSD.org> wrote:
> 
> On 16 Feb 2024, at 02:08, joe mcguckin <joe@via.net> wrote:
>> 
>> I have a ZFS fileserver running samba- I ‘m using it as a file server and as a Timemachine backup server. TM work but mit is really slow.
>> Are there speed tweaks for ZFS I can apply.  Does ZFS have perf monitoring features I can use to characterize the speed?
> 
> Apple's Time Machine is just horrendously slow in general, the host's
> file system does not seem to matter at all. If you just copy a regular
> file to that SMB share, you should see that it performs well enough.

Also not even sure I'd be poking at ZFS at all here - all the stuff I saw about improving TM performance has always focused on bizarre little tweaks to samba, not the underlying filesystem...

Charles

> 
> I am still unsure what it is in Time machine that makes it so slow, but
> it sometimes seems to stall completely on very small files, and it can
> take minutes (!) to copy just a few kilobytes.
> 
> It may help a little to do on the Mac:
> 
> sudo sysctl debug.lowpri_throttle_enabled=0
> 
> but it won't get significantly faster. People should complain to Apple,
> but they will probably just say that FreeBSD with Samba is not an
> officially supported use case. :)
> 
> -Dimitry
> 
>