Re: ZFS performance

Van: Dimitry Andric <dim@FreeBSD.org>
Datum: vrijdag, 16 februari 2024 12:49
Aan: joe mcguckin <joe@via.net>
CC: freebsd-fs <freebsd-fs@freebsd.org>
Onderwerp: Re: ZFS performance
> 
> 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.
> 
> 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
> 
>  
> 
> 
> 


Just a me-too message, but I have my Mac syncing with TM over Samba (on Truenas) over WiFi pretty well. It uses ZFS mirror on 2 consumer grade SATA  disks.
The speed can fluctuate a lot but it just runs in the background anyway. Only the first sync takes a while and I don't remember if that can resume from being interrupted or not.

NB: my previous TrueNAS had a 100mbit network card which could get saturated so much that it couldn't even do DNS requests anymore which broke starting other backup streams. Current machine has 1gbit which has enough bandwidth for all leftover traffic,
What I want to say is that the details matter here. Look at the system and try to find the bottleneck.

Regards,
Ronald.