[collectd] ZFS statistics

[Randy Bias]

Florian,


	Yes, that was a challenge for me as well.  I am not clear which of  
the ZFS information in kstat is actually useful.  I am hoping Dmitry  
can provide some insight.  For me, I was hoping that we could get per  
pool and per disk read and write IOPS.



--Randy



Randy Bias, chief tactician, neoTactics, Inc.
(877) NEO-TKTX, randyb at neotactics.com


On Jun 6, 2008, at 10:41 AM, Florian Forster wrote:

> Hi Randy,
>
> thanks again for getting me access to the NexentaOS and OpenSolaris
> machines :) Apparently ZFS statistics are available via kstat, which  
> is
> nice because that's already used by other plugins.
>
> Unfortunately I have no idea what the values mean or, more precisely,
> which ones are interesting. Is there some documentation what these
> values mean? Or, better yet, what they tell you ;)
>
> This one
> ---
> module: unix                            instance: 0
> name:   vopstats_zfs                    class:    misc
> ---
> looks a lot like the values the NFS plugin collects, i. e. number of
> opens, seeks, readdirs and so on. Also in there is `read_bytes' and
> `write_bytes' - I think this is definitely interesting. But what about
> `readdir_bytes'?
>
> This one
> ---
> module: unix                            instance: 0
> name:   zfs_znode_cache                 class:    kmem_cache
> ---
> I think is not that interesting, is it?
>
> The other two seem to hold quite detailed counters about a cache  
> which I
> guess is interesting. But there are so many numbers, I doubt that  
> all of
> them really matter.
>
> The relevant values provided by kstat are attached. If you find  
> anything
> exciting, let me know ;)
>
> Regards,
> -octo
> -- 
> Florian octo Forster
> Hacker in training
> GnuPG: 0x91523C3D
> http://verplant.org/
> <zfs.stats.txt>