raw filesystem counters

[Ronald Klop]

On Mon, 12 Feb 2018 10:07:07 +0100, Andriy Gapon <avg at freebsd.org> wrote:

> On 12/02/2018 07:55, Peter Jeremy wrote:
>> On 2018-Feb-11 21:06:12 +0200, "E.S. Rosenberg" <esr at cs.huji.ac.il>  
>> wrote:
>>> Is there any way to access raw disk counters similar to those found on
>>> Linux in:
>>> /sys/class/block/<device>/stat
>>>
>>> Preferably also by accessing such a virtual file and not by using  
>>> iostat /
>>> zpool iostat which are already pre-processing counters and need to be  
>>> run
>>> constantly to get accurate real-time estimates.
>>
>> For the raw disk data, have a look at the statistics functions in
>> libgeom(3).  You can use the source code for gstat(8) to get a better  
>> idea
>> how to drive it.
>
> Or maybe devstat(3).

Or dtrace?


>> I don't know of any published API for vdev-level ZFS statistics and,
>> unfortunately, "zpool iostat" only supports "humanized" output, which  
>> makes
>> it difficult to use them as input to further monitoring.  There are some
>> ARC statistics under sysctl kstat.zfs.misc
>>
>