2014-04-07 18:13 GMT+02:00 Evan Rowley <[email protected]>:
>
> I'd like to measure the total amount of data written over time to the
physical devices that make up zpool zils, l2arcs, and vdevs. Each one of
these physical devices has a projected Mean Time Before Failure (MTBF),
often measured in writes or data written to the device, which I'd like to
compare with the total number of writes to the device.
>
> The "zpool iostat" command can do this for a given period of time, but
unless I'm mistaken, it can't do this continually for an unpredictable
amount of time.
>
> I'm imagining that something like this can be done using dtrace, but I'm
not completley certain if that is the best way to tackle the problem.
>
> Are there any other ways to do this? (before i go re-inventing the wheel)
Many SSD:s keep SMART-accessible counters for data read and written;
[root@anto ~]# /opt/smartmontools/sbin/smartctl -d sat,12 -A
/dev/rdsk/c3t1d0p0
...
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED
WHEN_FAILED RAW_VALUE
...
241 Host_Writes_32MiB 0x0032 100 100 000 Old_age Always
- 355603
242 Host_Reads_32MiB 0x0032 100 100 000 Old_age Always
- 64535
Haven't seen the same on any spinning disks...
//jb
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