Of showers and sysstat
Posted: February 20, 2013 Filed under: NetApp, Storage | Tags: flash cache, netapp cpu %, netapp cpu utilization, netapp performance, performance, performance analysis, sysstat Leave a commentI was asked by a client yesterday in passing how to check CPU utilization on one of their NetApp filers. I didn’t immediately know where to go and we quickly moved on to something else. So as I was showering this morning, as I do many mornings, I remembered that, of course, you can use sysstat to view performance data. Anyways, this is a real nice way to view instantaneous general performance data. Options for this command are shown below.
deathstar> sysstat ?
usage: sysstat [-c count] [-s] [-u | -x | -m | -f | -i | -b] [interval]
-c count – the number of iterations to execute
-s – print out summary statistics when done
-u – print out utilization format instead
-x – print out all fields (overrides -u)
-m – print out multiprocessor statistics
-f – print out FCP target statistics
-i – print out iSCSI target statistics
-b – print out SAN statistics
interval – the interval between iterations in seconds, default is 15 seconds
So for a sample of utilization stats for 10 seconds, taken every second, we can use
deathstar> sysstat -i -c 10 -u 1
CPU Total Net kB/s Disk kB/s Tape kB/s Cache Cache CP CP Disk
ops/s in out read write read write age hit time ty util
1% 234 0 0 156 24 0 0 >60 99% 0% – 4%
0% 107 1 0 28 0 0 0 >60 100% 0% – 2%
1% 223 0 0 36 0 0 0 >60 100% 0% – 2%
1% 169 0 0 80 0 0 0 >60 98% 0% – 4%
7% 247 1 0 3856 4592 0 0 >60 100% 20% T 12%
2% 156 0 5 1952 32248 0 0 >60 99% 97% : 14%
1% 207 0 0 168 0 0 0 >60 99% 0% – 3%
1% 252 1 0 128 0 0 0 >60 99% 0% – 2%
1% 231 0 0 96 0 0 0 >60 99% 0% – 3%
1% 173 0 0 84 0 0 0 >60 100% 0% – 2%
On the far left we see CPU utilization, then total IOPS for all protocols, block and file and towards the right side we can see the Cache hit rate. This isn’t for Flash Cache, as I thought initially, but for memory cache hits. Flash Cache performance data can be gathered using a preset Flash Cache performance counter, seen here
deathstar> stats list presets
Stats Presets:
flexscale-access
flexscale-pcs
flexscale
spcres_aggr
spcres_vol
and
deathstar>stats show –p flexscale-access
This will spit out goodies such as cache usage %, hits/sec, misses/sec, and read and write chains.
An excellent article on performance monitoring of NetApp filers is right here…enjoy.