How to interpret iozone values
- by Henno
I ran a test to measure my I/O IOPS on Linux:
iozone -s 4g -r 2k -r 4k -r 8k -r 16k -r 32k -O -b /tmp/results.xls
iozone claims that output is in operations per second yet the numbers are too big for that to be plausible. I'm observing some 320 CMDs/s maximum on vmware esx console (esxtop, then v).
File size set to 4194304 KB
Record Size 2 KB
Record Size 4 KB
Record Size 8 KB
Record Size 16 KB
Record Size 32 KB
OPS Mode. Output is in operations per second.
Command line used: iozone -s 4g -r 2k -r 4k -r 8k -r 16k -r 32k -O -b tmpresults.xls
Time Resolution = 0.000001 seconds.
Processor cache size set to 1024 Kbytes.
Processor cache line size set to 32 bytes.
File stride size set to 17 * record size.
random random bkwd record stride
KB reclen write rewrite read reread read write read rewrite read fwrite frewrite fread freread
4194304 2 19025 5580 27581 29848 284 198 415 1103217 1498 18541 4340 24245 25618
4194304 4 15650 21942 18962 21068 252 1198 193 976164 1677 22802 23093 21089 21232
4194304 8 11121 11638 10273 10165 247 1196 202 625020^C
The test ran for 15 hours before I pressed ^C. Is that ordinary expectation for such command line (dedicated 4 drive RAID10 LUN, 10k RPM SAS drives in EMC CX300)?