nickt
Contributor
- Joined
- Feb 27, 2015
- Messages
- 131
I'm sorry if this question has been asked before, but I can't see a clear answer. On my new RAIDZ2 FreeNAS box (6x 3TB disks), I've run an iostat for the first time (using the "Performance Test" button in the GUI). I've got the following results:
I'm quite surprised by how much lower the read speeds are than the write speeds? OK, the speeds are still fast enough to saturate a single GE link (which is all i've got), but why so low? Is this normal? I've run countless burnin tests and everything has come up good, so I don't anticipate any hardware issues.
Code:
Record Size 128 KB File size set to 41943040 KB Command line used: /usr/local/bin/iozone -r 128 -s 41943040k -i 0 -i 1 Output is in Kbytes/sec 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 41943040 128 474979 468843 138072 143652
I'm quite surprised by how much lower the read speeds are than the write speeds? OK, the speeds are still fast enough to saturate a single GE link (which is all i've got), but why so low? Is this normal? I've run countless burnin tests and everything has come up good, so I don't anticipate any hardware issues.