2016-07-07 06:38 PM
2-node FAS8040 with flash cache running in clustered ontap 8.3GA with 10GbE ports.
From a Linux client with single 10GbE connection, I ran several tests using iozone to obtain write/rewrite and read/reread performance numbers for an NFS mounted volume on NetApp. I notice all runs produce reads much less than writes. As an example,
kB reclen write rewrite read reread random read random write
8388608 4 2774799 2079447 111926 4616036 3701496 2193816
8388608 8 2963944 3444805 111376 5532988 5025833 2742466
8388608 16 3227913 3766890 110325 5083604 5953205 3247727
Notice for all record lengths, reads are in ~100MB/sec while writes are much higher, 2.7 - 3GB/sec.
1. I question the numbers for writes in the range of 3GB/sec which is excessively high even over 10Gbps link.
2. the 'read' numbers are way smaller than writes which does not make sense to me.
Could someone shed some lights on what I've missed?