-1

We have server with hardware raid controller (Adaptec ASR71605Q). It has 10 sas HDD, 2 SSD for cache and 1gb onboard cache ram.

On server installed ESXi. On ESXi I'm start Linux, create 2Tb disk for tests. And now i need to test and ensure, that ssd-cache is really work. Adaptec utilities installed to ESXi (arcconf), but it's not clear is ssd-cache works or not.

I use fio to test iops with "direct=1" mode (that should work thru all caches directly with physical disks), and I get something around 1800 iops on 4k random writes with queue=32, that seems real 10 HDD speed.

Now i need perform some tests, that show, that ssd is work, but with all configuration I still get around 1800-2000 random iops. Which test on Linux can get me proof of ssd-caching?

easy_john
  • 3
  • 2
  • Have you given it time to actually cache some HDD data yet? it's not immediate usually, it's based on commonly-read/written sectors – Chopper3 Jan 23 '14 at 09:32
  • I try to do some writes, that should use cache, for example: create 50gb files with zeroes, then read this file. And in the end write and read speed is the same, as in configuration without ssd. – easy_john Jan 23 '14 at 11:25

1 Answers1

0

The RAID controller is able to gather statistics that show how the cache is used. You will need the arcconf command for this.

The following command should give you plenty of numbers that show how the cache is used:

arcconf GETLOGS 1 STATS tabular

Maybe you need to enable the statistics using the following command:

arcconf SETSTATSDATACOLLECTION 1 Enable
Oliver
  • 5,883
  • 23
  • 32