[zfs-discuss] Poor relative performance of SAS over SATA drives

2011-10-26 Thread weiliam.hong
Greetings, I have a fresh installation of OI151a: - SM X8DTH, 12GB RAM, LSI 9211-8i (latest IT-mode firmware) - pool_A : SG ES.2 Constellation (SAS) - pool_B : WD RE4 (SATA) - no settings in /etc/system *zpool status output* --- admin@openindiana:~# zpool status pool: pool_A

Re: [zfs-discuss] Poor relative performance of SAS over SATA drives

2011-10-27 Thread weiliam.hong
[mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of weiliam.hong 3. All 4 drives are connected to a single HBA, so I assume the mpt_sas driver is used. Are SAS and SATA drives handled differently ? If they're all on the same HBA, they may be all on the same bus. It may be *because* you're

Re: [zfs-discuss] Poor relative performance of SAS over SATA drives

2011-10-31 Thread weiliam.hong
Thanks for the reply. Some background.. The server is fresh installed. Right before running the tests, the pools are newly created. Some comments below On 10/31/2011 10:33 PM, Paul Kraus wrote: A couple points in line below ... On Wed, Oct 26, 2011 at 10:56 PM,

Re: [zfs-discuss] Poor relative performance of SAS over SATA drives

2011-10-31 Thread weiliam.hong
Thanks for the reply. On 11/1/2011 11:03 AM, Richard Elling wrote: On Oct 26, 2011, at 7:56 PM, weiliam.hong wrote: Questions: 1. Why does SG SAS drives degrade to10 MB/s while WD RE4 remain consistent at100MB/s after 10-15 min? 2. Why does SG SAS drive show only 70+ MB/s where