On Fri, Jul 03, 2009 at 11:53:07AM +0100, Nick Lunt wrote: > > I'm running Oracle 10g on RHEL5, using Equallogic iSCSI SAN. Works > like > > a > > charm, no problems at all. > > > > What kind of iSCSI storage are you using? > > > > Have you benchmarked your iSCSI LUNs? What kind of performance do you > > get > > with other software than Oracle? > > > > -- Pasi > > Hi Pasi > > were using a Dell MD3000i with 300GB 15K SAS disks on RAID1. > 2 x 1GB NIC's on the server and a Dell 5448 1GB switch with a vlan > dedicated to iscsi. >
So you're using only 2 disks for the Oracle LUN? Each 15K SAS disk can do around 300 random IOPS max.. so with RAID1 you can get max 300 IOPS for writes, and max 600 IOPS for reads. Is that enough for your workload? (I'm assuming controller cache doesn't give you much help when you have random-IO patterns..) 600 IOPS * 4kB per request == 2400 kB/sec == 2,34 MB/sec. For comparison our Equallogics have 14 or 16 disks in RAID-10, and the LUNs split across all the disks. > We can't do any benchmarking as the system is 24x7. > > Running a sequential dd to the iscsi storage bypassing the cache I can > get over 70MB/s. > It seems that the small random I/O of Oracle is not performing over > iscsi (for us anyway). > > What I/O do you get ? > Sequential throughput is around 112 MB/sec using one gigabit connection and large blocksizes. -- Pasi _______________________________________________ rhelv5-list mailing list [email protected] https://www.redhat.com/mailman/listinfo/rhelv5-list
