Re: Oracle performance - VSS vs. SSA

1. Er, I though VSS *was SSA*, just in different cabinets with different software management. Do you know different? If it is different, please let us know. Thanks.

The latest SSA adapters are RAID5 - called PCI SSA Multi-Initiator RAID5 adapter. I think these same cards are used in VSS, just like the same SSA drives are used. Again, if you find out different, let us know.

The testing I've done on RAID5 v striped disks (through LVM) shows the read rate to be the same. The write rate is *twice as slow*. That's RAID5 for you. You can improve things with the cache option for the SSA adapters, but it's not battery-backed, so I'd never use it with db's.

The current SSA adapters do not support RAID level 0 or 1. This is a pain. You can stripe with LVM, but you can't mirror striped disks at the same time via LVM. Still, you really want all this in the adapter anyway, IMO. Chase IBM up on this. Let me know what you find.

MotoX.

Chris Cummings wrote in message <35C0E66E.9457D70A_at_dsworks.com>...
>I have a client who is considering buying IBM's Versatile Storage
>Solution (VSS). VSS is based on Raid 5. The alternative is IBM's
>Serial Storage Architecture (SSA) using mirroring for high
>availability. Has anyone out there migrated a major Oracle OLTP system
>to VSS? If so was any change in performance detected? If anyone has
>conducted VSS performance testing, is there an I/O breakpoint at which
>performance begins to seriously degrade? Thanks in advance for any
>insight that you can give me.
>
>--
>Chris Cummings
>Dallas Softworks, Inc.
>
>chris_at_dsworks.com (214) 350-6085 Voice 2351 W. Northwest Hwy.
>http://www.dsworks.com (214) 769-4317 Cell Suite 2215
> (214) 351-2139 Fax Dallas, TX 75220
>
>
Received on Mon Aug 03 1998 - 02:48:53 CDT