The short answer is: YES
More channels = better I/O Performance.
But I must mention that there were a couple of comments on my choice of
RAID.
I already knew about the RAID 0+1 advantage of faster writes and offline
backups,
but.... as always, contracting with a poor State government, I'm at a
minimum of drives.
I'm lucky to have two SCSI channels.
So... my solution is going to be to have 1 RAID 0+1 Virtual Disk and two
RAID 5 sets.
RAID 5 uses less devices, and our particular database is 80% read anyway.
The RAID 0+1 VDisk will be used to hold the more write intensive Oracle
datafiles, such as TEMP.
Here is a page that covers the basic concepts of RAID and Oracle in general
( You can sub RAID 0+1 for RAID 1 ):
http://help.netscape.com/kb/corporate/19970930-3.html
> -----Original Message-----
> From: Sweatt, Wayne [SMTP:sweatt_at_dps.state.nm.us]
> Sent: Tuesday, September 12, 2000 4:16 PM
> To: DU Mail List
> Subject: RAID 5 across RA3000 channels a benefit?
>
> Dear DUrus,
>
> Before I configure my RAID 5 sets, on my RA3000, I thought to myself:
> Would it decrease latency and improve I/O performance of my Oracle DB
> if I configure my RAID 5 virtual disks across the two channels as opposed
> to one RAID 5 set per channel.
> I have a RA3000 with dual active/active controllers (HSZ22)
> at 64MB cache each.
> It's a direct match up between controller and shelf (and it's devices).
> Each of the two data channels is cabled to a BA356 exp. shelf.
> I was thinking that when Oracle reads/writes a datafile, that it would
> read/write the requested data faster if it were accessing striped data
> across the two channels ( less contention ).
> Yes, it's still a common SCSI channel (KZPBA) but getting data to/from
> disk media to/from controller cache would be faster across channels -
> right?
> Your thoughts on this please....
>
> Thanks,
>
> Wayne
Received on Wed Sep 13 2000 - 18:59:36 NZST