RE: OFA and Shared Storage

Well, its beyond no "need" to multiplex - it rolls right into "might not be possible" (though that's an extreme case). Basically, since today's large arrays have several layers of abstraction between the storage consumer and the physical spindles, it can be difficult to determine what physical spindles data is living on.

>From a reliability standpoint, its always worthwhile to have extra copies of
things you need floating around, though in the case of a large array a fault that is severe enough to cause data loss at an array level is probably catastrophic enough to cause data loss on the copy(ies) as well. The more likely scenario is filesystem corruption when a server goes down.

Ask your storage administrator to work with you to put redolog copies on different RAID sets. If they look at you like you're crazy, get another storage administrator :) Or set up a meeting with your Large Storage Vendor - they have people on staff to help with things like that.

Thanks,
Matt

--
Matthew Zito
GridApp Systems
Email: mzito_at_gridapp.com
Cell: 646-220-3551
Phone: 212-358-8211 x 359
http://www.gridapp.com



> -----Original Message-----

> From: ml-errors_at_fatcity.com [mailto:ml-errors_at_fatcity.com] On 

> Behalf Of rgaffuri_at_cox.net

> Sent: Monday, September 22, 2003 2:05 PM

> To: Multiple recipients of list ORACLE-L

> Subject: OFA and Shared Storage

> 

> 

> I read some posts on here with shared storage such as SAN and 

> Network Appliances its no longer necessary to multiplex 

> datafiles on different disks, since the storage array handles 

> that for you. 

> 

> How do you ensure that control files and redo log files are 

> kept safely apart so that no one disk failure in the shared 

> storage can take them all out?

> 

> According to the OFA(well the abbreviated version I have in 

> front of me) 4-5 disks is optimal for multiplexing. Does this 

> no longer apply with shared storage? How do you ensure 

> database available with shared storage? if your not 

> multiplexing datafiles? 

> 

> I may have read some peoples posts incorrectly. Im just 

> digging into backup and recovery. 

> 

> -- 

> Please see the official ORACLE-L FAQ: http://www.orafaq.net

> -- 

> Author: <rgaffuri_at_cox.net

>   INET: rgaffuri_at_cox.net

> 

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