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LVM & SAN question

 
Eric Ladner
Trusted Contributor

LVM & SAN question

I have to rp3410's connected to a VA7410 SAN and have AutoPath installed. Currently the Oracle database uses raw devices and ASM (using /dev/rdsk/c4t_d_ devices).

I thought since AutoPath was installed, it'd be better to create a VG & logical volume and use the "rlvol" charater device to take advantage of AutoPath instead of relying on just one path to the SAN. When configuring the VG, though, the second computer recognizes that the pysical disk (which is actually a shared SAN volume) is in use by another computer, but lets me go ahead and use it.

Would continuing down this path cause problems? Oracle (via ASM) is essentially managing all the I/O (although VxFS buffering might come in to play at this point and I don't have OnlineJFS installed).
2 REPLIES 2
Steven E. Protter
Exalted Contributor

Re: LVM & SAN question

Shalom,

I think system administrators are better at managing storage than Oracle ASM.

So long as both PATHS are valid, and nobody messes with the SAN I see no problem with your approach.

SAN setup matters here. A heavy write transaction database sitting on RAID 5 storage will have constant I/O bottlenecks. Better to put redo, data and index on storage configured for Raid 1 or 1/0 on the back end.

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Steven E Protter
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Denver Osborn
Honored Contributor

Re: LVM & SAN question

With AutoPath installed you wouldn't have to setup a VG and lvol for ASM to take advantage of AutoPath. AutoPath doesn't work at the LVM layer... If you didn't have AutoPath I could understand setting up a VG so you'd be able to use pv links.

Just configure ASM to use one of the device paths and you're set. AutoPath will take care of failover/back or load balance (depending on what you set) transparent to ASM.


-denver