Stripe or Mirror or Both?

[Dan Matlock_1]

Hello All,

I have a small question? I have 10 disks in a array (believe its a 2405 model) with 2 FC connected to my rx2600 server. I am making this server a dedicated Ignite server with the 10 disk used for images only. I see disks down both fiber channels. No RAID, but would love to be able to loose a disk and not have the VG fail.
Best practice should be? Should I just stripe across the 10 and use alternate links down the other path. Should I somehow use HP-UX mirroring across the paths?
Any ideas would be great.

[Steven E. Protter]

Shalom Dan,

The answer is, it depends.

If you are doing a write intensive, database application, hardware raid 1 or software raid 1 mirroring is recommeneded.

If you wish to maximize disk space and read performance, a raid 5 setup with 10 disks is normally the best way to go.

SEP

[Pete Randall]

I would think that striping would increase the risks if you lose a disk. I would go with just mirroring.


Pete

[Dan Matlock_1]

Sorry, I guess I was not clear on what I have. I have a set of 10 disk in a model 2405, and NO Raid controller. I also have 2 x FC connected, so I see the same set of disks twice. If I have a RAID controller I'd just RAID 5 the think, but I can't. System is only my new Ignite server, so will be I/O bound if anything = non-production.
Maybe pvlinks and/or mirroring. I think I only have LVM to work with on this model: http://h20000.www2.hp.com/bizsupport/TechSupport/SupportTaskIndex.jsp?lang=en&cc=us&prodTypeId=12169&prodSeriesId=81150&taskId=115

[Geoff Wild]

You should do the striping/mirroring on the RAID - not on the OS.

Rgds...Geoff

[spex]

Dan,

You will need Mirrordisk/UX or something similar for software-based RAID:

http://h20293.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=B2491BA

Mirrordisk/UX retails for around $1k, and adds additional functionality to certain LVM commands.

Regardless of the RAID level you go with, make sure half of your disks are on one path, and half on the other. At a minimum, this will increase data throughput. You should also create pvlinks from disks on one controller to the mirrored disks on the other controller. This way you have basic failover capability, and eliminate a single point of failure.

PCS

[Dan Matlock_1]

thanks