What I think you're asking is, "Can I create a MetaLUN with two components, one based on 1 TB SATA drives, and the other on 2 TB SATA drives?"
The answer to this question is "Yes", by using a concatenated MetaLUN.
The whitepaper EMC CLARiiON MetaLUNs: A Detailed Review explains how to do this and the implications. EMC CLARiiON MetaLUNs is downloadable from Powerlink.
It's possible, no worries there, but thinking of performance this might not be a good idea. Having said that, putting LUNs on SATAN isn't a good idea in the first place unless it's for streaming data, like video or backup or archived data.
I always calculate IOps per GB and whenever I create METALUNs I'll try to use RGs with comparable performance. So a RAID5 (41) RG using 146GB 15k disks gives you 5 x 180 = 900 IOps. If you carve out 1 large LUN this LUN has 900 IOps at it's disposal. If you now need a LUN twice as large but also twice the performance, you need a similar RG or a RG that has 900IOps available for the new METALUN component. This could come from a second RAID5 (41) 146GB15k RG which you completely use up or perhaps a RAID5 (9+1) 300GB15k RG which is now only 50% used (performance, not capacity).
jps00
2 Intern
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392 Posts
0
March 23rd, 2011 04:00
Well, technically a MetaLUN is only one LUN.
What I think you're asking is, "Can I create a MetaLUN with two components, one based on 1 TB SATA drives, and the other on 2 TB SATA drives?"
The answer to this question is "Yes", by using a concatenated MetaLUN.
The whitepaper EMC CLARiiON MetaLUNs: A Detailed Review explains how to do this and the implications. EMC CLARiiON MetaLUNs is downloadable from Powerlink.
RRR
4 Operator
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5.7K Posts
1
March 23rd, 2011 02:00
It's possible, no worries there, but thinking of performance this might not be a good idea. Having said that, putting LUNs on SATAN isn't a good idea in the first place unless it's for streaming data, like video or backup or archived data.
I always calculate IOps per GB and whenever I create METALUNs I'll try to use RGs with comparable performance. So a RAID5 (41) RG using 146GB 15k disks gives you 5 x 180 = 900 IOps. If you carve out 1 large LUN this LUN has 900 IOps at it's disposal. If you now need a LUN twice as large but also twice the performance, you need a similar RG or a RG that has 900IOps available for the new METALUN component. This could come from a second RAID5 (41) 146GB15k RG which you completely use up or perhaps a RAID5 (9+1) 300GB15k RG which is now only 50% used (performance, not capacity).
Does this make any sence ?
douglas_carson2
21 Posts
0
March 23rd, 2011 06:00
Thanks guys for the posts.
I have managed to convince the client to take a different tact to no meta LUNs required.
Cheers
Dougie