I am not sure about this concept. I want to know that if I have a storage pool of raid R5(4+1) with 50 X 600 Gb SAS drives in pool ?
What would be the best BIG and Small sized lun for that pool ?
Specially, when I am considering the THINK lun.
Please help on that ...
It's recommended that you limit the number of Luns per pool, because as the number of LUNs increases, it becomes more difficult to predict or determine if the i/o is complementary or contentious without time-comsuming analysis and debug.
The performance of LUNs depends on the performance of the underlying RAID groups. In a virtual pool with more than one thick LUN, LUNs share the underlying RAID group's IOPS and bandwidth. Increasing the capacity of the LUN within its current virtual pool or traditional RAID group does not improve its performance.
But my question is different. I want to know that if I have a Pool of R5(4+1) with 50 X 600 gb SAS drives ,then in that case...
Which sized lun would give me best performance .. ???
Since you have created a 4+1 RAID5 RAID group using SAS drives for this pool, that means the performance of LUN can be calculated. It is no matter how big LUN is, the maximum theoretical IOPS of any LUN in this pool is:
SAS 10k 4(drive numbers)×140=560
SAS 15K 4(drive numbers)×180=720
According to the document "VNX best practice for performance", SAS 10K disk can provide 140 IOPS, SAS 15K disk can provide 180 IOPS.
I'd recommend that you review a couple of documents. These provide the basis of creating and designing your array for best performance. There is an art to getting your array to run the best you can, so these documents provide the basics for this.
If you intend to use Databases in the future, then you should also review the SQL/Oracle White Papers. If you're going to be using Exchange, there are white papers for that also.
Go to EMC.SUPPROT.COM for finding the White Papers.
Go to mydocuments.emc.com for creating custom documentation for connecting your hosts.