It is completely accetable to bind parity (RAID5, 3, 6) and non-parity (RAID1, 1/0) across buses and enclosures. In fact binding RAID groups across two enclosures in separate buses will help with rebuild times. This is discussed in the document titled EMC CLARiiON Best Practices For Fibre Channel Storage. You can find this document in the documents section of this forum.
So if it doesn't bother you that your RAID 5 ggroup is split between enclosures then don't change it. There really is no need to.
I have always tried to keep a raid 5 configuration on the same DAE, it seems I ahve also read that using Raid 5 and crossing DAE's is not recommended.
The other question I have is most configuration for Exchange use Raid 1 and Raid 1/0 for the logs and DB's. I also believe that is a best practice not only with EMC but also Microsoft.
The EMC CLARiiON Best Practices for Performance and Availability, FLARE Revision 29 discusses this very question in the 'RAID group bus balancing' section. In addition, RAID group provisioning is discussed at a higher-level in the EMC CLARiiON Storage System Fundamentals. Both documents are available on Powerlink.
AranH1
2.2K Posts
0
June 22nd, 2010 11:00
It is completely accetable to bind parity (RAID5, 3, 6) and non-parity (RAID1, 1/0) across buses and enclosures. In fact binding RAID groups across two enclosures in separate buses will help with rebuild times. This is discussed in the document titled EMC CLARiiON Best Practices For Fibre Channel Storage. You can find this document in the documents section of this forum.
So if it doesn't bother you that your RAID 5 ggroup is split between enclosures then don't change it. There really is no need to.
llemau
2 Posts
0
June 22nd, 2010 08:00
We are migrating to Exchange 2010, they reduced the amount of disk IO. We have the DBs on RAID 5 and logs on RAID 1/0, still write intensive.
Bing59
1 Rookie
•
96 Posts
1
June 22nd, 2010 08:00
I have always tried to keep a raid 5 configuration on the same DAE, it seems I ahve also read that using Raid 5 and crossing DAE's is not recommended.
The other question I have is most configuration for Exchange use Raid 1 and Raid 1/0 for the logs and DB's. I also believe that is a best practice not only with EMC but also Microsoft.
Bing
bjpower
15 Posts
1
June 28th, 2010 04:00
It is best to keep RAID groups on the same bus.
If the RAID group is split between buses it can lead to issues.
spliting the RAID group between DAEs on the same bus will have little impact as they are on the same loop.
jps00
2 Intern
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392 Posts
1
June 28th, 2010 06:00
The EMC CLARiiON Best Practices for Performance and Availability, FLARE Revision 29 discusses this very question in the 'RAID group bus balancing' section. In addition, RAID group provisioning is discussed at a higher-level in the EMC CLARiiON Storage System Fundamentals. Both documents are available on Powerlink.