MSA1500 + 2 X MSA30 SCSI

[Potterkop]

I need to expand our existing msa1500 with a new msa30 cabinet containing 15K 300GB scsi disks.

The old msa30 contains 10K 300GB disks.

I need to divide the storage between 3 hosts. These hosts are connected via FC.

The MSA1500 has two active/active controllers but has only one IO module which connects to the msa30. The new cabinet has a dual channel scsi IO module.

What should I do :

Divide the cabinets over two IO modules on MSA1500 (need to buy another IO module) or connect trough the dual channel msa30 ?

If I create the volumes should i divide the mirrors on both cabinets and the raid6 only on on cabinet. In case of powerfailure at least the raid6 stays consistent ?

Every advice is welcome.

Thanks in advance

[Martin Smoral]

IF you bought a dual bus MSA30 cab with 2 scsi connectors on it, then you have 2 options:
1) you need 2 more MSA1500 I/O modules and connect one to each MSA30 port.
2) buy a single bus I/O module for the MSA30 and buy 1 MSA1500 I/O module and connect them together.

Option 1 would be better since you will then be utilizing 3 SCSI buses for I/O instead of 2. I would create your arrays across the SCSI Buses, then create you R1, R5 or R6 Logicals

[Potterkop]

Thanks you for your reply !

So the more IO Modules the better ?

Is it wise to devide the disks between the 2 cabinets ? If a powerfailure occurs i will loose my RAID6 ? or better to place every RAID6 on each msa30 ?

Thanks in advance

[Greybeard]

Hi, for disk I/O spreading across both MSA30s is better, the main bottleneck with RAID 6 is at the controller due to extra parity calculations. The PSUs in the shelves are redundant so if you use seperate feeds the power outage scenario should be unlikely. Oh and if you only connect one cable to a single port on the dual port module you will only see half of your disks as this module splits the bus on the enclosure.

[Potterkop]

Thanks for your reply,

So i resume :

Buy 2 IO modules for the msa1500.

Is it wise to buy a third io module and a dual io module for the existing msa30 ?

Then the performance is devided between 4 io-modules?

hanks in advance.