1 Reply Latest reply: Dec 23, 2013 2:33 PM by ASHWINPAWARTESL RSS

Raid group and Aggregate sizing

FRANMIGUEL Novice
Currently Being Moderated

Hi,

 

We are going to buy a FAS3220 extended IO, two controllers and

DS4246 - 24 or 22 1TB SATA 7.2k disks

2x DS2246 - 24 600GB SAS 10k disks

 

What would be the best distribution? one controller for SAS, the other one for SATA?

 

In SATA we are thinking of doing one of this options, since the give us the same data space:

- 2 rg 11 disk each one (9 data + 2 parity) + 2 spare

- 1 rg 20 disk (18 data + 2 parity) + 2 spare

 

What would give us the best performance? SATA will be used for NFS storage, with very big volumes.

 

I was trying to check with NetApp Synergy, but I seems to be already a client to use it, and at the moment we are IBM N-series users

 

Thank you very much

  • Re: Raid group and Aggregate sizing
    ASHWINPAWARTESL Cyclist
    Currently Being Moderated

    Hi,

     

    I would suggest having two smaller raid-groups for SATA with following raid-group size:

     

    RAID-DP:

    10 Data +2 Parity = 12 

    9 Data  +2 Parity = 11

                                       ----

                                      23

                                      -----

     

    One hot spare per controller should be just fine.

     

    Also by having two raid-groups in an aggregate rather than just one, has its own advantages when it comes to single whole-disk failure or double whole-disk failure. These are large capacity (1TB) drives, with slower spin rate(7200RPM) & seek time  and will take considerable time in rebuilding the spare disk from parity and even more time if you are putting all the disks in a single raid-group and hence the two smaller raid group serves better.

     

     

    As far as distribution is concerned, standard practice is to have all SAS on one head and all SATA on the other head.

     

    I hope this helps.

     

    Thanks,

    -Ashwin

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