SATA Shelves in Metrocluster in 3140 with FC Shelves

[dbutxaca]

Currently we have installed a FAS 3140 + Stretch metrocluster with 2 shelves with 300 GB FC drives.

Now we want to add 2 more shelves and we thought about buying SATA shelves/disks but do not know if they are compatible with the current configuration.

Will metrocluster work properly with SATA shelves/disks ?

Do we need some conversor or additional hardware in order to make it work ?

Thank you  !

DBG

[aborzenkov]

SATA shelves are supported in stretch MetroCluster. Rules are the same – SATA and FC must be on different loops. Check MC support matrix on NOW for more information.

[dbutxaca]

Thank you for your answer.

Do you know since SATA drives in DS14 shelves and stretch metrocluster are suported ? It's new on 2011 or it is supported since long time ago ?

DBG

[paulstringfellow]

Certainly been on there a year, that’s when I did our first customer metrocluster

Don’t know how much earlier than that though.

[pascalduk]

Supported at least since ontap 7.2.5, which means mid/end 2008.

[peter_lehmann]

Answers here:

http://communities.netapp.com/message/45340#45340

[paulstringfellow]

Hi,

They will work fine…

Have a customer install with a 3240 and FC and SATA drives connected up…

No problem at all…

[dbutxaca]

Thank you very much. We apreciate your answer. Our provider insists that we need some very expensive switch to use SATA disks and insists that we must install FC disks instead. Event they offer 600 GB shelves/disks at the price of 300 GB.

I guess they are not interested in selling SATA disks. Witch can be the difference between one SATA 1GB disks shelve and one FC 300GB or 600 GB disks shelve ?

We don't understant this behavior. Actually we have a FAS3140 stretch MC with 2 DS14 on each controller, 300 GB disks.

[pascalduk]

Other than capacity the obvious difference between a SATA and FC disk is performance. A SATA drive can do a lot less (random) IOPS than FC and has a higher read latencies.

You should only use SATA when your data has ver low IOPS requirements and you need to store a lot of it. In my environment I use it for file shares that require the high availability of metrocluster but don't have IOPS requirements.

[dbutxaca]

Exactly ! That's also our idea. We work in a Hospital. We put Oracle Databases, VM, SQL Server Databases, ... in FC shelves and want to put File Shares, Medical documents, DICOM Studies, ... in a SATA shelves.

We are aware that performance is lower than FC disks, but enough.

Thats wy we don't understant provider's behaivor. Maybe remaining stocks ?

DBG

[paulstringfellow]

Wouldn’t like to say! ☺

In terms of performance, there are plenty of guides and tools to check that the SATA disks will give the relevant IOPS for your workloads.

Good luck… couple of other users pointed you in the direction of the metrocluster guides, so use them to point your supplier in the right direction, they may still have good reason to suggest FC only, but at least you have all the information at hand.

[paulstringfellow]

Without knowing all the details of your setup I wouldn’t question your provider on here…

All I’d say is that SATA drivers are supported and work fine in a metrocluster environment without the need for any additional hardware, they are no different than the fibre shelves in terms of MC setup.

As pointed out here, then SATA drives are slower speed higher capacity, so if you need high IOPS throughput then FC is the way….unless you are going to put a flashcache card in front of the SATA drives, which will give performance and capacity, but does depend on the workload to get the full benefit.

Hope that helps

Paul.