DS4243 or DS2246 ?

[mlorente1]

Hello, I have a question about expand FAS2040C, hope you can help me.

We have a FAS2050 which exports a volume of FC drives to a xenserver pool as an NFS storage repository, it contains the vhds of the Operative System of virtual machines. We have another SATA volume exported in the same way to the pool, but this one doesn't work due to its low performance, so it is intended for backups.

Due to the poor CPU of FAS2050, we need move the vm repository to the newer and faster FAS2040C, which is full populated with 15K disks, so we have to add an expansion shelf.

DS4243 allows 15K disks, which we know work fine for vm, but are quite more expensive than 10K drives, so we only can afford 10 disks of 450GB, on the other hand, DS2245 is smaller and cheaper, so we can afford 12 disk of 600GB or some more of 450GB, which allows more spindles, furthermore, this shelf works at 6Gbps instead of 3Gbps,like DS4243, but I  can't find any comparative chart for latencies or something similar, and we are worried about 10k disk and vm repositories.

Could you help me please?

[scottgelb]

The 15K drives are 3.5" form factor and the 10K drives in the DS2246 are 2.5" form factor... with the smaller form factor, the performance is very similar between the two.  For SAS, I prefer the DS2246 (love these shelves!) since they are fast, have a great form factor and use 2 PSUs instead of 4 PSUs on the larger shelf with SAS.

[radek_kubka]

Hi Scott,

with the smaller form factor, the performance is very similar between the two

Interesting. I remember this being pitched when 2.5'' 10k disks were first introduced (not on NetApp platform, in general). Despite that I tend to somewhat treat them as "slower brothers" of 3.5'' 15k drives (& effectively ignore).

Have you got any real-life performance comparison? And do you know whether NetApp sizing tools treat them more or less equally performance-wise?

Regards,
Radek

[scottgelb]

The spm sizing when I have compared the drives is roughy 80-85% of the performance.

Sent from my iPhone 5

[radek_kubka]

Just did sample VDI sizing on SPM - I'm getting 73% ratio (128x 3.5'' 15k spindles or 176x 2.5'' 10k ones)

[scottgelb]

I had a database one within 85%. Spm may handle differently.

Sent from my iPhone 5

[radek_kubka]

Sure thing - it is workload-dependent.

Well, either way 2.5'' option is a winner when physical density is concerned!

[scottgelb]

My favorite shelves cabling is easier with ioms left and right instead of top/bottom too.

Sent from my iPhone 5

[mlorente1]

nobody has performance measures of these shelfs or have tested before these disks for virtualization?