prentcorp
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12 'SAS' vs 24 'SATA' on DELL PowerVault MD3220i iSCSI SAN
Would having double the SATA drives provide realtively the same IOPS as the SAS Drives? We're looking to cluster a Hyper-v Environment with an Exchange 2010 vm and several database servers VM's. Below are more specifics on the drives we're looking at. We're just hoping someone else with some more experience can offer their suggestion. I'm not sure of the latency and cache, etc... on these drives. Our reasoning for thinking that the SATA drives would be nearly equal is because the qty of the drives is double (and cheaper) and with more drives to stripe to that the performance would be good.
In a RAID 60 Array...
24 x SATA 7.2K 500GB 6Gbp/s
-or-
12 x SAS 15k 600GB 6Gbp/s
In a RAID 60 Array...
24 x SATA 7.2K 500GB 6Gbp/s
-or-
12 x SAS 15k 600GB 6Gbp/s
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ASKER
Referring to your Intel link; is it possible that the SATA drives are "enterprise class"?
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There's a graph at http://www.dell.com/downloads/global/products/pvaul/en/powervault-md3200-nearline-sas.pdf which compares the near-line SAS with the equivalent SATA (they have the same HDA but different logic board). Both SATA and SAS flavours of the Baracuda ES.2 feature something called workload manager which if the drive gets hot puts it into read after write mode which really cripples performance but allows 24x7 operation. Without workload manager or a similar when they get hot they die quite quickly which is one reason why desktop drives aren't usable.
Assuming they aren't going to get hot then you will get about the same performance, perhaps a bit less since 7.2K disks are about 1/3 the IOPS of 15K SAS.
http://support.dell.com/support/edocs/systems/md3200i/en/matrix/matrix.pdf lists the supported drives, not the bit about having to buy from Dell or the MD3220 will refuse to play with them. (you can't even use ones with LSI or IBM firmware on even though the box is made by LSI logic.)
Assuming they aren't going to get hot then you will get about the same performance, perhaps a bit less since 7.2K disks are about 1/3 the IOPS of 15K SAS.
http://support.dell.com/support/edocs/systems/md3200i/en/matrix/matrix.pdf lists the supported drives, not the bit about having to buy from Dell or the MD3220 will refuse to play with them. (you can't even use ones with LSI or IBM firmware on even though the box is made by LSI logic.)
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I would rather go with a mix of :
-Good SSD (Crucial RealSSD, OCZ Vertex 2, Intel's) for IOPS intensive needs
-Enterprise class SATA 2.5" 500GB (Seagate Constellation, etc) for SPACE needs
Reading this Anandtech "SSD versus Enterprise SAS and SATA disks" article
http://www.anandtech.com/show/2739/11
you can expect 1x SSD to support the same IOPS than 12x SAS 15k drives
Budget:
-16x 500GB SATA drives : 16x $300 = $4800 for 4TB in RAID 10
-4x 256GB Crucial RealSSD C300 : 4x $550 = $2200 for 512GB in RAID 10
-Good SSD (Crucial RealSSD, OCZ Vertex 2, Intel's) for IOPS intensive needs
-Enterprise class SATA 2.5" 500GB (Seagate Constellation, etc) for SPACE needs
Reading this Anandtech "SSD versus Enterprise SAS and SATA disks" article
http://www.anandtech.com/show/2739/11
you can expect 1x SSD to support the same IOPS than 12x SAS 15k drives
Budget:
-16x 500GB SATA drives : 16x $300 = $4800 for 4TB in RAID 10
-4x 256GB Crucial RealSSD C300 : 4x $550 = $2200 for 512GB in RAID 10
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Pliant LB150S is an EFD (Enterprise Flash Drive) with very impressive features:
# IOPS: 120000
# Data throughput (read/write): >420/220 MB/s
# Full duplex, dual-port SAS interface
# Write cache-less design eliminates data loss on power interruptions
but the Dell price for it is going to be a non-sense as usual with Dell's drives
I thought that one was able to replace those unbelievably pricey Dell's drive by any other drives, isn't that possible or is it a service problem ?
# IOPS: 120000
# Data throughput (read/write): >420/220 MB/s
# Full duplex, dual-port SAS interface
# Write cache-less design eliminates data loss on power interruptions
but the Dell price for it is going to be a non-sense as usual with Dell's drives
I thought that one was able to replace those unbelievably pricey Dell's drive by any other drives, isn't that possible or is it a service problem ?
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MD3000 etc are OEM'd from LSI Logic and they key the firmware, you can't even put drives with LSI firmware in Dells, or Dell firmware drives in IBM enclosures etc and of course you can't flash them with the right firmware unless they are from the right vendor in the first place.
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Sorry about that...but, to my opinion, the discussion lead to valuable info that should be shared through EE.
"No solve" is an information as well...
You should PAQ the question instead of deleting it.
"No solve" is an information as well...
You should PAQ the question instead of deleting it.
ASKER
error correct/detection had not crossed our mind, any insight you can share on that?
Power/heat is not an issue.
We will be running load balanced gigabit ethernet using LACP and 4 independent connections between each controller, switch and server to provide roughly 4Gbp/s of bandwidth.
Best performance for read/write I'd say.