spddemn
Contributor
Contributor

Looking at new ISCSI SAS vs SATA

Hello all,

We are looking to setup our large office on a SAN with about 4 physical hosts, we have about 1TB of usable data. I am looking between Dell Equal Logic PS5000E and Net App.

My question is any experience out there on SAS or SATA what seems to be better. Dell of course says SATA is fine on Equal logic, vs Net App quotes SAS.

0 Kudos
4 Replies
AntonVZhbankov
Immortal
Immortal

If you're not tight on budget choose SAS. SATA disks have better price for GB, while SAS have higher IOPS.

More VMs you're going to put on storage - more IOPS you need if you want smooth work.


---

VMware vExpert '2009

http://blog.vadmin.ru

EMCCAe, MCITP: SA+VA, VCP 3/4/5, VMware vExpert http://blog.vadmin.ru
0 Kudos
_VR_
Contributor
Contributor

I would look at the PS6000X (10K SAS) or the PS6000XV (15K SAS). I personally wouldn't use SATA for anything other than backups or archiving.

If you're looking to purchase all the software (exch/sql snapshot, replication, writable snapshots, etc) the EqualLogic will provide better value. A base NetApp system with SnapRestore will usually come out on top as far as price goes.

Also, there are a few gotchas with NetApp if you're planning to use it in an Active/Active HA configuration. The FAS2020 also doesn't have any expansion slots so you may want to look at the FAS2050 if you think you'll need aditional bandwidth capasitity in the future.

Bottom line is if you dont need the extra software licenses and can live with limitations of the unit, NetApp should be your choice.

0 Kudos
JohnADCO
Expert
Expert

I'm not that harsh on SATA, but we cheaped out some of our SANs with SATA and they work OK enough. Have no doubt we see notice-ably better performance on the same model SANs equipped with high rpm sas drives.

0 Kudos
_VR_
Contributor
Contributor

You're right John, in some configurations SATA will outperform SAS/FC.

For example, if you go with the NetApp FAS2020 Active/Active configuration it will most likely come with 12 15k SAS drives. The recommended configuration is to split the drives between two controllers so you have 6 drives for each. Then you loose 2 disks to parity and 1 disk as a spare. As a results you will have 2 agreggates with 525 ( 6-3=3, 3*175=525 ) read IOPS in each one.

With EqualLogic you will most likely go with the standard Raid 50 config. Two drives will be lost as spares and two will be used for parity. Unlike RAID-DP, RAID 5 disks aren't dedicated to parity giving you a total of 980 (16-2=14, 14*70=980) IOPS for the entire aggregate.

If you go with a single aggregate FAS2020 (single controller) for your NetApp you will get 1575 (12-3=9, 9*175=1575) IOPS.

IOPS asside there is still a question of SATA reliability compared to SAS/FC.

0 Kudos