NAS RAID level

[bmwisme]

I have a small budget for a NAS for backup storage - single ESXi 5 host w/5 VMs at the moment. I have tried VeeamZIP (purchase coming) to local storage (single SATA II drive datastore, not to array) and got approx. 80-90 MBps.

1) What would be the best RAID level to use for backup storage?
2) What can I expect for throughput over gigabit x 2?

I was just planning on CIFS but the devices I am considering also support NFS and iSCSI.

QNAP TS-419U
Synology RS812

Need 1U as I an renting rack space. Either unit with 8TB (4 x 2TB) Enterprise SATA II drives will hit my budget of $1500.

Thanks

[Gostev]

RAID10 is best if you can afford, as it provides smallest hit on write IOPS. Otherwise, RAID5.

[bmwisme]

RAID10 is best if you can afford, as it provides smallest hit on write IOPS. Otherwise, RAID5.

Thanks Gostev. I will only have a 4 drive NAS and would prefer to have a hot spare (or 2 failure protection). I realize the best would be RAID 10 best thought I could get away with RAID 1, 5, or 6. I also wasn't sure if the a current generation low end NAS (1.6 to 2.0 GHz) will have enough processing power to support RAID 5 or 6 without a bottleneck. Totally I am only backing up 200-300 GB, much less with compression and incremental.

[dellock6]

Hum, on that kind of NAS (iomega, qnap, synology) raid10 is best also because the CPU maybe has not enough power to manage efficiently the parity needed for raid5 or 6, while on raid10 there is no parity to be calculated. Since you only need that amount of space, you can buy 4 * 2 Tb disks, have a total space of 4 Tb and save on it a long retention...

Luca.

[J1mbo]

Also recommend RAID-10, buy a fifth disk and keep it on-site for quick swap when needed. The problem with RAID-5 is not just the CPU, but a random write has a 4-IO cost so with 3 drives... it just can't perform well.