first of all let me say changing providers isn't an option. That being said, I'm looking to possibly build up a machine for VPS (my initial thought is to use virtuozzo, although I've heard vmware is pretty good, and it's even free (yes, free as beer should be!) ) and the dilema is:
I can get obviously huge SATA drives (750) but these are only 7500rpm.. if I wish to move up to 10k well I'm down to 150GB (a raptor) and that's not much storage for a mchine being used as a VPS.. even with four fo those.
It simply doesn't get better.. so outside SATA, all drives are 75GB-150GB, but anywhere int he ranage of 10k-15k rpm, some even SCSI.
Should I bit my tongue and go with the smaller, SCSI drives? Or go for the space with the SATA drives? Implementing a SCSI solution for faster read/writes times is being considered, although I thought it would be useful to go for a RAID solution which also provides rendundency, therefore I would loose some storage space.
Any opinions in regards to best/prefered solution is welcome, thank you.
VPS generate a lot of random reads and somewhat less random writes. That assuming you have more than one on the machine.
Higher RPM and more disks will get you the best seek performance which rules random performance. To keep things within a budget, you generally sacrifice size to get more disks.
To a certain extent, if you over build RAM and use Linux (forget Windows for this tip - it doesn't work) you can skimp on disks and rely on the caching and buffering. At some point, though, you'll exceed the performance capabilities of the drives on a regular basis and that will no longer help. It only helps for bursts of disk activity that subside within a few minutes.
Your best performance is still going to come from 3.5" U320 SCSI disks. SAS is almost there, but the RAID controller features are still lacking when compared to the SCSI counterparts.
You can get 8 SATA II (NCQ) drives for the less than 4 Raptor or SCSI drives. At 7200rpm that is a lot more RPM (and space) for your dollar and more drives will provide better random seek/read. It's a little less than having 4 15k RPM drives.
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Benchmarks of the Raptor drives versus SCSI and SAS put it at a little less than half the performance of SAS and SCSI drives of the same RPM at high concurrency levels (multiple simultaneous requests). Same goes for SATA across the board. Web servers, databases, and VPS accounts all place high concurrency loads on disks.
If you're price/space conscious and aren't concerned with replacing disks frequently, go with SATA. "Everybody's doing it", he says in a high school impish 'you should follow the crowd' tone. ;-)
Disk vs. disk, dollar per year of life, dollars per concurrent seek, SCSI/SAS wins out every time. Billion dollar companies don't choose SATA for anything but nearline storage (aka stuff that doesn't get used much) and linear sequential access single threaded applications. They just don't.