[TriLUG] Disk subsystem recommendations

[Ron Kelley]

In my experience, the spindle/head issue pretty much goes away using SSDs.  In addition, the Intel SSDs have the best IOPS of any consumer-grade SSDs (at least, according to my research).  I have personally tested the Intel SSDs using IOMeter and saw +20,000 IOPS using 512K reads - per drive.  Very fast indeed...


-Ron






On Nov 25, 2009, at 4:45 PM, Clay Stuckey wrote:

> The tricky thing is that there are several factors to disk performance. You have seek time (how much time it takes to find the data) then you have the read/write MB/s that is quoted. This is typically sequential read/writes. I expect you will have a mix of sequential and unordered read/writes in the real world.
> 
> While raid-0 does increase your transfer rate, you are still limited to a single spindle. This means your host OS and VM(s) will be fighting for head time. I have been running 3 fast sata drives in a raid0 for a while and have felt that I should have much better performance. That was until I realized that I can only get 1 piece of data at a time. I just recreated my volumes as 3 single drives. I have the host os on 1. The other 2 drives will each get a vm. I expect I will see a major performance increase for my situation.
> 
> If your host/guest machines are performing normal operations (ie: many small read/write operations), it would seem that seek time and separate spindles is what you need.
> 
> I don't know how solid state drives compare with platter drives. Maybe they can read/write more than one item at  a time.
> 
> I will let you know how my performance works out next week.
> 
> Clay
> 
> 
> 
> On Nov 25, 2009, at 4:36 PM, Ron Kelley wrote:
> 
>> x2 on the SSDs.  $489/ea for the Intel 160GB G2 SSDs (zipzoomfly.com).  Put a pair in RAID-0 for $1K.  Very fast and should last a long time.
>> 
>> -Ron
>> 
>> 
>> 
>> On Nov 25, 2009, at 4:31 PM, Joseph Tate wrote:
>> 
>>> I don't think you want the overhead of LVM.  I'd stick with straight partitions.
>>> 
>>> Why not go solid state disks?
>>> 
>>> On Tue, Nov 24, 2009 at 10:02 PM, btncix btncix <btncix at gmail.com> wrote:
>>>> I don't know much about VMWare nor much about virtualization, but if your
>>>> main concern is performance, I would suggest you keep RAID-0 and create
>>>> separate partitions. If you're worried about flexibility with hard drive
>>>> partitions, look into LVM for your root partitions and logical partitions
>>>> for your boot partitions. Of course, this more difficult to setup than what
>>>> you were thinking about, but it let's you keep RAID-0 and still create your
>>>> VMs with direct physical access to hard drive.
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>>>> 
>>> 
>>> 
>>> 
>>> -- 
>>> Joseph Tate
>>> Personal e-mail: jtate AT dragonstrider DOT com
>>> Web: http://www.dragonstrider.com
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>> 
>> Thanks,
>> 
>> -Ron
>> rkelleyrtp at gmail.com
>> 
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> 
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Thanks,

-Ron
rkelleyrtp at gmail.com