Re: Optimal Storage Server
On 7/23/2012 7:42 AM, Shaffin Bhanji wrote:
> Thank you Stan!
>
>> Just imagine what it would do if you started from scratch with 20 of the
>> Black drives in md/RAID6 w/a 32K chunk, and XFS tuned to the stripe.
>> You'd easily hit 1GB/s streaming reads, with streaming writes probably
>>> 500MB/s. Depends on your CPU. I forgot which one is in the Asus board.
>
> Now this is the system I want to put together 1GB/s streaming reads,
> and 500MB/s writes - please recommend the hardware for me to the tee
> as I dont want to go wrong anywhere :-)
That's not what you want. Don't confuse peak sequential throughput with
random throughput. Your workload is almost entirely random IO. The
configuration I describe above is absolutely unsuitable for a random IO
workload. Ramon's primary application is video streaming, and his
secondary is moving/copying large video files. These are purely
sequential workloads. The above system is suitable for his needs, not
yours.
Your primary workload is serving virtual machine disk files as iSCSI
LUNs, and Samba shares. This workload is dominated by random, not
sequential, IO. The system I spec'd for you is more than 5x superior to
the one above for your workload. As a bonus, 8 drives suck less power
than 20 drives, and it's a 2U instead of 4U system.
Don't be fooled by big sequential numbers. The vast majority of all
workloads are random in nature, not sequential. So build your systems
for fast random IO, especially random writes. Which is exactly what I
gave you. The big sequential system above will be pretty horrible with
a random IO workload such as yours.
--
Stan
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