Re: SSD Drives

On 04/02/2014 02:55 PM, Bret Stern wrote:
> Care to share the SSD hardware you're using?
>
> I've used none to date, and have some critical data I would like
> to put on a development server to test with.
>
> Regards,
>
> Bret Stern

SSDs are ridiculously cheap when you consider the performance
difference. We saw at *least* a 10x improvement in performance going
with SATA SSDs vs. 10k SAS drives in a messy, read/write environment.
(most of our tests were 20x or more) It's a no-brainer for us.

It might be tempting to use a consumer-grade SSD due to the significant
cost savings, but the money saved is vapor. They may be OK for a dev
environment, but you *will* pay in downtime in a production environment.
Unlike regular hard drives where the difference between consumer and
enterprise drives is performance and a few features, SSDs are different
animals.

SSDs wear something like a salt-shaker. There's a fairly definite number
of writes that they are good for, and when they are gone, the drive will
fail. Like a salt shaker, when the salt is gone, you won't get salt any
more no matter how you shake it.

So, spend the money and get the enterprise class SSDs. They have come
down considerably in price over the last year or so. Although on paper
the Intel Enterprise SSDs tend to trail the performance numbers of the
leading consumer drives, they have wear characteristics that mean you
can trust them as much as you can any other drive for years, and they
still leave spinning rust far, far behind.

Our production servers are 4x 1U rackmounts with 32 cores, 128 GB of ECC
RAM, and SW RAID1 400 GB SSDs in each. We back up all our databases
hourly, with peak volume around 200-300 QPS/server with a write ratio of
perhaps 40%, and a iostat disk utilization at about 10-20% in 5 second
intervals.

-Ben