Re: SSD + RAID

Lists wrote:
> Laszlo Nagy wrote:
>> Hello,
>>
>> I'm about to buy SSD drive(s) for a database. For decision making, I
>> used this tech report:
>>
>> http://techreport.com/articles.x/16255/9
>> http://techreport.com/articles.x/16255/10
>>
>> Here are my concerns:
>>
>>    * I need at least 32GB disk space. So DRAM based SSD is not a real
>>      option. I would have to buy 8x4GB memory, costs a fortune. And
>>      then it would still not have redundancy.
>>    * I could buy two X25-E drives and have 32GB disk space, and some
>>      redundancy. This would cost about $1600, not counting the RAID
>>      controller. It is on the edge.
> This was the solution I went with (4 drives in a raid 10 actually). Not
> a cheap solution, but the performance is amazing.

I've came across this article:

http://www.mysqlperformanceblog.com/2009/03/02/ssd-xfs-lvm-fsync-write-cache-barrier-and-lost-transactions/

It's from a Linux MySQL user so it's a bit confusing but it looks like
he has some reservations about performance vs reliability of the Intel
drives - apparently they have their own write cache and when it's
disabled performance drops sharply.