We have an application which runs already with its database on server. Because of the large amount of I/O (read and write) from this applications database we have very slow responses to our queries. So, we've decided to build a new server machine to install there that application with its database. The database size is 15Gb with 10-100 transactions/sec ,there are at least 5 physical users and 10-20 other from other applications which connects to this database and the average IOPS is 150 to 200.
The machine we're thinking to buy is detailed below. Interesting points:
- Two raid 1 arrays. one for the database and another one for the system.
Machine Specs:
- Xeon 2.4Ghz
- 12GB RAM
- Two raid 1 arrays. 4 146GB 15K disks
- Windows server 2008 R2
- Microsoft SQL Server 2008 standard.
What do you think about it??
You don't mention which specific Xeon it is - there is huge variety in performance based on the model, it would be good to know.
You could consider increasing the memory in an effort to hold all data in memory all the time - see if you can go up to 16-24GB.
Do you know the overall profile of the database? is it reading most of the time with few writes, or is it writing all the time? how many disk slots have you available and of what type/size/speed/physical-size?
Something is wrong here. If you get ONE Velociraptor with 10.000 RPM you have a higher IO budget than 150 to 200 OPS.
150 to 200 IOPS are not that much.
Get a low cost SSD (32, 64GB) and use that. A LOT more IO than the 15k discs, and those can be gotten cheaper, too.
Difficult to say if the spec you suggest will be adequate without knowing a lot more about what the DBMS is actually doing.
One thing which stands out is that the 'system' mirror is going to be relatively inactive - I'd recommend a single volume of raid 0+1 (mirror a stripe set on disks 1 and 3 on disks 2 and 4). Although since the memory you're proposing is nearly the same size as the DB itself, you may get more benefit from spending the money on just 2 disks and adding more cpu cores.
C.