There are tons of articles out there recommending RAID/ LUN/ drive configurations for SQL Servers, but most leave me still questioning as they usually state "it depends" and for this reason I'd like to provide some specifics and get some more direct recommendations:
I have a client who already installed SQL Server on a Cybernetics SAN and here are the specifics:
• SQL Server 2008 R2 installed on a virtual server
o Cybernetics miSAN-D8/T16 SAN iSCSI storage appliance o 4+1 GbE ports o 8 GB SAN controller cache o USB and eSATA ports o Two miniSAS device o 8 drive bays all filled with 600 GB SATA-II 7.2K drives (5.4 TB total) o All 8 drives set up in RAID 6 o Three logical drives: 1. C (156 GB) – for system and apps (IIS, web app, SQL, SSIS, CA ArcServe backup app, VIPRE antivirus) 2. E (1.64 TB) – for data, logs and tempdb 3. F (1.80 TB) – for backups
The SQL Server is more read intensive, with data bulk loaded nightly like a data warehouse and the web app used for looking up and reporting on the data.
Periodically the client experiences sluggishness, sometimes severely, for short periods with the web application. I’ve also noticed Brent Ozar’s Blitz script reveals slow writes to the E drive at times.
I am wanting to suggest the client reconfigure their SAN as follows:
- C ( 156 GB, raid 1) – for system and app files.
- D ( 1200 GB, raid 10/5) – for sql data files.
- L ( 444 GB, raid 1) – for log files.
- T ( 1200 GB, raid 5) – for tempdb data files.
- Backup to a different san or network location and archive to tape.
But at the very least I believe the client should do the following:
- Move backups to a different SAN or network location, in order to free up the F drive for SQL use as well as for better DR.
- Move log files and tempdb data files to the F drive.