Disk Sizing

[MoobyCow]

I'm more familliar with other database so I've been trying to figure out just how to spec out a new SQL server.

I know I want 4 RAID1 drives

1 - OS
2 - DB
3 - logs
4 - temp DB

I've been unable to find resources that let me know the relative sizes of the drives.

The OS size is obvious, but the ratio of DB size to log size /tmp DB size is not.

Lets say I'm planning on a 100 GB RAID for the DB. What are the sizes I would need for the log and tempdb RAIDS?

 

[JamesLean]

Have a look at this FAQ to start with:

Deciding the best disk configuration for your SQL Server
faq962-5747

--James

 

[mrdenny]

There is no relative size for the logs and temp db compaired to the size of the database.

In order to know the correct size of the log compaired to the database you'll need to know if you are going to be doing more updates and deletes than inserts. When you do an insert data is written to both the database and the log. When you do an insert no new data is written to the database, but new data is written the log. When you do a delete data is removed from the database, but new data is written to the log.

The size of temp db will depened on the kinds of queries that you are doing, and how much data moving you will be doing, as well as the size of the tables, and the size of the indexes.

As for the drive configs see my FAQ that James pointed you to.

Denny
MCSA (2003) / MCDBA (SQL 2000)

--Anything is possible. All it takes is a little research. (Me)

http://www.mrdenny.com

(My very old site)

 

[MoobyCow]

Thank you.

Is there any rule of thumb? We're going to be running several different DBs, not a huge amount of writing to the DB. Most of the work will be in form of queries for reporting purposes.

Do I need a disk the same size as the DB disk or is some fraction of that standard? It's not going to be anything out on the fringes of DB use, I just want a safe starting point to work from.

 

[mrdenny]

If you are going to be mostly running reports than generally you'll want a decent sized log and tempdb space so that you've got enough space to handle loading of data and querying of data.

Denny
MCSA (2003) / MCDBA (SQL 2000)

--Anything is possible. All it takes is a little research. (Me)

http://www.mrdenny.com

(My very old site)