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Deduplications Storage Folder - RAID 5 vs RAID 10

Created: 28 Feb 2012 • Updated: 30 Sep 2013 | 5 comments
This issue has been solved. See solution.

After the first full backup run to a dedup store, is read speed then more important than write speed for deduplication?
In that case, would RAID 5 perform better than RAID 10 since it provides better read speeds?

My storage is Dell MD1000 DAS with 10x SATA 2TB 7.2K connected via SAS-cable to a PERC6/E in a Dell R710.

Also, does anyone have recommendations on whate Stripe Element Size to set? 64k stripe and 64k NTFS cluster?

Comments 5 CommentsJump to latest comment

pkh's picture

Quoting from the Best Practices

http://www.symantec.com/docs/HOWTO21767

Disable RAID caching on the disk where the deduplication storage folder is located.

SOLUTION
ikmit's picture

I now have the following set (PERC6/E defaults):
Read Policy: No Read Ahead
Write Polciy: Write Back
Disk Cache Policy: Enabled

Should I change this to:
Read Policy: No Read Ahead
Write Polciy: Write Through
Disk Cache Policy: Disabled
?

Is this to better the performance or for stability reasons?

CraigV's picture

...enabling Write Through means you're hitting disk, and not going through cache. It might be a bit faster, but you would lose the ability to retain data in cache should you have power loss for example.

Alternative ways to access Backup Exec Technical Support:

https://www-secure.symantec.com/connect/blogs/alte...

SOLUTION
ikmit's picture

OK, but if I set Disk Cache Policy to disabled, recommended best practise, does it then matter if Write Through or Write Back is configured?

Disabling Disk Cache would force Write Through?

CraigV's picture

...that's something you will have to check, and come to a compromise between best practice and performance, and data protection in the event of a power failure etc.

Alternative ways to access Backup Exec Technical Support:

https://www-secure.symantec.com/connect/blogs/alte...