Solved

Dell 6800 PERC4 adapter: read/write cache

Posted on 2007-04-06
6
591 Views
Last Modified: 2008-09-13
I have Dell 6800 server with PERC4 Ultra320 SCSI RAID controller with 256 MB cache.

I did some tests and I have found, that this cache is probably divided to cca 240 MB read cache and only 7 MB write cache. I have used xdd test tool to bypass filesystem cache and I was able to read 240 MB files with very high transfer rate while with 245 MB files transfer rate dropped to about 30%. Write test showed this transfer rate drop when file size changed from 7 MB to 8 MB.

I'd like to increase write portion of the cache. I'm using command line utility named megarc to set controller parameters and I can't see any parameter, that could affect cache division.

Does anybody know, whether it is possible to change the size of write cache on PERC4 controller ?
0
Comment
Question by:Jan_Franek
  • 2
  • 2
6 Comments
 
LVL 4

Expert Comment

by:BPiotrowski
ID: 18908490
Have you tried to set this in the Perc controller BIOS ? There should be a way to set the controller for how you want the cache to be divided - default I believe is 50/50.

-Bart
0
 
LVL 14

Author Comment

by:Jan_Franek
ID: 18916298
Hi Bart,
do you know, where in controller BIOS can be this setting ? I haven't found it yet.
Jan
0
 
LVL 4

Expert Comment

by:BPiotrowski
ID: 18917394
Are you able to get into the BIOS controller ? once you are in - on the virutal disk setting - there should be an allocation of cache - read/write percentage. Hmmm.. it may also be only if you create a new virtual disk....which is not going to help you. - Do you have the newest firmware for the raid controller ?
0
 
LVL 14

Author Comment

by:Jan_Franek
ID: 21247907
Sorry, I have forgotten, that this is still open.

I have upgraded firmware and BIOS too, but there's no way to change cache allocation. So probably the answer to my question is: No, it can't be done.
0
 
LVL 1

Accepted Solution

by:
Computer101 earned 0 total points
ID: 22469008
PAQed with points refunded (500)

Computer101
EE Admin
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Patch Management is administrated by page 129 of  the following document:     http://support.dell.com/support/edocs/software/smdmc/11/en/ug/ug.pdf However, there are issues with Patch Management with FTP (for instance, a slow Internet connectio…
Learn about cloud computing and its benefits for small business owners.
Email security requires an ever evolving service that stays up to date with counter-evolving threats. The Email Laundry perform Research and Development to ensure their email security service evolves faster than cyber criminals. We apply our Threat…
The Email Laundry PDF encryption service allows companies to send confidential encrypted  emails to anybody. The PDF document can also contain attachments that are embedded in the encrypted PDF. The password is randomly generated by The Email Laundr…

828 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question