I hate to say it depends.... but....

Are you sharing dasd between linux servers?  If yes, you
probably want to share caching using MDC. Or do you want each linux
server to cache it's own data?

Then the issue is do you want to use track cache or
block cache.  block cache is more efficient, blocking
data based on 4k blocks.  track cache is most inefficient,
as it focuses on tracks. Linux uses blocks, using block
cache is a more efficient use of memory.

To use track cache, the disk has to be formatted correctly
AND you have to use the diagnose driver. This is not-trivial.

If you want to run lots of linux guests, you need to make
them efficient, this means they share resources. and should
use block cache MDC. If you run few linux servers, it most
likely does not matter much.

And, you WILL want to measure the results. by user, by disk,
and by system, so should look for tools that can help you
understand the impacts of your options....


>I am wondering if I am getting to the list as I did not get a single
>response to my mdcache question.  A very unusual occurrence.
>
>>What is the recommendation for the mdcache settings for Linux guest
>>minidisks?  Should it be used or not?
>
>
>
>Mark D Pace
>Senior Systems Engineer
>Mainline Information Systems
>1700 Summit Lake Drive
>Tallahassee, FL. 32311
>[EMAIL PROTECTED]
>Phone: 850-219-5184
>Fax: 850-219-5050
>http://www.mainline.com







"If you can't measure it, I'm Just NOT interested!"(tm)

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