Xsan Cache Memory limitation

rstasel · Xsan Master Joined: 03 Aug 2007 Posts: 120

All,

I'm curious if anyone else has tried assigning more than 1.5GB of memory to the metadata cache on your MDCs. If you do it in Xsan admin, even with 2.2.1, it does not seem to allow you to enter more than 1536MB. If you do, and hit save, it just goes back to 1536MB.

My MDCs have 8GB of ram each, and it would be nice to assign like, 3-4GB of ram to the metadata cache on the MDCs.

Not sure what would happen if I just edited the volumename.cfgs.

Thanks!

abstractrude · Xsan Master Joined: 13 Mar 2008 Posts: 860

where are you making this change? screenshot? Remember XSAN on leopard in 32 bit.

are you talking about inode cache?

rstasel · Xsan Master Joined: 03 Aug 2007 Posts: 120

"Edit Volume Settings" -> "Cache Settings" -> "Buffer Cache Size".

This is on Snow Leopard, so 64-bit. Shouldn't have any problems, I wouldn't think.

Right now, I've got:

Inode Cache Size at 65536, and Buffer Cache Size at 1536MB.

abstractrude · Xsan Master Joined: 13 Mar 2008 Posts: 860

who told you or where did you read about these recommended settings? are you just putting these numbers in with the hope of increasing performance?

rstasel · Xsan Master Joined: 03 Aug 2007 Posts: 120

Pretty much the latter. Since the more info you can buffer in memory is going to be a hell of a lot faster than reading it off the spindles, I upped it back when I first created the SAN.

Going by: http://wiki.xsanity.com/groups/xsanitywiki/wiki/8bb1a/Anatomy_of_a_.cfg_file.html

It's metadata buffer. So, upping it as much as possible, without hitting the limits of the physical ram, would be a good thing.

hutchenstein · JBOD Joined: 08 May 2012 Posts: 2

Hi Guys,
Did you ever find out the answer to the query?
This thread just goes cold..
Just wondering.
Thanks,