heavier memory use on 11.23 rp4440 vs 11.0 v2500

[Steve Post]

The new box uses more memory than the old one.
Anybody know of new, unneeded processes in 11.23 that I can turn off?

system memory on v2500: 380 megs.
system memory on rp4440: 2.6 GIGS

There is a vxsvc job that's using 46meg. I'm not using VXVM but maybe that's what this is?

I'm guessing here, but the disks and filesystems are a lot larger on the new box (72gig disk vs 8gig disk). The extent size is 16megs vs 4megs. Perhaps there is a document that shows how kernel parameters and the layout of volume groups affects kernel memory?

[James R. Ferguson]

Hi Steve:

As far as kernel memory and LVM goes, the immediate parameter that comes to my mind is that about 4-8KB of kernel memory is used for every increment in 'maxvgs'.

Regards!

...JRF...

[Steve Post]

Well v2500 has maxvgs=20, the rp4440 has maxvgs=10. So that's not it. But I am hoping I have a parameter off enough to at least explain the difference. I know there's some document in the itrc that shows how the kernel parameters for volume groups use up memory. But I can't find it.

Anyway this idea about volume groups is just a guess. Perhaps it's just that the newer boxes use this much because it's a "more modern"?

I attached the kernel parameters into one text file.

[Steve Lewis]

Well if the new box has more base RAM installed, then dbc_max_pct 20% will allocate 20% of a bigger memory, giving a bigger system total.

What I have found is that there are more unnecessary processes started by default e.g.
samba/cifs, httpd.
Plus others which have been re-engineered, like the scrdaemon.
Then you need to be aware of Java...

[Steve Post]

It took a lot of digging through...GOOGLE. But I found something.

Kernel variable vx_ninode was set to a default of 0. This needed to change. I changed it to 12000 because 11 was the smallest allowed.

Supposedly "sar -v" shows that vx_inode should be above the number of open vx inodes. It looks like it's 900.
And the adb command showed vx_inode was was set to somewhere over 300,000.

300,000 is a lot bigger than 900.

After I changed vx_inode (to 12,000), I got over a GIG of memory back.

[Steven E. Protter · Accepted solution]

Shalom,

That parameter you found pretty much lets the system change it whenever it feels it needs to. This is also a problem with 11 vi btw and its very expenseive in terms of CPU and memory to change it.

Best to set it to a number your system can live with. Its all part of the tuning process.

The OS does more than 11.00 and its reasonable to expect it to use and need a little more memory.

SEP