Hi sysadmins!
I'm making a detailed report of memory use on my installation and I've seen
extrange UBC's behaviour, I mean, memory use is mainly by the UBC. For
example, on a AS8400 4 GB memory, I've follow data for a 1-month period
(Megabytes):
wired: 246,81
Active: 2966,9
UBC: 2666,8 ( 2,6 GB for I/O caching !!!)
Inactive: 437,1
Free: 361,27
That is, most of the active memory is used by UBC, and the rest, for
processes
This information is taken from the collect utility.
It's true that I've high UBC max percent value (100% in some cases), but I
understand this should be dinamically, if I've high I/O load, memory used
by caching I/O data should be high, but I've observed that inmediatly to
boot the machine, operating system assigns a high amount of memory to the
UBC, and when there's memory demmand, both active & UBC increases
simultaneously when -theorically- if the free pages list goes under
vm_page_free_target, the pages assigned to UBC over ubc_borrow_percent
should be reclaimed.
I've read about this on System Configuration & Tunning guide, but I think
it isn't very very well explained, so I should be graceful if any of you
should say me links, documents or any references that explained this theme
better.
Please, respond to romero_a5_at_tsm.es
Thanks in advance.
Received on Fri Mar 16 2001 - 10:18:18 NZDT