add vm.memory.size[pfree]

[SharkCZ]

I have created support for vm.memory.size[pfree] in the linux agent. It is modeled after "pfree" function for swap.

[Alexei]

Thank you. The patch will be reviewed and integrated into 1.4.3.

[Sasha]

Thank you!
The patch is integrated for Linux. FreeBSD and Windows are also supported.

[lamont]

free memory is a fairly useless statistic under modern unix OSen since it just trends to nearly zero as the buffer cache uses it up. i'd really like to see a free + buffers + cached statistic like the one that /usr/bin/free (on redhat) returns on the second line. and ideally a used statistic that was total memory - free - buffers - cached.

[lamont]

okay, that's just creepy that vm.memory.size[available] just got released in 1.4.3 ... talk about psychic developers...

still, it'd be nice to be able to do more advanced math on items. i'd like to be able to make a stacked graph of:

1. total memory - vm.memory.size[available] (ie. used memory)
2. vm.memory.size[buffers] + vm.memory.size[cached] (ie. total disk cache)
3. vm.memory.size[free]

which should always add up to total memory and should give nice colors for program memory, disk cache and free list.

[lamont]

here's a patch to add pavailable to 1.4.3, like pfree.

rationale is to set a percentage level like 90% above which the box has insufficient buffer cache and is likely swapping or simply making inefficient use of the buffer cache.

[snailgame]

1.4.5 memory pfree

way zabbix 1.4.5 do not support memory pfree mode?

[antani]

way zabbix 1.4.5 do not support memory pfree mode?

Nope.

I workarounded monitoring free percentage in trigger:
{host:vm.memory.size[free].last(0)}<{host:vm.memory.size[total].last(0)}*20/100