Recommended amount of swap

[Volodymyr Kostyrko]

05.09.2011 22:48, Dan Nelson написав(ла):
> In the last episode (Sep 05), Sean Hamilton said:
>> What is the state of the art for the recommended amount of swap in
>> FreeBSD? Both "normal" systems with 512 MB - 8 GB of RAM, and large
>> database systems with around 128 - 256 GB.
>
> I suggest 2x RAM for systems less than 4gb or so.  Anything more than 4GB of
> swap is probably never going to be used, and if it is used, you're just
> going to thrash your swap device.  If you have 128GB of RAM and need to swap
> to disk, you desperately need more RAM, not swap :)

My +1 to wishlist, I want OpenOffice to not trash memory when reading 
large xlsx files.

Mem: 1937M Active, 243M Inact, 672M Wired, 98M Cache, 9412K Free
Swap: 36G Total, 21G Used, 15G Free, 59% Inuse, 252K In

    PID USERNAME    THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU
COMMAND
   1912 arcade        5  45    1 23311M  1721M ucond   0  66:07 55.37%
/usr/local/openoffice.org-3.3.0/openoffice.org3/program/so

Different things happens. When I hardly need some swap I think about:

0. More RAM.
1. Spare flash or SSD.
2. Another disk.
3. Touching disk sizes.

Also please note that system that uses at least 1G of swap actively (I 
don't mean tmp/mdfs or long running non active processes) is dripping 
slime and therefor is useless and should be upgraded.

-- 
Sphinx of black quartz judge my vow.