On Wed, Jan 27, 2010 at 9:23 PM, bofh <goodb...@gmail.com> wrote:
>> The idea is to limit memory such that running out of RAM+swap is not
>> possible, or unlikely. You can set the limit on the allowed number of
>> processes as well.
>
>
> $ ulimit -m
> 971876
> $ dmesg | grep real\ mem
> real mem = 1039691776 (991MB)
>
> So... this box should run only one process?
>
> $ ps -auxww|wc
> 54 713 4936
>
> If I were to use the max memory usage of each process, I would need a
> 53Gig ram machine?
Hmm seems like someone is playing dumb or trolling... Have you read
the man pages? Read setrlimit(2), read your shell's man page. Read the
login.conf man page.
$ man ksh:
[snip]
-d n Impose a size limit of n kilobytes on the size of the data
area.
-f n Impose a size limit of n blocks on files written by the
shell and its child processes (files of any size may be
read).
-H Set the hard limit only (the default is to set both hard
and soft limits).
-l n Impose a limit of n kilobytes on the amount of locked
(wired) physical memory.
-m n Impose a limit of n kilobytes on the amount of physical
memory used.
-n n Impose a limit of n file descriptors that can be open at
once.
-p n Impose a limit of n processes that can be run by the user
at any one time.
-S Set the soft limit only (the default is to set both hard
and soft limits).
-s n Impose a size limit of n kilobytes on the size of the
stack area.
-t n Impose a time limit of n CPU seconds spent in user mode
to
be used by each process.
[/snip]
I use 'chpst' from the runit package in my run scripts though.
$ man chpst
[snip]
-m bytes
limit memory. Limit the data segment, stack seg-
ment, locked physical pages, and total of all seg-
ment per process to bytes bytes each.
-d bytes
limit data segment. Limit the data segment per
process to bytes bytes.
-o n limit open files. Limit the number of open file
descriptors per process to n.
-p n limit processes. Limit the number of processes per
uid to n.
-f bytes
limit output size. Limit the output file size to
bytes bytes.
-c bytes
limit core size. Limit the core file size to bytes
bytes.
[/snip]
I just use '-m' with it.
An additional layer of protection from setrlimit() is great to have
even if your daemon limits itself. If there's a bug and a process
starts eating away at memory, it will be killed.
Services as run by 'runit' are supervised by 'runsv' so if a daemon
dies (for any reason, just think of some reasons) it will get
restarted in a second. With runit you can configure some services not
to get restarted, run a script when a service exits, etc, etc. More
features than 'daemontools', but daemontools-compatible.
smarden.org/runit
