[Novalug] /var log and other partitions

[Jeff Stoner]

On Mon, 17 Dec 2007, maxpublic08 at maxwellspangler.com wrote:

>> Assuming that /var resides in its own partition, what happens if it fills
>> up? What are the consequences to the system, will it still be online but 
>> the
>> daemons/services would crash?
>
> My guess is that most programs would continue to operate.  They should be 
> setup to attempt to write to log files but failure to write to a log file is 
> not critical for most programs and they should simply move on to their real 
> work.

That's a pretty big assumption to make. Try it and see.  :-)
Don't feel like filling up /var/log, then use chattr and make a log file 
immutable and see what happens.

Of course, standard disclaimer applies. Do it on a test server, not a 
production server. If your kid/cat/dog grows a third eye, not my fault.

> For a desktop system, I don't bother with a seperate /var these days.. For a 
> server, it'd be a good consideration in some cases.

Some cases? I argue all cases. The /var file system gets used for a lot of 
things. Redhat's build of PostgreSQL and MySQL both have their data 
directories in /var, mail queues and mail spools are in there. Pid files 
and lock files. Redhat's up2date cache. Oodles of things keep goop in /var 
so it's a very good idea to know what you use and partition appropriately.

Oh, and make sure your disk space checking script/program doesn't write a 
temporary file. What would happen if that partition were to fill up? Would 
your check detect that and report it appropriately or does it fail 
miserably? I remember a time (years ago) when Big Brother gave some weird 
message that didn't convey the fact that the partition  where the disk 
check wrote its temp file filled up.

--Jeff

"I am not available for comment"