tmpfs Initial Size

Megatog615 · 02-12-2007, 01:06 AM

I have a tmpfs set up for /tmp, and it works. However, it initially has a 96MB maximum capacity, causing swap usage from applications. My laptop only has 192MB of ram, so this is bad. I'd like it to initially use less ram(like around 16MB) instead of 96MB.
There doesn't seem to be an option for this. Is this possible through kernel recompiling?

unSpawn · 02-12-2007, 05:30 AM

No, it means that if you set the size flag to 96MB it can allocate max that.
If there's nothing in your tmpfs it won't take up resources.

syg00 · 02-12-2007, 06:09 AM

Or to state that another way - with 192 Meg of RAM you probably should *not* be using tmpfs for /tmp
tmpfs by design will use page cache and hence be subject to swapping. You can limit the (maximum) size of it, but that is rarely likely to be a good idea.

Megatog615 · 02-12-2007, 10:20 AM

Well I set it up to create less hard drive usage, but it seems it's just making the swap get used more often(thereby defeating the purpose) so I guess I'll just remove it.

syg00 · 02-12-2007, 03:35 PM

If you are concerned about disk occupancy, simply clear /tmp on shutdown.
If you are concerned about disk I/O, not much you can do, although I wouldn't normally expect /tmp to contribute much.

nx5000 · 02-13-2007, 04:39 AM

The size of /tmp is kept in variable TMPFS_SIZE in /etc/default/tmpfs
TMPFS_SIZE = 16

If you want to clean /tmp at startup, you should create this link:
/etc/rcS.d/S36mountall-bootclean.sh pointing to ../init.d/mountall-bootclean.sh