use swap when /tmp its out of space

samuaz · 2012-10-21 08:55:06

hello guys

im new in arch and i love it

i have question its possible use swap partition when the /tmp its full and run out of space, for example a this moment im installing freecad from aur and it need compile opencascade and always the compilation fail because /tmp its out of space, i have 4gb of ram and my /tmp have a size of 1.9gb i like have the /tmp in ram because its more faster than my old hdd. but if possible do that when /tmp its full automatically begins to use swap? at this time to compile OpenCascade I had to make yaourt use another temporary folder to compile as OpenCascade.

when my /tmp its full i check my swap partition and always its never used

other think arch use /tmp in ram as default correct, or am I wrong

thanks to all guys and sorry for my english im speak spanish xD

sakishrist · 2012-10-21 12:31:52

Have you tried remounting /tmp with more GBs?

karol · 2012-10-21 13:05:55

sakishrist wrote:

Have you tried remounting /tmp with more GBs?

+1
You may want to adjust the swappiness https://wiki.archlinux.org/index.php/Ma … Swappiness

Post the output of 'free -m' and 'df -h' from the time you think your /tmp is full.

tomegun · 2012-10-21 14:02:52

If /tmp is a tmpfs, then it will automatically fall back to swap when it runs low on memory. However, it will never exceed the size that you specify. Notice that it should not be a problem to specify a bigger size no memory/swap is actually used unless it is needed (i.e., an empty 10GB /tmp would not consume any ram at all).

samuaz · 2012-10-21 20:55:57

hi and thanks guys

this its my terminal out

[samuel@samuel-laptop ~]$ free -m
total used free shared buffers cached
Mem: 3919 1731 2187 0 54 805
-/+ buffers/cache: 871 3047
Swap: 0 0 0
[samuel@samuel-laptop ~]$ df -h
S.ficheros Tamaño Usados Disp Uso% Montado en
rootfs 228G 68G 149G 32% /
dev 2,0G 0 2,0G 0% /dev
run 2,0G 324K 2,0G 1% /run
/dev/sda2 228G 68G 149G 32% /
tmpfs 2,0G 0 2,0G 0% /dev/shm
tmpfs 2,0G 0 2,0G 0% /sys/fs/cgroup
tmpfs 2,0G 24K 2,0G 1% /tmp
/dev/sda1 92M 30M 58M 34% /boot
[samuel@samuel-laptop ~]$

and this moment i have my /tmp empty because i restart the laptop, but for example if im install a big files from aur like freecad-git its need compile opencascade and its fail because its out of space for continue the compilation and when /tmp its full 1.9/1,9gb its shouldbe start use the swap but its never used when its full the swap always say 0% in the system monitor and other think its when /tmp its full i check my ram avalible in the system monitor and its not full at all its show for example 1.2gb in use of the 4gb, other example its if my /tmp its full i cant load videos in youtube its not load i need clean my /tmp for make space for the videos

so i think my swap partition its not used when the /tmp its full

my fstab its (from the default arch instalation)

#
# /etc/fstab: static file system information
#
# <file system> <dir> <type> <options> <dump> <pass>
tmpfs /tmp tmpfs nodev,nosuid 0 0
# UUID=258158b0-2606-41d4-8e3d-b2b6020cf168
/dev/sda2 / ext4 rw,relatime,data=ordered 0 2

# UUID=bf37f4fb-6112-44e4-bfb4-9b2890bc7133
/dev/sda1 /boot ext2 rw,relatime 0 2

i see i no have a swap partition specified in the fstab but i have a 2GB swap partition created in sda3 but apparently its not active or i miss activate it when install arch i think this its the problem how i can activate it and add to my fstab?

thanks to all guys

Thanoulis · 2012-10-21 23:16:10

In order to mount your swap you can edit /etc/fstab as follows:

/dev/sda3 swap swap defaults 0 0

I will be better/safer tho, to use UUIDS (UUID=uuid_number) instead of /dev/sdx. Have a look at /dev/disk/by-uuid.

falconindy · 2012-10-22 00:15:45

samuaz wrote:

when /tmp its full 1.9/1,9gb its shouldbe start use the swap

No. Your assumption is wrong. You've defined the tmpfs as 2GB. It's never going to occupy more than 2GB. If the tmpfs was 10GB and you ran out of RAM, it would spill over into swap. Keep in mind that by doing this, you leave yourself extremely prone to a kernel panic as memory occupied by files in tmpfs cannot be freed by the kernel in case it needs it.

Last edited by falconindy (2012-10-22 00:16:27)

samuaz · 2012-10-27 05:52:16

hi guys thanks, i activate my swap partition, and no have size defined for the tmpfs i have the default arch configuration, i try compiling a big file for check it, and also if i have problems i try to defined more memory for it

Arch Linux

#1 2012-10-21 08:55:06

use swap when /tmp its out of space

#2 2012-10-21 12:31:52

Re: use swap when /tmp its out of space

#3 2012-10-21 13:05:55

Re: use swap when /tmp its out of space

#4 2012-10-21 14:02:52

Re: use swap when /tmp its out of space

#5 2012-10-21 20:55:57

Re: use swap when /tmp its out of space

#6 2012-10-21 23:16:10

Re: use swap when /tmp its out of space

#7 2012-10-22 00:15:45

Re: use swap when /tmp its out of space

#8 2012-10-27 05:52:16

Re: use swap when /tmp its out of space

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