View Full Version : [ubuntu] /tmp and Virtual Memory Question

August 29th, 2012, 05:17 PM
I am a little confused about Virtual Memory, Swap, and the /tmp folder. I did a stock install of Ubuntu server on a system that only has about 1GB. I installed Webmin and needed to do an update. It failed because it said my /tmp dir was too full. I check and it appeared that /tmp was using RAM/Swap Disk and was limited to only 1024 Kb. I searched and found some docs and used Webmin to up the amount to 100Mb, but it couldn't mount it because it was in use. So I was able to save it and rebooted.

Now I appear to have a /tmp that is 100Mb in size, but it appears that my Virtual Memory is gone. My home screen shows this:

Real memory 938.01 MB total, 121.94 MB used
Virtual memory 1.42 GB total, 0 bytes used
Local disk space 1.60 TB total, 205.66 GB used

And my Disk and Network Filesystems tab looks like this:

Mounted as Type
In use?
Saved? /proc Kernel Filesystem (proc) proc
Yes (https://norad-server:10000/mount/unmount.cgi?index=1) Yes / (Root filesystem) (https://norad-server:10000/mount/edit_mount.cgi?index=1) New Linux Native Filesystem (ext4) LVM VG mapper, LV NORAD--SERVER-root 15% Yes (https://norad-server:10000/mount/unmount.cgi?index=0) Yes /boot (https://norad-server:10000/mount/edit_mount.cgi?index=2) Old Linux Native Filesystem (ext2) Partition with ID afd04771-882d-48a6-9ac3-10507241686a 87% Yes (https://norad-server:10000/mount/unmount.cgi?index=11) Yes Virtual Memory (https://norad-server:10000/mount/edit_mount.cgi?index=3) Virtual Memory (swap) LVM VG mapper, LV NORAD--SERVER-swap_1
No (https://norad-server:10000/mount/mount.cgi?index=3) Yes /media/floppy0 Unknown Type Floppy disk 0
No (https://norad-server:10000/mount/mount.cgi?index=4) Yes /mnt/ide_drive1 (https://norad-server:10000/mount/edit_mount.cgi?index=5) Linux Native Filesystem (ext3) SATA device A partition 1 33% Yes (https://norad-server:10000/mount/unmount.cgi?index=12) Yes /tmp (https://norad-server:10000/mount/edit_mount.cgi?index=6) RAM/Swap Disk (tmpfs) tmpfs 0% Yes (https://norad-server:10000/mount/unmount.cgi?index=14) Yes /sys Kernel Filesystem (sysfs) sysfs
Yes (https://norad-server:10000/mount/unmount.cgi?index=2) No ... /fs/fuse/connections FUSECTL none
Yes (https://norad-server:10000/mount/unmount.cgi?index=3) No /sys/kernel/debug DEBUGFS none
Yes (https://norad-server:10000/mount/unmount.cgi?index=4) No /sys/kernel/security SECURITYFS none
Yes (https://norad-server:10000/mount/unmount.cgi?index=5) No /dev RAM/Swap Disk (devtmpfs) udev 0% Yes (https://norad-server:10000/mount/unmount.cgi?index=6) No /dev/pts Pseudoterminal Device Filesystem (devpts) devpts
Yes (https://norad-server:10000/mount/unmount.cgi?index=7) No /run (https://norad-server:10000/mount/edit_mount.cgi?temp=1&index=8) RAM/Swap Disk (tmpfs) tmpfs 0% Yes (https://norad-server:10000/mount/unmount.cgi?index=8) No /run/lock (https://norad-server:10000/mount/edit_mount.cgi?temp=1&index=9) RAM/Swap Disk (tmpfs) none 0% Yes (https://norad-server:10000/mount/unmount.cgi?index=9) No /run/shm (https://norad-server:10000/mount/edit_mount.cgi?temp=1&index=10) RAM/Swap Disk (tmpfs) none 0% Yes (https://norad-server:10000/mount/unmount.cgi?index=10) No /media/usb0 (https://norad-server:10000/mount/edit_mount.cgi?temp=1&index=13) New Linux Native Filesystem (ext4) SCSI device C partition 1 9% Yes (https://norad-server:10000/mount/unmount.cgi?index=13) No Virtual Memory (https://norad-server:10000/mount/edit_mount.cgi?temp=1&index=15) Virtual Memory (swap) /dev/dm-1
Yes (https://norad-server:10000/mount/unmount.cgi?index=15) No
I think that last Virtual Memory entry was put in because I tried to turn the first Virtual Memory entry on.

I just want to make sure that Apache and MySQL will run as fast as they can and that I don't crash the server by running out of memory. The server is just being used a home server so I can learn this stuff. How do I make sure that Vitual Memory is setup correctly along with Swap and /tmp?

August 29th, 2012, 09:27 PM
Post the output of mount.

October 24th, 2012, 05:39 PM
/dev/mapper/XXXXX--SERVER-root on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /tmp type tmpfs (rw,mode=1777,size=104857600)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/sdc1 on /media/usb0 type ext4 (rw,noexec,nodev,sync,noatime,nodiratime,user_xatt r,barrier=1,data=ordered)
/dev/sdb1 on /boot type ext2 (rw)
/dev/sda1 on /mnt/ide_drive1 type ext3 (rw)
/dev/sdc1 on /var/lib/backuppc type ext4 (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)