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I'm on Ubuntu 9.04 and I've got the following problem:

The folder /tmp normally has a tmpfs mounted in it. On one machine, this isn't the case anymore. I don't know what happened to have it that way.

mount doesn't tell anything about this directory and it isn't a symlink neither.

Well I simply could remount some new ramdisk, sure. But I don't know the size etc.

Even on a fresh system, mount doesn't tell anything about /tmp

some friend told me to look at /etc/init.d/mountoverflowtmp, but when i try to launch this command with a "start" appended to it, I'll receive

test: 53: Illegal number: Verfügbar

(Verfügbar = Available)

EDIT: /etc/fstab on the "broken" machine doesn't contain anything about /tmp. Neither does it on a freshly installed system

Any idea is appreciated, regards

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can you edit your question to show (at least) the fstab line that mounts tmp? – DaveParillo Sep 29 '09 at 20:16
I don't see the point in sacrificing ram over hard disk space, but if I had to guess you just need to re add it to you fstab – monkey_p Sep 29 '09 at 20:24
also mount will only tell you what's in your fstab or current mount info – monkey_p Sep 29 '09 at 20:27
@DaveParillo: done. neither a working nor the "broken" system tells anything about fstab – Atmocreations Sep 30 '09 at 18:38
So, you don't know how your ramdisk was getting mounted in the past, and now it's not working and you're trying to ... what? Do you need help making a ramdisk? Typically ramdisks are not configured by default, so someone would had to have set that up somewhere. – DaveParillo Oct 1 '09 at 0:22
up vote 1 down vote accepted

You don't need a "ramdisk". And in my opinion, Linux's ramdisk support sucks... needing to set up kernel parameters, etc.. to get a proper large size. The only advantage to a "ramdisk" is you can partition it, refer to it like a hard disk device (eg. in an fdisk command, a dd command, etc.). You want tmpfs, which is a file system running on RAM (or swap) without all the disk device stuff in between. Just simply add what you expected to find in your /etc/fstab, then mount it.

choose whichever editor you like, one of the following for example:
sudo pico -w /etc/fstab
sudo vim /etc/fstab

    # device mountpoint type  options  dump pass
    # ------------------------------------------
    none     /tmp       tmpfs defaults    0    0

sudo mount -a

And personally, I don't really like tmpfs on my /tmp... it runs out of space too fast. And with the built in automatic file caching on ext, you don't really need tmpfs anyway (except for writing large things, but then you fill up the disk... so what is the point?).

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