Using /tmp and /var/tmp for temporary storage

If you need to store large files on a temporary basis and don't have enough room in your quota for them, you might consider using /var/tmp and /tmp on the shell hosts. These directories are available to you and the data stored there does not count against your quota.

Here's what you need to know about /var/tmp and /tmp:

• /var/tmp and /tmp are shared space, and are used by numerous commands as a matter of course. It is your responsibility to make sure that your use of the space does not interfere with others' responsible use of the system.
• Unlike unlike your home and web directories, /tmp and /var/tmp are separate and discrete across the Panix userhosts. So, if you put a file into /tmp on panix1, it will not be accessible on panix2, panix3, or panix5.
• Files in /tmp and /var/tmp are removed after 30 days, regardless. If you need to keep a large file for longer than that, you should make arrangements to purchase more disk space.
• There are differences between /var/tmp and /tmp:

  The basic difference is that anything in /tmp is deleted when the machine reboots. (This is rare, but both scheduled and unscheduled reboots happen, so if you need short-term survival of a file, put it in /var/tmp.

  Notwithstanding, files in /var/tmp on a particular machine might be destroyed if there is a hardware failure, system upgrade, observation by staff that we're low in space in /var/tmp on a particular box, or any other maintenance. (Again, this is rare, but it means that you cannot count on files stored in /var/tmp either.

• /var/tmp and /tmp are not necessarily the same size on the different machines, and are likely to have different amounts of space available (depending on what other users have stored there). Please check (use df) before using space there.

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  © Copyright 2007 Public Access Networks Corporation
  

  Last modified: February 14, 2007
  Send suggestions and bug reports to helpmaster@panix.com

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