User Scratch Disk Space

SLAC	PEP-II
BABAR
SLAC<->RAL

HEPIC	E,S & H	Databases	PDG	HEP preprints
Organization	Detector	Computing	Physics	Documentation
Personnel	Glossary	Sitemap	Search	Hypernews

User Scratch Disk Space

29 July 1999

Users needing scratch disk space currently have the following options.

Usage:

All scratch disk areas should be used in the same way, i.e. create a directory with YOUR unix userid, then create any temporary files inside that directory.

Scratch disk retention periods (after which your files will be automatically deleted) can be found by looking for a file called "RETENTION" in the top level of the specific scratch directory. This file is really a symbolic link and points to the retention period expressed as a number of days. This retention policy is in effect ONLY for some SCS-managed scratch disk areas. For example:


(Wed 18:07) dragon@phoebe $ cd $BFROOT/work/d
(Wed 18:07) dragon@phoebe $ cd ..
(Wed 18:07) dragon@phoebe $ ls -l RETENTION 
lrwxrwxrwx   1 root     root           1 Jun 29 15:59 RETENTION -> 7

This says that the file retention period for files in $BFROOT/work/d is seven (7) days. A file is a candidate for removal if it has not been modified for at least the retention period.

Space:

Modest amounts of space can be used in the /tmp directory of each Unix machine at SLAC. This space is writable by all users on that machine, thus compete for the space. /tmp is periodically cleaned up by SCS or during system reboots. This space is also used by various compilers, linkers, etc to store temporary files in the process of executing. If the /tmp directory fills up, a machine may crash. Thus, use of this space is recommended ONLY if your demands are very modest (i.e. a very small number of MB).

Other sources of modest amounts of temporary disk space are described in the Local Temporary Storage section of this SCS page.

Larger amounts of disk space may be found in $BFROOT/work where you should use the first letter of your username and cd into that directory. There is currently about 75 GB of space in this area. The RETENTION period is 7 days.

Both shire and percheron, the large Sun application servers, have a large amount of _local_ scratch space in /u1. This space is only visible from shire or percheron, respectively. Shire has about 53 GB of space and percheron has about 60 GB. The retention period is currently infinite (but could change with little or no notice).

A special place for local copies of $BFDIST for doing large builds is available in /u2 on percheron (about 58 GB). Please read the README for usage guidelines.

NOTE: Please see the usage policies for the above types of disk space in this web page.

BABAR maintains a 2 GB disk area in $BFROOT/scratch. Please see the README file for instructions and current usage.

This page maintained by Tom Glanzman