| Modified: Nov 12
2003
|
Using xdisk
Storage
The local utility xdisk (replacing tdisk
and gdisk) is used to administer temporary allocations
of scratch space.
- You are able to extend the storage size and expiration within
limits--a large space can be allocated for only days; a small space
can be allocate months.
- Before your allocation expires, you will be sent several
daily email notices to your email account. (You can
set up a .forward to send the notice to another email
address.)
- Your files are purged once your space allocation expires.
Xdisk areas are backed up but restoring
your files can be tedious.
- The precise space and time matrix will vary as resources
and demand dictate, but this xdisk query
example illustrates the possible combinations.
- The default space and time allocation values
can be changed by Systems, but it is generally for a minimal
space and maximal time.
- Your allocation
- on U-System will be in /xdisk/$USER,
e.g., /xdisk/username
- on Aura (HPC) will be in /scrn/$USER,
e.g., /scr2/username
- on Beowulf will be in /scrn/$USER,
e.g., /scr2/username
Note that Aura's and Beowulf's file
spaces are completely separate systems.
The examples below use these command options.
There is a hostname option (-h) which does
not apply on the U-System or Beowulf.
- Create scratch space
xdisk -c create -m 700 -d 20
Allocation (-m) is in MB. Here is a sample log file
of the create command.
- Get information on your allocation
The response shows your allocation
and the current time/space matrix.
- Extend the life of your allocation
Allocations can be extended for as many days as allowed by the time/space
matrix. (This matrix is displayed with the query option,
#2. The larger the space allocated, the shorter the time allowed;
the smaller the space, the longer its allowable retention.)
This is how the log might appear.
- Modify the size of your allocation
This command will reduce the size of the allocation
from the original 700 MB by 300MB (note the negative 300),
while leaving the expiration of the allocation unchanged
at 40 days (because it had already been extended in #2).
- Delete your allocation
If your allocation is about to expire and you can not extend
its life, then you need to save your files either to another server
or another place within u.arizona.edu. You can use the command
scp to copy a directory, as in this example on U-System (indicated
by the /xdisk):
scp -r /xdisk/username
/scratch/username/save-xdisk
Then you manually delete your xdisk allocation, create a new one
and copy the files back to your new xdisk storage:
scp -r /scratch/username/save-xdisk/*
/xdisk/username
The above command will recursively copy all files and directories back
to your new xdisk allocation. When you have verified that your
files are indeed in your allocation, delete your temporary directory
in /scratch:
rm -r -f /scratch/username/save-xdisk
|
U-System
Information 
UA
Homepage UITS
Homepage