The latest edition to the computers at MCSR is named “redwood”. Redwood is an Altix 3700 supercomputer from SGI running the Linux operating system. Currently redwood operates with 64 processors; more processors may be added later. To obtain an account on redwood users may apply online at https://secure.olemiss.edu/resdb2/.
Users may check their quota by entering “quota”. This command will tell users the amount of disk space that is available to them on both their primary and secondary disk, secondary disk being their “ptmp” (permanent tmp) or “work” disk.
When a user first obtains an account upon entering “quota” the following appears on the user’s screen:
quota
Disk quotas for user ccsam2 (uid 872):
Filesystem blocks quota limit grace files quota limit grace
/dev/xscsi/pci02.02.1/target7/lun0/part2
56 39000 42000 16 0 0
The above indicates that user ccsam2 has 16 files, most of which are created by the system and not by user ccsam2. ccsam2 is allowed “39000K” of disk quota and is allowed to go over another “3000K” or about %10. Once a user goes over “42000”, then the user can’t copy files or use “vi” to create new files. At this time user should delete some of the un-needed and old files.
Below is an example of a disk which is full and user tries to create a file using vi.
"junk1" Permission denied
User is not permitted to close the above file called “junk1” created using “vi”. In essence the system is telling the user that “you haven’t got room to store your data”.
The following message appears on user’s screen when a user disk is full and the command “quota” is issued.
Over disk quota on /users2, remove 3468K within 1.2 days
Here is another example of “quota” where user has created many files and is nearing his quota.
quota
Disk quotas for user ccsam (uid 515):
Filesystem
blocks quota limit
grace files quota
limit grace
/dev/xscsi/pci02.02.1/target7/lun0/part2
37744 39000
42000 139 0
0
/dev/xscsi/pci02.02.1/target5/lun0/part1
25908 20000000 21000000 357 0 0
In the above example user has on his primary disk “37744K”, and on his secondary disk “25908”. His limit on his temp disk is “20000000K” which is about 512 times the quota that he has on his primary disk: “39000K”. This user is permitted to go over his quota on his temp disk by “1000000K”, about %5. Users are encouraged to use their secondary (ptmp) disk, which is why they are given so much more disk quota on their ptmp disk. This user has 139 files on his primary disk and 357 on his secondary (ptmp) disk.
If the user “ccsam2” enters: “ls -lt test1.f”
To look at one of his files, a file named “test1.f”, in this case a very small Fortran file which contains only 6 lines, the following will appear on the user’s screen.
-rw-r--r-- 1
ccsam2 mcsr 188 Sep 24
Above tells the date that the file was created and “188” is slightly more than the size of the file, e.g. the number of characters that the file contains.
When a user first obtains an account, there are several system files that are created by the system. One of these files is called “.viminfo”. This file is created by a program called “Vim”, Vim is a text editor that is upward compatible to vi. Most users are familiar with vi, which is a text editor. When a user accesses vi through redwood, he is actually is accessing Vim.
Suppose that a user executes a C or a Fortran program whose output is very large, e.g. more than 42000K (more than the quota that he is allowed). Once the output exceeds 42000K the following happens. First the program sits there and will not run (remains idle); that is the program tries to run but can’t run because it can’t output its results. At this time if the user tries to create a new file using “vi” after the file is created the “vi” will not allow the user to close the file and the following message is issued by “vi or viminfo”:
E138: Can't write viminfo file /users/ums/ccsam2/.viminfo!
Hit ENTER or type command to continue
The above message appears even if the user tries to create a file on his secondary (ptmp) directory even though there may be plenty space left under his /ptmp quota. This is a warning given by “viminfo” that the user’s Home directory disk quota is full and therefore he is not permitted to create a file even on his /ptmp.
