Arenas in full file systems.

[DanKarron at UCBVAX.BERKELEY.EDU]

Here is a problem with Arenas and full file systems:

I am attempting to run my grand opus program on a number of different
sgi systems around here (NYU). All of the public machines have
almost completely full disks. All of the public machines also
have > 32 MB memory which is generally not always in use.

Now I load up my arenas with about 14 MB of pixels to be processed by
my collection of programs. While the memory is available, the disk space is NOT.
So my Arena setup and load program is failing because the Arenas take 
up too much disk space. The system can't run for lack of disk space when
there is lots of memory. I get the pixels from my nfs mounted pixel server
disk, so they (the pixels) don't take up space on the host machine.

This seems odd since the Arena file is only an image of the shared memory
mmap'ed to disk. It should only be flushed to real disk when the Arena is
closed.

Is there any way around this problem ? Consider that most machines run with
full disk file systems. It is harder to ask for 14 MB disk scratch space than
to just keep 14 MB of files just to reserve space for the Arena. 


| karron at nyu.edu (e-mail alias )         Dan Karron, Research Associate      |
| Phone: 212 263 5210 Fax: 212 263 7190  New York University Medical Center  |
| 560 First Avenue                       Digital Pager <1> (212) 397 9330    |
| New York, New York 10016               <2> 10896   <3> <your-number-here>  |