AIX PS/2 1.3 tar file size error if using console

UNIX AIX
1

Hi, I'm a hobbyist and have been having some fun with AIX PS/2 1.3 (circa 1992!) on a PS/2 Model 95. I have it running perfectly! I like vintage unix workstations (1980's and early 90's) and once I get an old OS configured nicely I like to back it up the various ways possible available to that platform, usually tar to NFS, and dd. I'm seeing a strange behavior regarding tar. If I'm sitting at the console, either a shell in text console, or a shell within X-Windows/Motif, and run my tar command, then when the tar archive file reaches EXACTLY 4MB on the NFS drive it stops with the error "tar: write error: File too large". However, if I telnet into this AIX machine and run the exact same tar command to the exact same NFS directory it succeeds (total tar file size is about 110MB when it completes). I use this NFS drive for all my backups from all my Unix machines so I know it can handle 4MB files, and again, if I run the tar command from a telnet session it works fine.

Here's my tar command: tar -cvf /nfs/backups/scotty/data /bin /etc /generic /lib /local /qmsg /shlib /supplies /u /unix /usg /usr /usg /scotty 1> /nfs/backups/scotty/output 2> /nfs/backups/scotty/errors

Any ideas as to why tar thinks it has a 4MB limit when using the console, but not when using a telnet session?

Thank you!

2

...and one more data point. If the tar command runs via a cron job then it completes properly as well.

3

Hmmm........a bit of a mystery.....

I see you are using the tar -v (verbose) switch, so when it stops with the error, does it always stop on the same file? If so, what file is it? Is that file associated with the (console) terminal, e.g. /dev/tty??. If you exclude that file does it stop on the next file, or does it then complete?

Another thought is, have you compared the local environment variables set when you login on the console to those set when you telnet in? Is there any difference?

What you describe certainly seems to indicate a problem specifically using the console.

4

Another thought..... If you issue a command from the console to simply copy a file greater than 4MB to the NFS volume will it let you do it?

5

Hi @bminear

From both situations, before you run your tar command, check this:

ulimit -a

Let's us know what you discover!

6

@Neo for the win!

ulimit file size limit when I'm in root console shell is 8192 blocks (4MB)...doh!
ulimit file size limit when using root in telnet is 524280 blocks (256MB)

I used ulimit to increase the file size limit and my tar command worked perfectly from console.

Thank you!