AIX problems

[elee4fg at jetson.uh.edu]

From: seng Gan
Star Enterprise

Here are the problems that I known about:
I have AIX 3.1 running on 540 and 530.
540 and 530 each has 3 IBM 857MB internal harddisk and 2 external 1 GB
harddisk.
1) csh does not support suid. If your csh suid scripts file has this
  #!/bin/csh
   It won't work.
  Your need to do this in ksh
  /bin/csh <your suid script file> ( without #!/bin/csh )
2) tar to 2.3 GB 8mm drive
   It is unreliable 
   I have tar 2 GB of files to the tape and backup 
   1,400 of 1,600 files.  It skip files (200).
   I have playing with this for 5 months.  It does not works relialy.
   You better check your tape carefully.
3) cpio
    It skip files also.
4) printer attached to RS 422 port
   forget it.  It dies every 4 hours.  The queue daemon went out to lunch
   regularly.
   We used LPD print server software from FTP software running on PC
   as print server and use remote print queue.
5) Rs/6000 cannot telnet to SCO Xenix
   But can rlogin to SCO Xenix
6) Increase your process limit
   your need to edit /usr/include/sys/limits.h
   CHILD_MAX to increase your number of process allowed per user id
   in ksh 40 is too small for root
   chdev -l sys0 -A maxuproc has no effect in ksh
7) There is some strange limit to number of device attached to SCSI card
   Basically, if you have internal device attached to SCSI adapter
   you can only have one or two extenal device per adapter.  It applies in
   540 and 530 also in addition to 320.
8) inetd
   I let my rs/6000 PING EACH OTHER every hour.  That seems to be the only
   way to keep it running constantly.
9) PC/TCP telnet to RS/6000
   If the session did not terminate gracefully, it drive RS/6000 nuts.
   You will see sar command show system % time > user % time.
   ps -ef will show pts/? session that did not show up in w command
   ps au will show the session that eat away your CPU time.
   Call the user, he/she will say I am not login.
   kill the session, things will go back to normal.
10) RS/6000 (token ring TCP/IP) connect to Cisco
    Need to define static ARP route in Cisco to RS/6000 or else the link
    is not stable.
I will post more problem as I discover them.
Seng C, Gan
Unix SysAdm
Star Enterprise
Tel:(713)874-7816
Call me if you know any more problem about TCP/IP that I am not aware of.