Alzheimer's Syndrome

[Albert Hybl Dept of Biophysics SM]

Mbph is using news_version "B 2.11 12/1/87" at patch_level 14;
it is a leaf node from umbc3.  Mbph is an AT&T 3B2/400 computer
runing version 3.0 release 2 UNIX.  It has two 72MB hard disks
partitioned into file systems /, /usr, /usr2, /usr3 and /usr4.
Mbph receives compressed news batches twice a day.  Expire is run
late each evening about an hour before polling our feed.  We do
not take a full feed; only comp, news, sci, bionet and a few other
small groups.  The news is retained 7 days.

Everything seemed to be runing properly until one morning
the following was scrolled on the screen of the console terminal:
"Notice: Out of inodes on integral hard disk 1, partition 10."
A df command showed that this was /usr4 and that there was only
1 inode available.  It also showed that there were about 30000
blocks of disk memory available; each block can hold 1024 bytes.
/usr4 is dedicated to the spool containing directories for the
news groups.  (The batched news segments are received by
/usr/spool/uucp/umbc3.)  /usr4 can hold a total of 49572 blocks
and 6217 inodes.

The du -a /usr4 | wc commands showed that slightly more that
3000 inodes were actually being used.  The /usr4 file system
was showing symptoms of Alzheimer's disease:-)  I used the
fsck command to cure the problem.  Unfortunately, it was short
lived--the patient has suffered at least two relapses.

I have followed some of the activities during the transfer and
processing of news batches.  While the communication link is
active as shown by using the uustat -q command, directory
/usr/spool/uucp/umbc3 is slowly growing by adding X.* and D.*
files while file TM.* is receiving a new file from the remote
feed.  After the communication link is disconnected, the X.*
files are processed and the news files added to /usr4.

The df command showed /usr adding freed blocks and inodes to its
free lists while the block/inode counts were decreasing on
/usr4.  I have watched two news transfers in this way.  During
one of them the inode count for /usr4 suddenly jumped from about
2875 to 0!  The following information shows a few lines
of output produced after the jump by the df commands and
a ps -ef command (edited to show only the germane processes).

------------------------------
/usr4     (/dev/dsk/c1d1sa ):    28470 blocks        1 i-nodes
/usr4     (/dev/dsk/c1d1sa ):    28464 blocks        0 i-nodes
/usr4     (/dev/dsk/c1d1sa ):    28470 blocks        1 i-nodes
     UID   PID  PPID  C    STIME TTY      TIME COMMAND
    uucp  7919     1  0 02:48:57 ?        0:10 UUXQT -sumbc3 
    uucp  8605  7919  0 03:16:12 ?        0:00 sh -c PATH=/bin:/usr/bin:/usr/lbin  LOGNAME=uucp UU_MACHINE=umbc3 UU_USER=root 
    uucp  8606  8605 21 03:16:13 ?        0:02 rnews 
    uucp  8607  8606 14 03:16:14 ?        0:04 compress -d 
    uucp  8635  8606 40 03:17:03 ?        0:01 rnews 
/usr4     (/dev/dsk/c1d1sa ):    28470 blocks        1 i-nodes
/usr4     (/dev/dsk/c1d1sa ):    28468 blocks        0 i-nodes
/usr4     (/dev/dsk/c1d1sa ):    28470 blocks        1 i-nodes
------------------------------

QUESTIONS:  Has anyone observed this behavior before?
Is there a known bug in news2.11 or SysV software?  
Is there a patch for this problem?  Please send a copy to me.
Can anyone suggest some automated ways to monitor the news
transfer to located the source of the problem?
Do you have a shell or C program that can help with this task?

PLEASE: Because we are losing some of our news, reply using e-mail.
Thank you in advance.
                    A. Hybl


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Albert Hybl, PhD.              Office UUCP: uunet!mimsy!mbph!hybl
Department of Biophysics       Home   UUCP: uunet!mimsy!mbph!hybl!ah
University of Maryland                Cosy: ahybl
School of Medicine
Baltimore, MD  21201                 Phone: (301) 328-7940 (Office)
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