[comp.unix.microport] Of Large Mailboxes, Elm, and uPort

tkevans@fallst.UUCP (Tim Evans) (02/20/89)

This is to document a recent experience, and to ask for suggestions for
preventing its recurrence.

First, the nuts-and-bolts:  Microport Sys V/AT, Version 2.4, running on
an AT clone with a 40-meg hard disk (brand names irrelevant); Elm 2.1.

I just returned from a brief vacation and found my mailbox fairly full
(90-odd messages.)  Elm attempted to create its temporary copy of the
mailbox file, but apparently ran out of space in /tmp.  Only the first
half-dozen (the most recent) messages showed any content on Elm's listing;
the rest showed _zero_ line-lengths.  After reading and deleting the first
couple of messages, attempts to read the zero-length messages resulted only
in a blank screen.  When I exited Elm, it told me it was deleting a couple
of messages and retaining 80-some.  When I subsequently went back into
Elm to read mail again, there were *N*O* messages!  Everything had dis-
appeared.  /usr/mail/myname was also empty!

(Anyone who sent me important 8-:) mail during the period 2/15-2/18 might
want to send it again.)

Now, I used uPort's "easyinstall" (no smirks, please--I saw no reason to
do otherwise at install time) script in installing
SysV/AT.  This script has default file system sizes.  In my case (with
the 40-meg disk), it results in file systems as shown below (output of
'df -t'):

/usr      (/dev/dsk/0s2):    18614 blocks    2345 i-nodes
                   total:    56518 blocks    5648 i-nodes
/         (/dev/dsk/0s0):     9964 blocks    1638 i-nodes
                   total:    20000 blocks    2000 i-nodes

As can be seen, the root partition was set up for 20000 blocks, about
half of which is taken up at any given time.  This setup seems to
work fine for most things, but obviously not for the particular situation
of having a large mailbox.

I know that I can reinstall SysV/AT and make changes in the file system 
sizes from the default.  Can _Elm_ be configured to put its temporary
mailbox in the /usr partition, though?  If so, how?

Which would be the better approach?  Thanks.
-- 
UUCP:  ...!{rutgers|ames|uunet}!mimsy!arinc!wb3ffv!fallst!tkevans
INTERNET:  tkevans%fallst@wb3ffv.ampr.org
OTHER: ...!attmail!fallst!tkevans
Tim Evans  2201 Brookhaven Court, Fallston, MD  21047   (301) 965-3286

frankb@usource.UUCP (Frank Bicknell) (02/21/89)

In article <500@fallst.UUCP>, tkevans@fallst.UUCP (Tim Evans) writes:
> I just returned from a brief vacation and found my mailbox
> fairly full (90-odd messages.)  Elm attempted to create its
> temporary copy of the mailbox file, but apparently ran out
> of space in /tmp.  Only the first half-dozen (the most
> recent) messages showed any content on Elm's listing; the
> rest showed _zero_ line-lengths.  After reading and deleting

I have had a similar, but not quite so destructive
experience under Xenix 2.3.1 (386, but code compiled with
286 compiler).  I doesn't seem to have anything to do with
how much space is available for a /tmp/... file.  My error
ocurrs when the message counter passes about 140 or so (I
think it is dependant upon the size of the messages,
however).  The error message reads: 

Segment Violation Signal!



Emergency Exit Taken!  All Temp Files Intact!


(once again: thank you, Intel, for your gift to the world of
segmented memory.... oops, I'm forgetting myself...)

As it turns out, editing the mailbox with vi to split it up into
managable pieces "fixes" the problem, and nothing is lost.

Anyone else had the same problem?
-- 
Frank Bicknell; 1405 Main St, Ste 709; Sarasota, FL 34236-5701
killer!usource!frankb

steve@raspail.UUCP (Steve Schonberger) (02/22/89)

In article <500@fallst.UUCP>, tkevans@fallst.UUCP (Tim Evans) writes:
> I just returned from a brief vacation and found my mailbox fairly full
> (90-odd messages.)  Elm attempted to create its temporary copy of the
> mailbox file, but apparently ran out of space in /tmp.

[...]

> When I subsequently went back into
> Elm to read mail again, there were *N*O* messages!  Everything had dis-
> appeared.  /usr/mail/myname was also empty!

> I know that I can reinstall SysV/AT and make changes in the file system 
> sizes from the default.  Can _Elm_ be configured to put its temporary
> mailbox in the /usr partition, though?  If so, how?

I had that problem on other machines, and my solution was to partition
so that there was just enough room on root for the stuff that has to be
there, and a very small amount of temp space.  Then set things up like
this:

On the root partition:
/tmp		symbolic link to /usr/tmp
/usr		mount point for /usr partition
/usr/tmp	tmp space for when /usr partition isn't mounted

On the /usr partition:
/usr/tmp	main tmp space area

This keeps you from running out of space unless your /usr is full too,
in which case you have other problems to worry about besides not being
able to read mail.

	Steve Schonberger
	steve@raspail.cdc.com	...!uunet!rosevax!shamash!rapail!steve

chip@ateng.ateng.com (Chip Salzenberg) (02/24/89)

According to frankb@usource.UUCP (Frank Bicknell):
>My error occurs when the message counter passes about 140 or so...
>The error message reads:
>
>Segment Violation Signal!
>Emergency Exit Taken!  All Temp Files Intact!

This was a bug only for the '286.  (What else is new?)  It has been fixed
in 2.2 dev.
-- 
Chip Salzenberg             <chip@ateng.com> or <uunet!ateng!chip>
A T Engineering             Me?  Speak for my company?  Surely you jest!
	  "It's no good.  They're tapping the lines."