[comp.unix.questions] ISC 386/ix sysadm filemgmt facilities & cpio

rob@phavl.UUCP (Robert Ransbottom) (08/05/89)

I would like to alter the "sysadm filemgmt" facilities on 
Interactive's 386/ix rel. 2.0.1 (2.0.2) to allow the use 
of the 'C' option to "cpio".  Ideally "slow mode" would
be an available user option.

Any help appreciated.

Incidentally -- on a Dell System 310 (20Mhz & 4Meg) under 386/ix
r2.0.1 with a 60Meg Wangtek -- empirical testing with

   "date && 
    cat $FileListFile | cpio -$Opts <|> /dev/tape && 
    date  # $FileListFile equates to 45Meg"

yields the following:

 $Opts                  Megs/Minute
 -ovcC262144            0.42
 -ovcC102400            3.18
 -itvC102400            3.15
 -ovcB                  1.05
 -itvB                  1.15
 -itv                   0.64
-- 
 ...!uunet!phavl!rob              Robert Ransbottom

johnl@esegue.uucp (John Levine) (08/05/89)

In article <266@phavl.UUCP> rob@phavl.UUCP (Robert Ransbottom) writes:
>I would like to alter the "sysadm filemgmt" facilities on 
>Interactive's 386/ix rel. 2.0.1 (2.0.2) to allow the use 
>of the 'C' option to "cpio".  Ideally "slow mode" would
>be an available user option.

All of the sysadm menus are implemented as shell scripts, which are not hard
to change.  The backup command is in /usr/admin/menu/filemgmt/backup, and it
calls /etc/savecpio, which calls /usr/lbin/ncpio, which is a stub that runs
cpio.  It is a moment's work to add the -C flag, probably in /etc/savecpio,
and not much more than that to add an extra question in filemgmt about
whether to run fast or slow.

By the way, in most versions of cpio including 386/ix's, the buffer size it
uses is 10 times bigger than what you ask, e.g. "-C 10240" uses a buffer of
size 102400.  I had lots of mysterious hangs until I realized that when I
asked for a 512000 byte buffer, I was actually asking for a 5 meg buffer,
and it's hard to lock that in core on a 4 meg machine.
-- 
John R. Levine, Segue Software, POB 349, Cambridge MA 02238, +1 617 492 3869
{ima|lotus}!esegue!johnl, johnl@ima.isc.com, Levine@YALE.something
Massachusetts has 64 licensed drivers who are over 100 years old.  -The Globe

debra@alice.UUCP (Paul De Bra) (08/07/89)

In article <266@phavl.UUCP> rob@phavl.UUCP (Robert Ransbottom) writes:
}...
}Incidentally -- on a Dell System 310 (20Mhz & 4Meg) under 386/ix
}r2.0.1 with a 60Meg Wangtek -- empirical testing with
}...
}
}yields the following:
}
} $Opts                  Megs/Minute
} -ovcC262144            0.42
} -ovcC102400            3.18
}...

Yep, don't forget the bug in cpio which multiplies the buffer size by
10.
102400 gives you 1024000 bytes, a nice size for smooth transfer.
262144 gives you 2621440 bytes, which, after adding kernel exceeds
your physical memory. As a result your system starts paging a lot,
probably on the same disk cpio is trying to read from...

Paul.
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