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From: nagy%bsndbg.hepnet@LBL.ARPA.UUCP
Newsgroups: mod.computers.vax
Subject: SYSE root
Message-ID: <8702281740.AA12366@ucbvax.Berkeley.EDU>
Date: Sat, 28-Feb-87 11:40:26 EST
Article-I.D.: ucbvax.8702281740.AA12366
Posted: Sat Feb 28 11:40:26 1987
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>    I have a question that I was hoping someone could answer for me.
>It concerns the SYS0 and SYSE.SYSCOMMON directories on my system disk.
>Both of these directories are identical, I tried deleteing some files from
>one and they were gone from the other also.....bad mistake! I would like
>some information on whats going on here, can I do away with it, what
>purpose it serves, where I can find more information on it in the manuals.
     
The SYSE root is currently reserved by Digital to hold a "copy" of
Standalone Backup.  Thus you can quickly boot a copy of Standalone Backup
to allow you to save/restore disks (you can save the system disk using
the SYSE S/A Backup, but you can not restore the system disk using it!).
Certainly faster than loading S/A Backup off of floppies or TU58's.

The STABACKIT.COM procedure sets up the SYSE root, but rather than
making copies of the files necessary for S/A backup, it adds a synonym
directory entry.  You will find, if you do DIRECTORY/FULL, that the
SYSCOMMON.DIR entry in [SYSE] has the same file number as V4COMMON.DIR.
Now, the [V4COMMON] tree is the common system tree with the files which
are common to all the system roots on a common system disk.  Deleting
anything from [SYSE.SYSCOMMON] is IDENTICAL to deleting from [V4COMMON...].

The [SYSE.SYSEXE] directory contains separate files needed by S/A Backup
and not common with the other system roots.