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From: erik@mpx2.UUCP (Erik Murrey)
Newsgroups: comp.unix.questions,comp.unix.microport
Subject: Re: dump/restore
Summary: which "backup" is best?
Keywords: cpio is not a real backup program
Message-ID: <262@mpx2.UUCP>
Date: 29 Oct 88 16:14:59 GMT
Article-I.D.: mpx2.262
References: <178@celerity.UUCP> <229@dcs.UUCP> <180@celerity.UUCP>
Organization: MPX Data Systems, Inc. ,  Wayne, PA
Lines: 32


All of this tar/cpio/dump discussion raises some questions for
me:

Sys-V tar doesn't copy directory permissions (or even directory
entries!) to the tape.  This means that empty directories don't
get backed up and permissions get guessed during a restore.  This
stinks.  (I know BSD's tar does this correctly)

I like cpio becuase it dumps everything to tape.  Even directories
and special files like named pipes, etc.  I does not, however, allow
you to split the backup across several tapes (or disks).  This
is a big loss for people without tape drives (me).

Dump/restore is very quick, and it backs up everything, but I have
a few questions:   It seems to dump the entire filesystem, including
the superblock/inode dumps.  It also seems to me that it dumps
disk blocks in order of the disk itself, rather than the order of the
file.  This means that restoring a filesystem will *not* reduce
the fragmentation.  (Which is often why I backup/restore in the
first place.)  Does it also require the exact same filesystem
to by restored on?  If this is so, then I can't use dump/retore to
expand a full filesystem.

The docs I have for dump/restore don't explain details like
this to me.  Please fill me in!

---
Erik Murrey
MPX Data Systems, Inc.
erik@mpx1.UUCP
...!{bpa,spl1,cbmvax,vu-vlsi}!mpx1!erik