reece%nadc@sri-unix.UUCP (01/12/84)
We recently ran into what looks like a bug but I've not seen anyone mention it. I thought someone might recognize it: We have multi-volume dumps which we need to occasionally do restores of one or two files. When the file(s) are on the first volume it does it OK, but when they are on any of the other volumes, the program seems to just quit. We mount the first tape and do a "restor -x"; the program says that the file is not on that volume and to mount another volume. We mount the second (or third) tape and give "restor" the appropriate volume number. Restor seems to read a block or two off the tape then quit. Also, are you supposed to be able to do a dumpdir on all volumes of a multi-level dump or just the first? The first is all we can do one on. Thanks for any help or enlightenment. Jim Reece REECE@NADC
ALMQUIST@SU-SCORE.ARPA (01/14/84)
From: Philip Almquist <ALMQUIST@SU-SCORE.ARPA> Jim, I'm not sure, but what you're describing sounds a whole lot like what happens if you try to restore a file that's not in the dump at all. If the file is included in the dump, restor will tell you its i-node number when it reads through the first volume of the tape. If the file is not in the dump, restor will not tell you the i-node number but will still ask you to mount another volume! When you mount the other volume, the restore will terminate if the file was not included in the dump. Or at least that is my recollection of the situation, from the one time I ever tried to do a restor on a UNIX system... Perhaps there is a wizard out there who can explain why this is so? Philip -------
thomas@utah-gr.UUCP (Spencer W. Thomas) (01/16/84)
Restor will "give up" on a tape if the tape starts at an inode larger than the one requested. I have sometimes seen a case where dump apparently "forgot" to save some files - I attribute this to dumping active file systems, but I'm not sure. You can only do a dumpdir with the first volume mounted because ALL the directory and filename information is at the beginning of the first volume. =Spencer
jlh%amsaa@sri-unix.UUCP (01/17/84)
From: John Halliburton (SSAO) <jlh@amsaa>
Unless you are using an acient version of bmd unix...you probably should
be using 'restor tv' to print your directory instead of 'dumpdir'. To my
knowledge the whole directory is put on the first tape. We have not experienced
the exact same problem, however we did discover that unless you are restoring
intirely from 0 level dumps, restore puts back deleted files. Which can be
real fun if you are running on limited file space. Please forward any other
info/ problems you have had since we are very interested in any 'flakes' in
dump or restor.......if you can't trust your backup utility, why bother to
waste all those tapes...
john halliburtongwyn%brl-vld@sri-unix.UUCP (01/17/84)
From: Doug Gwyn (VLD/VMB) <gwyn@brl-vld> Personally I back up my files with CPIO.
ron%brl-vgr@sri-unix.UUCP (01/19/84)
From: Ron Natalie <ron@brl-vgr> Sorry, but dump tapes know nothing about directories. They store inodes. There is no guarantee about the location of anything. -Ron
jlh%amsaa@sri-unix.UUCP (01/19/84)
From: John Halliburton (SSAO) <jlh@amsaa>
i'm sorry too ron...somethimes you guhru's ought to come down the hill to
where we "line" folks labor. We customarily do a 0(zero) level dump on
the file system where the user directories are. (since they are most frequently
changed). This takes two tapes. After mounting and writing the second tape
using 'dump'. It is absolutely necessary to remount the first tape to get
a 'restor tv | print' (the old dumpdir). The drive appears to read about the
first 15 or 20% of the tape and rewind. Parse it anyway you want but if that
is not the front of the first tape, I don't know what it is. Feel free to
come down to vax caverns any day around 4pm (1600) to watch this mysterious
project.
johnguy@rlgvax.UUCP (Guy Harris) (01/20/84)
The V7 dump and its descendants (S3 dump, 4.1BSD dump, 4.2BSD dump) *do* know
the difference between directory inodes and non-directory inodes; they first
dump the directory inodes and then dump the non-directory inodes. As such,
"restor" can - and does - build a model of the portion of the directory
hierarchy which was dumped onto that tape (if any file was dumped, it dumps
all the directories leading up to that file whether they changed since the
dump date or not), which is how it can find files by name.
Guy Harris
{seismo,ihnp4,allegra}!rlgvax!guy