linda@cc.brunel.ac.uk (Linda Birmingham) (08/08/89)
I'm trying to validate dump tapes. I liked someones idea of trying to restore the last file on the tape. The question was...how do I know which is the last file. The restore t gave me a list of inodes and it seemed that things were dumped in inode order. Hurray ! Just restore the highest inode...unless the highest inode refers to a directory. I do not want to restore the whole damn file-system. How can I find out if this inode refers to a directory or file on the dump tape ? Thanks, Linda. -- Brunel University, Uxbridge, Middlesex, England. janet: linda@uk.ac.brunel.cc | :-) uucp:...ukc!cc.brunel!linda |
jeffrey@algor2.uu.net (Jeffrey Kegler) (08/12/89)
In article <794@Terra.cc.brunel.ac.uk> linda@cc.brunel.ac.uk (Linda Birmingham) writes: >I'm trying to validate dump tapes. > >I liked someones idea of trying to restore the last file on the tape. > I have always simply reread the tape's table of contents. Does anyone have experience of this failing? "Fail" is defined here as a successful read of the table of contents where the tape's contents were bad. -- Jeffrey Kegler, Independent UNIX Consultant, Algorists, Inc. jeffrey@algor2.ALGORISTS.COM or uunet!algor2!jeffrey 1762 Wainwright DR, Reston VA 22090
jfh@rpp386.Dallas.TX.US (John F. Haugh II) (08/13/89)
In article <1989Aug12.063242.544@algor2.uu.net> jeffrey@algor2.UUCP (Jeffrey Kegler) writes: >I have always simply reread the tape's table of contents. Does anyone >have experience of this failing? "Fail" is defined here as a >successful read of the table of contents where the tape's contents >were bad. Yes, too many times to count. In particular, I've gotten 'missing address/header block' errors from dump [ restor ] quite often on tapes which tested quite okay. I'd love to catagorically state this is a bug in dump, but I've never bothered to track it down since cpio works ... -- John F. Haugh II +-Quote of the month club: ------------ VoiceNet: (512) 832-8832 Data: -8835 | "Chocolate Teddy Grahams are just InterNet: jfh@rpp386.cactus.org | reincarnated Space Food Sticks." UUCPNet: {texbell|bigtex}!rpp386!jfh +------------ -- Richard Sexton ---
davidsen@sungod.crd.ge.com (ody) (08/15/89)
At a minimum I would read the T/C and dd the whole dump to /dev/null
to be sure the tape can be read. The Xenix restore has a C option which
checks the tape byte for byte against the filesystem. Slow, but faster
than recreating several MB of lost data.
bill davidsen (davidsen@crdos1.crd.GE.COM)
{uunet | philabs}!crdgw1!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -mebob@wyse.wyse.com (Bob McGowen Wyse Technology Training) (08/15/89)
In article <1989Aug12.063242.544@algor2.uu.net> jeffrey@algor2.UUCP (Jeffrey Kegler) writes: >In article <794@Terra.cc.brunel.ac.uk> linda@cc.brunel.ac.uk (Linda Birmingham) writes: >>I'm trying to validate dump tapes. >> >>I liked someones idea of trying to restore the last file on the tape. >> > >I have always simply reread the tape's table of contents. Does anyone ---deleted--- dump under XENIX (also backup -- hard linked names) puts the table of contents first on the tape, followed by the files. This means that if I read only the table of contents with dumpdir, I do NOT test the integrity of the actual files on the rest of the tape. I do not know if this "feature" is the same on all systems? I have used dd to read the entire tape to be sure it is at least readable but this does nothing in terms of checking the logical structure created by the dump. Restoring the last file on the tape will certainly prove that it is good and may possibly validate the rest of the tape since restore has to find the file, which it would presumably do by reading the tape. Perhaps there is some way to generate a checksum on the disk to compare with a checksum from the tape? Bob McGowan (standard disclaimer, these are my own ...) Customer Education, Wyse Technology, San Jose, CA ..!uunet!wyse!bob bob@wyse.com
richl@penguin.USS.TEK.COM (Rick Lindsley) (08/22/89)
In article <794@Terra.cc.brunel.ac.uk> linda@cc.brunel.ac.uk (Linda Birmingham) writes:
I'm trying to validate dump tapes.
I liked someones idea of trying to restore the last file on the tape.
The question was...how do I know which is the last file.
restore tv will print out things like
dir 2 .
dir 1536 ./etc
leaf 1630 ./etc/dumpdates
A "dir" is obvious; a "leaf" is really just "not-dir". A simple awk
script will then help you here:
restore tv | awk '$1 == "leaf" {if (ino < $2) file = $3;} END {print file}'
This fails if that last filename has white space in it.
Rick