Dear Maintainer, Deb12 has dump 0.4b47-4, and Deb13 has currently 0.4b49-2. I'm running an automated backup script for years: https://github.com/PoC-dev/backup Scenario: Dump written on Deb12 with dump -0a -b 256 -f - /dev/... (I'm using 256k blocks for performance reasons, and because I write those dump files to tape with dd.) Then access such a file locally with restore -i -b 256 -f ... restore > ver verbose mode on restore > ex Extract requested files You have not read any volumes yet. Unless you know which volume your file(s) are on you should start with the last volume and work towards the first. Specify next volume # (none if no more volumes): 1 short compressed block: 262148 expected: 122091355 decompression error, block 262145: data error Tape decompression error while skipping over inode 5125 continue? [yn] y Incorrect block for <name unknown> at 3255 blocks Incorrect block for <name unknown> at 3256 blocks Incorrect block for <name unknown> at 3257 blocks ... Incorrect block for <name unknown> at 3414 blocks short compressed block: 262148 expected: 1835599 decompression error, block 262401: length mismatch Incorrect block for <name unknown> at 3415 blocks Incorrect block for <name unknown> at 3416 blocks Incorrect block for <name unknown> at 3417 blocks ... Incorrect block for <name unknown> at 6394 blocks Incorrect block for <name unknown> at 6395 blocks Segmentation fault The only way to restore files from dumps is to install the old dump package.
On Tue, 02 Jun 2026 11:34:29 +0200, Patrik Schindler writes: thank you for the bug report; i'll try to find some time this weekend to dig deeper into this. regards az
tags 1138683 + moreinfo unreproducible severity 1138683 normal thanks On Tue, 02 Jun 2026 11:34:29 +0200, Patrik Schindler writes: ... i haven't been able to fully or exactly duplicate your problem :-( (i've tried all kinds of invocations and variants with 2gb of plain bookworm chroot as backup source...) without -b 256 none of the backups i've done with the b47 dump showed any problems when restoring with the b49 version. (if we can't find a better solution, could you have a check if omitting the blocksize does provide a workaround for your setup?) with -b 256, the b49 version threw an 'unsupported compression type 7' error...but that's as close as i could get to the showstopper you reported. slightly better news is that i also tested restoring with the version in testing and unstable, 0.4b54-1, and that restored older backups with or without -b just fine. 0.4b54-1 has just been accepted into stable-backports: could you please have a go at installing that (once it hits the mirrors) and test restores with that version? regards az
Oops, sorry, I've missed your reply. Will test and give you feedback! :wq! PoC