Bscan will not help. Eric is correct: you can't recover an overwritten tape using normal tape drive software because it will not allow you to read beyond the end of the last-written data.
__Martin >>>>> On Mon, 25 Mar 2024 19:15:50 +0200, Pedro Oliveira said: > > Please could try to use Bacula Volume utility tool bscan > > https://www.bacula.org/2.4.x-manuals/en/main/Volume_Utility_Tools.html > > Create your WiseStamp email signature > <https://www.wisestamp.com/lp/promo/professional-email-signature?utm_source=promotion&utm_medium=signature&utm_campaign=create_your_own&srcid=> > > [image: __tpx__] > > > > Dedy Yohann <y.d...@cinematheque.fr> escreveu em seg., 25/03/2024 às 19:12 : > > > So I managed to relabel the tape, using the "btape labe" command. But as > > you all implied, that's unfortunately not enough. > > > > When I run bextract, no files are restored and the command ends after a > > couple of seconds > > Here's the log (the volume ID is PAT031L7) > > > > # bextract -c /etc/bacula/bacula-sd.conf -t -V PAT031L7 Drive-0 > > /tmp/restore/ -v > > bextract: butil.c:292-0 Using device: "Drive-0" for reading. > > 25-Mar 18:01 bextract JobId 0: No slot defined in catalog (slot=0) for > > Volume "PAT031L7" on "Drive-0" (/dev/nst0). > > > > 25-Mar 18:01 bextract JobId 0: Cartridge change or "update slots" may be > > required. > > 25-Mar 18:01 bextract JobId 0: Ready to read from volume "PAT031L7" on > > Tape device "Drive-0" (/dev/nst0). > > > > 25-Mar 18:01 bextract JobId 0: End of Volume "PAT031L7" at addr=0:0 on > > device "Drive-0" (/dev/nst0). > > 0 files restored. > > > > > > I am somewhat familiar with the disk recovery for block devices with dd. > > I might give this a try after we figure if a recovery is absolutely needed. > > > > Thanks for the hints > > > > > > Yohann DEDY > > ------------------- > > Tél: 06 23 91 46 00 > > ------------------------------ > > *De :* Rob Gerber <r...@craeon.net> > > *Envoyé :* lundi 25 mars 2024 16:35 > > *À :* Pedro Oliveira <oliveira...@gmail.com> > > *Cc :* Dedy Yohann <y.d...@cinematheque.fr>; bacula-users < > > bacula-users@lists.sourceforge.net> > > *Objet :* Re: [Bacula-users] Mistakenly erased label headers from LTO > > with btape test / need help to salvage content > > > > Standard data recovery processes are to take a bit for bit image of the > > troubled media, them attempt all recovery against a copy of the image. This > > process is used in disk recovery for block devices but I think it could > > apply in your case also. > > > > At minimum, I would write some data to a scratch tape with bacula (at > > least 20gb or something somewhat substantial consisting of known files > > which you have hashed so you can verify the success of the recovery), > > repeat the previous mistaken run of 'btape test' with reasonably quick > > cancellation (but not too quick as to be overly optimistic!), then attempt > > recovery. > > > > How recovery is done in this case is something I'm not super familiar > > with. As suggested by Pedro, maybe label + bextract (spelling uncertain, > > check bacula bin folder)? When dealing with a tape whose data is not in the > > bacula catalog we typically want to run bscan, but I don't know if it will > > handle this case well. > > > > The wisest case may be to set this tape aside and do a new full backup. If > > a recovery is needed then you can attempt recovery of data from this tape. > > If no recovery is ever needed, then no problem. > > > > > > > > Robert Gerber > > 402-237-8692 > > r...@craeon.net > > > > On Mon, Mar 25, 2024, 10:25 AM Pedro Oliveira <oliveira...@gmail.com> > > wrote: > > > > try to label again the tape and then try to use bexcrtac > > > > Create your WiseStamp email signature > > <https://www.wisestamp.com/lp/promo/professional-email-signature?utm_source=promotion&utm_medium=signature&utm_campaign=create_your_own&srcid=> > > > > [image: __tpx__] > > > > > > > > Dedy Yohann <y.d...@cinematheque.fr> escreveu em seg., 25/03/2024 às > > 17:15 : > > > > Dear bacula community, > > I made a mistake today while making maintenance tasks. > > > > I unintentionaly ran the "btape test" command on a LTO cartidge that was > > already labeled and assigned to our main backup pool. > > > > When I realized data was written on the tape after a couple of seconds, I > > stopped the operation (ctrl-c) in panic... > > Unfortunately the evil was already done, now when I try to restore data > > from this volume, the cartidge is correctly loaded in the drive (barcode > > checked by the autochanger) but I get this error once data is read from the > > tape : > > > > bacula-sd JobId 425: Warning: acquire.c:279 Read acquire: Could not > > unserialize Volume label: ERR=label.c:987 Expecting Volume Label, got FI=0 > > Stream=0 len=64412 > > > > Is there a way to manually restore the content of the tape or force the > > relabelling of the tape without erasing the content of the cartidge? > > > > Thanks in advance for your suggestions, > > > > Yohann > > > > Bacula version : 9.6.7 > > Debian 10 (Buster) > > Kernel 4.19.0-25-amd64 > > > > > > _______________________________________________ > > Bacula-users mailing list > > Bacula-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/bacula-users > > > > _______________________________________________ > > Bacula-users mailing list > > Bacula-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/bacula-users > > > > > _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users