Thanks for the suggestion. Your "pipeline assumption" was correct.
I have an Exabyte SCSI-3 tape drive which is faster than most DAT drives, so it is worth it to see if I can get "encrypted backups" to work easily enough. Next - I will be experimenting with encrypting backups via ISO (CD images), and will probably need a similar pipeline. Bob Dunlop wrote: > Hi, > > On Fri, Sep 08 at 09:54, User1001 wrote: >> When attempting to back up a filesystem with GPG to encrypt the stream, >> the result (so far) has always been: >> >> gpg: /dev/sa0: write error: Invalid argument >> gpg: iobuf_flush failed on close: file write error >> >> no matter what method (dump, dd, tar, etc.) was used to create the "dump >> stream". It appears to occur only at the end of the "dump stream". >> Different options for dd (conv=notrunc conv=osync) don't make any >> difference. Using the "--batch" option for GPG doesn't make any difference. >> >> Is there a way to correct this (without creating any new files)? > > It's difficult to know what you're actually doing without some example > of the command pipeline you're using. > > I'm guessing it's something like this: > > dd,tar,etc to create archive | gpg -e -r ID > /dev/sa0 > > If so the problem is that many tape device drivers are not the friendliest > for standard applications to write to. Drivers tend to be fussy about > block sizes, have very primative seek capability if any and do strange > things at EOF. > > The trick I'd suggest is to use dd on the output side of gpg as a buffer > for the tape mechanism. You should need to do no conversion other than > possibly pad the final block. I'd also make sure the tape is rewound > before you start. Hence: > > mt -f /dev/sa0 rewind > dd,tar,etc to create archive | gpg -e -r ID | dd bs=4096 of=/dev/sa0 > conv=sync > > > ps. This is from memory. The last tape drive I possess has been sitting > in the recycle/spares pile for several years now. _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users
