I've upgraded our backup server from Ubuntu 16.04.5 to 18.04.1. This gave us amanda 3.5.1-1build2 (before upgrade: 3.3.6-4.1).
Our daily routine is: amdump to disk amvault to tape library amcheckdump the tapes The new amcheckdump 3.5.1 is giving us trouble: It's using 100% cpu and is very slow. The amcheckdump.TIMESTAMP.debug log is getting huge. Looks like the old amcheckdump 3.3 did send the tar stdout to XferDestNull: Thu Jan 24 20:07:18 2019: thd-0x2156600: amcheckdump: Starting <Xfer@0x3455b00 (<XferSourceRecovery@0x32a5bf0> -> <XferFilterProcess@0x32a65b0> -> <XferFilterProcess@0x32a6240> -> <XferDestNull@0x32a68a0>)> while the new amcheckdump 3.5 does read the stdout and writes it to the debug log: Wed Jan 30 17:03:57.821371099 2019: pid 30171: thd-0x563e2ee8de00: amcheckdump: Starting <Xfer@0x563e314e5340 (<XferSourceRecovery@0x563e30e83240> -> <XferFilterProcess@0x563e311bfac0> -> <XferFilterCrc@0x563e311c00d0> -> <XferDestApplication@0x563e311ccbf0>)> [...] Wed Jan 30 17:09:29.979934691 2019: pid 30171: thd-0x563e2ee8de00: amcheckdump: /usr/lib/x86_64-linux-gnu/amanda/perl/Amanda/Restore.pm:582:info:4900018 application stdout: ./usr/src/linux-headers-4.15.0-44-generic/include/config/slicoss.h Wed Jan 30 17:09:29.992425948 2019: pid 30171: thd-0x563e2ee8de00: amcheckdump: /usr/lib/x86_64-linux-gnu/amanda/perl/Amanda/Restore.pm:582:info:4900018 application stdout: ./usr/src/linux-headers-4.15.0-44-generic/include/config/slip.h Wed Jan 30 17:09:30.004920337 2019: pid 30171: thd-0x563e2ee8de00: amcheckdump: /usr/lib/x86_64-linux-gnu/amanda/perl/Amanda/Restore.pm:582:info:4900018 application stdout: ./usr/src/linux-headers-4.15.0-44-generic/include/config/slub.h This is also the reason for the high cpu usage: amanda does read the application stdout via POSIX::read($fd, $b, 1) in Amanda/Restore.pm. Reading one byte at a time is expensive. Could someone please provide a patch which gives us the old amcheckdump behaviour (sending the tar listing to XferDestNull)? Thanks in advance, Joerg
