Not sure if this is helpful, but the output of strace shows it stuck in some timeout loop:
stat("/var/lib/backuppc/cpool/7e/4e/7e4e672bd913eadb030d0670aecb6607", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/3a/e2/3ae2b652d5cda073df7af75d3bb3ecdf", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/40/0e/400e7dbed090db12fb6594f1d995453c", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/4e/4c/4e4ce2f7453a6b8285ea282dd4ca6bb3", {st_mode=S_IFREG|0444, st_size=190164, ...}) = 0 openat(AT_FDCWD, "/var/lib/backuppc/cpool/4e/4c/4e4ce2f7453a6b8285ea282dd4ca6bb3", O_RDONLY) = 5 read(5, "\327^\354\275y\274OU\374\377\273\327\376\234c\36\216cH\"\307P\35\241\216)ceJTB\224"..., 1048576) = 190164 lseek(5, 4294963247, SEEK_CUR) = 4295153411 close(5) = 0 stat("/var/lib/backuppc/cpool/be/18/bf198d5310385ead4db2766a72b9d4ba", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/f0/d4/f0d424b17f2f7f3433dc5342914b34e2", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/b8/d2/b8d2df95db0c551243995e9c21cc25d8", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/1e/48/1e48b92e7b83c639c0b9c91bd1dea36b", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/f4/12/f4132159f1faa93cc13f97b5c68e50b7", {st_mode=S_IFREG|0444, st_size=1891951, ...}) = 0 openat(AT_FDCWD, "/var/lib/backuppc/cpool/f4/12/f4132159f1faa93cc13f97b5c68e50b7", O_RDONLY) = 5 read(5, "\327^\34\335\5\264\226\305\326\0\340\27\220n\20P\272\301\2E\340\4\240\202\200\202\200\264t7H\227"..., 1048576) = 1048576 read(5, "\255\27\34\302k\36\360\250w#b\337?\356\347\355\341\24\217&\331\212\374\33\217z\v'(nw\212"..., 1048576) = 843375 lseek(5, 4294918507, SEEK_CUR) = 4296810458 close(5) = 0 stat("/var/lib/backuppc/cpool/54/c2/55c2de84e63acd671a594810eaed936f", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/0e/e0/0fe128c150b7b6166b506369af2bbcbd", 0x7ffe64b62770) = -1 ENOENT (No such file or directory) stat("/var/lib/backuppc/cpool/ea/6c/eb6d1bf9f9cd4e77223eaa01eb66bdd4", {st_mode=S_IFREG|0444, st_size=2696355, ...}) = 0 openat(AT_FDCWD, "/var/lib/backuppc/cpool/ea/6c/eb6d1bf9f9cd4e77223eaa01eb66bdd4", O_RDONLY) = 5 read(5, "\327^\34\335\5\220VG\266\0\340\37\367\340\t\20\10\226\20$H\200@\202\5\33\301\335\t\356\356\356"..., 1048576) = 1048576 read(5, "\34\2129\0027\27@{~\267\203\\\310\226g\270\337F\236\303l\205y\nf!\346I\320\v\372\363"..., 1048576) = 1048576 read(5, "\246\371\367k%Ho\3\361\224\250S\237\334\276\354NG8\214(\267\322C\325P'\250\223A\33F"..., 1048576) = 599203 lseek(5, 4294905847, SEEK_CUR) = 4297602202 close(5) = 0 select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 1 (in [3], left {tv_sec=59, tv_usec=999998}) read(3, "\360_;\247\355\247\355& \n\35oogle.android.apps.cl"..., 21239) = 2565 brk(0x559d8261b000) = 0x559d8261b000 select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 0 (Timeout) write(2, "IOrename: 16 .cid.info.000000.ci"..., 39) = 39 write(2, "IOrename: 22 .layout_version.000"..., 51) = 51 write(2, "IOrename: 11 .rev.000000.rev\n", 29) = 29 write(2, "IOrename: 20 .wifiver.info.00000"..., 47) = 47 write(2, "IOrename: 19 .ash_history.000000"..., 44) = 44 write(2, "IOrename: 15 .cal.bin.000000cal."..., 36) = 36 write(2, "IOrename: 25 .hidden_volume.txt."..., 56) = 56 write(2, "IOrename: 27 .smart_stay_hash.dm"..., 60) = 60 select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 0 (Timeout) select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 0 (Timeout) select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 0 (Timeout) select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 0 (Timeout) select(5, [3], [4], [3], {tv_sec=60, tv_usec=0}) = 0 (Timeout) ... ... ... Any suggestions on how to further troubleshoot this? backu...@kosowsky.org wrote at about 20:55:22 -0500 on Saturday, January 22, 2022: > Need to take this back. > It has nothing to do with the cam_socket. > It gets "stuck" at varying places... as IO slows to a complete halt > (based on iftop) until rsync timesout. > Similarly, 'strace' stalls. > > This happens even if I run rsync_bpc from the command line directly, > but it does *not* happen when I use native rsync with the comparable > options. > > Any ideas on how to debug this further? > > "" wrote at about 15:02:17 -0500 on Friday, January 21, 2022: > > Based on the log file generated by the (equivalent) "naked" rsync > > backup > > > > log: recv cS+++++++++ rwxrwx--- 1006, 1006 0 cam_socket0 > > log: recv cS+++++++++ rwxrwx--- 1006, 1006 0 cam_socket1 > > log: recv >f+++++++++ rwx------ 1000, 1000 8 > hidden_volume.txt > > > > it seems like it gets stuck somewhere between backing up > > 'cam_socket1' and 'hidden_volume.txt' since the last BackupPC log line > > I see is: > > recv cS+++++++++ rwxrwx--- 1006, 1006 0 cam_socket1 > > > > If the problem is backing up a 'socket', the problem is not in native > > rsync as it proceeds fine but rather presumably in rsync_bpc. > > > > > > "" wrote at about 13:41:35 -0500 on Friday, January 21, 2022: > > > I have long been able to back up my (rooted) Android phones using > > > ssh/rsync. > > > I also have no problem backing up my Windows and Linux machines. > > > > > > However, BackupPC timesout when I try to back up an old Samsung S3 > (which > > > used to back up perfectly before). The timeout occurs no matter what > > > value I use even though the total backup size is only about 5.2 GB. > > > > > > The corresponding rsync_bpc client command is: > > > /usr/bin/rsync_bpc --bpc-top-dir /var/lib/backuppc --bpc-host-name > droidtestmachine --bpc-share-name /data --bpc-bkup-num 0 --bpc-bkup-comp 3 > --bpc-bkup-prevnum -1 --bpc-bkup-prevcomp -1 --bpc-bkup-inode0 6621 > --bpc-log-level 1 --bpc-attrib-new -e /usr/bin/ssh -p 22 -l u0_a500 > --rsync-path=PATH=su\ -lpc\ /data/mybin/rsync --super --recursive > --protect-args --numeric-ids --perms --owner --group -D --times --links > --hard-links --delete --delete-excluded --one-file-system --partial > --log-format=log: %o %i %B %8U,%8G %9l %f%L --stats --checksum > --timeout=72000 --exclude=media/0/Download/Temp/* droidy:/data/ / > > > > > > And the corresponding rsync (remote) server command on the android > host is: > > > 20298 10500 0:00 su -lpc /data/mybin/rsync --server --sender > -slHogDtprcxe.iLsfxC > > > 20373 0 0:52 /data/mybin/rsync --server --sender > -slHogDtprcxe.iLsfxC > > > > > > Interestingly, I can successfully manually run the same rsync > > > command directly by invoking rsync with the above parameters and the > > > rsync completes successfully in just a couple of hours (far less than > the > > > timeout). > > > > > > The corresponding rsync client command is: > > > sudo rsync -e /usr/bin/ssh\ -p\ 22\ -l\ u0_a500 --rsync-path=su\ > -lpc\ /data/mybin/rsync --super --recursive --protect-args --numeric-ids > --perms --owner --group -D --times --links --hard-links --delete > --delete-excluded --one-file-system --partial --log-format=log:\ %o\ %i\ %B\ > %8U,%8G\ %9l\ %f%L --stats --checksum --timeout=72000 > --exclude=media/0/Download/Temp/\* droidy:/data/ /tmp/droid-backup > > > > > > And the corresponding rsync server command on the (remote) android > > > host is exactly as above. > > > > > > Since 'manual' rsync works, the problem is presumably *NOT* > > > - The android phone > > > - The setup of ssh and rsync on the phone > > > - The files on the phone > > > - The connection between the phone and the Linux machine invoking > > > rsync or rsync_bpc > > > > > > Also, since my BackupPC server otherwise works fine, there is > > > presumably nothing fundamentally wrong with my BackupPC installation. > > > > > > Finally, since at least some files are transferred (according to the > > > BackupPC logs) before the timeout, there is no problem with the ssh > > > keys for the android connection. > > > > > > > > > So, why would rsync_bpc timeout but not when I run straight rsync? > > > i.e., what is rsync_bpc doing differently that would cause a hang? > > > > > > > > > _______________________________________________ > > > BackupPC-users mailing list > > > BackupPC-users@lists.sourceforge.net > > > List: https://lists.sourceforge.net/lists/listinfo/backuppc-users > > > Wiki: https://github.com/backuppc/backuppc/wiki > > > Project: https://backuppc.github.io/backuppc/ > > > > > > _______________________________________________ > > BackupPC-users mailing list > > BackupPC-users@lists.sourceforge.net > > List: https://lists.sourceforge.net/lists/listinfo/backuppc-users > > Wiki: https://github.com/backuppc/backuppc/wiki > > Project: https://backuppc.github.io/backuppc/ > > > _______________________________________________ > BackupPC-users mailing list > BackupPC-users@lists.sourceforge.net > List: https://lists.sourceforge.net/lists/listinfo/backuppc-users > Wiki: https://github.com/backuppc/backuppc/wiki > Project: https://backuppc.github.io/backuppc/ _______________________________________________ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List: https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki: https://github.com/backuppc/backuppc/wiki Project: https://backuppc.github.io/backuppc/