Files with too many hard links can cause rsync to throw a Too many links error, causing backups to fail:
[14 January 2022 10:03:04 AM +0100] [ERROR] rsync: link "/PATH/TO/BACKUPS/jetbackup_1_1_61770148133608258c1020a2/{ACCOUNT}/jbm.account.full/homedir/mail/*/*/.Trash/tmp/903.246.264s0im2o6.4hM436o0tn-1h921s5c4.8u4ffo19.P1.8" => mail/*/*/.Trash/tmp/903.246.264s0im2o6.4hM436o0tn-1h921s5c4.8u4ffo19.P1.8m failed: Too many links (31)
File-list index 0 not in 6541 - 16841 (finish_hard_link) [generator]
rsync error: protocol incompatibility (code 2) at rsync.c(740) [generator=3.1.2]
[14 January 2022 10:03:04 AM +0100] [ERROR] Failed to execute backup typesll /home/{ACCOUNT}/mail/*/*/.Trash/tmp/903.246.264s0im2o6.4hM436o0tn-1h921s5c4.8u4ffo19.P1.8
-rw-r----- 12516 plotsinm4rbella plotsinm4rbella 154945 jul 15 2020 /home/{ACCOUNT}/mail/*/*/.Trash/tmp/903.246.264s0im2o6.4hM436o0tn-1h921s5c4.8u4ffo19.P1.8
On the example above, the particular file has 12516 hard links which are high but typical for files stored on the .Trash/tmp directory. To fix this issue, we recommend excluding the .Trash/tmp folder from your Backup Job by adding it to the appropriate Backup Job Exclude List.
