Backup hanging towards end of backup on Mac

Description

(Still loving UrBackup, it's brilliant!)

While most of the incremental file backups run in a matter of seconds as only a small number of files change between runs, about 25% take 5 minutes and make the computer lock up with spinning 'busy' indicator until the backup completes.

The logs for these backups always show something like this:

{{...
20/03/17 12:39 DEBUG Share "Users" on "XXXX" is still in use (meta-data transfer). Waiting before removing snapshot...
20/03/17 12:40 DEBUG Loading "urbackup/FILE_METADATA|bWvT9K4rfvP1jxeiaLW7|1461". Loaded 49 bytes at 8 Bit/s
20/03/17 12:42 DEBUG Loading "urbackup/FILE_METADATA|bWvT9K4rfvP1jxeiaLW7|1461". Loaded 992 bytes at 64 Bit/s
20/03/17 12:42 INFO Referencing snapshot on "XXXX" for path "etc" failed: FAILED
20/03/17 12:42 INFO Waiting for file hashing and copying threads...}}
...

{{...
20/03/17 12:42 INFO Waiting for file transfers...
20/03/17 12:43 DEBUG Share "Users" on "YYYYY" is still in use (meta-data transfer). Waiting before removing snapshot...
20/03/17 12:43 DEBUG Loading "urbackup/FILE_METADATA|bWvT9K4rfvP1jxeiaLW7|1465". Loaded 41 bytes at 0 Bit/s
20/03/17 12:45 DEBUG Loading "urbackup/FILE_METADATA|bWvT9K4rfvP1jxeiaLW7|1465". Loaded 0 bytes at 0 Bit/s
20/03/17 12:46 DEBUG Loading "urbackup/FILE_METADATA|bWvT9K4rfvP1jxeiaLW7|1465". Loaded 41 bytes at 0 Bit/s
20/03/17 12:47 INFO Referencing snapshot on "YYYYY" for path "etc" failed: FAILED
...}}

As you'll see there's a minute or two between each 'Loading' message.

I've tried digging into the code but as it's multi-threaded it's been too tricky for me to determine exactly what's happening.

Environment

We have a couple of rooms of Mac computers running El Capitan 10.11.6, so about 30 computers. The backups are scheduled in fairly small windows of time such that there are typically 6-10 concurrent backups going on.

There are other Macs being backed up, and I haven't seen this issue with them. (Though I would probably have missed it if it happened occasionally)

Assignee

Martin Raiber

Reporter

Nick Glencross

Labels

None

Components

Affects versions

Priority

Major
Configure