[Bacula-users] Job scheduling not behaving as expected

I've been playing with bacula and have noticed something that doesn't 
quite look right to me.  I'm spooling backups to disk before writing 
them to tape.  I've set it up to accept up to 8 jobs at the same time. 
When it first starts out it will spool all 8 at the same time.  However 
as it progresses and gets near the end of the list of jobs it seems that 
something is blocking some of the spools.  Here is the output of "status 
storage" near the end of the run.  I can see one despooling and only one 
spooling.  There are three that are just sitting there doing nothing. 
The clients are idle and the backup server has plenty of cpu/memory/disk 
throuput available to it.


Running Jobs:
Writing: Full Backup job bugs.contribs.local JobId=12 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=0 despooling=1 despool_wait=0
     Files=39,911 Bytes=745,268,014 Bytes/sec=1,184,845
     FDReadSeqNo=308,406 in_msg=208109 out_msg=9 fd=14
Writing: Full Backup job mythtv64.lordsfam.net JobId=13 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=1 despooling=0 despool_wait=0
     Files=1,222 Bytes=105,669,873 Bytes/sec=8,805,822
     FDReadSeqNo=9,756 in_msg=6993 out_msg=5 fd=27
Writing: Full Backup job xen32-4.contribs.local JobId=14 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=0 despooling=0 despool_wait=0
     Files=0 Bytes=0 Bytes/sec=0
     FDReadSeqNo=6 in_msg=6 out_msg=4 fd=20
Writing: Full Backup job xen32-3.contribs.local JobId=15 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=0 despooling=0 despool_wait=0
     Files=0 Bytes=0 Bytes/sec=0
     FDReadSeqNo=6 in_msg=6 out_msg=4 fd=24
Writing: Full Backup job xen32-2.contribs.local JobId=16 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=1 despooling=0 despool_wait=0
     Files=6,662 Bytes=91,902,974 Bytes/sec=7,658,581
     FDReadSeqNo=56,971 in_msg=38232 out_msg=5 fd=13


As soon as the despooling job finishes then the other three start spooling:

Running Jobs:
Writing: Full Backup job mythtv64.lordsfam.net JobId=13 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=1 despooling=0 despool_wait=0
     Files=5,398 Bytes=365,347,751 Bytes/sec=7,306,955
     FDReadSeqNo=45,911 in_msg=32059 out_msg=5 fd=27
Writing: Full Backup job xen32-4.contribs.local JobId=14 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=1 despooling=0 despool_wait=0
     Files=2,137 Bytes=79,500,544 Bytes/sec=8,833,393
     FDReadSeqNo=18,061 in_msg=12302 out_msg=5 fd=20
Writing: Full Backup job xen32-3.contribs.local JobId=15 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=1 despooling=0 despool_wait=0
     Files=4,293 Bytes=127,422,442 Bytes/sec=14,158,049
     FDReadSeqNo=32,905 in_msg=22365 out_msg=5 fd=24
Writing: Full Backup job xen32-2.contribs.local JobId=16 Volume="MA3001"
     pool="Monthly" device="SSL2020-AIT3-Drive1" (/dev/nst0)
     spooling=1 despooling=0 despool_wait=0
     Files=31,778 Bytes=370,412,411 Bytes/sec=7,408,248
     FDReadSeqNo=259,814 in_msg=174299 out_msg=5 fd=13


The effect of this is that I'm not able to keep the tape running at full 
speed.  What ends up happening is that it will spool the first set of 
jobs and then start writing them to tape.  After it has finished writing 
a job to tape it will sometimes start spooling a waiting job.  Most of 
the times it won't until all the spooled jobs are despooled.  I've set 
aside plenty of spool space and it doesn't even come close to filling it up.

I'd appreciate it if anyone could point me in a direction that might 
indicate what I've missed or done wrong.  I'd really like to be able to 
stream to the tape drive as fast as I possibly can.

Thanks,

-Shad

-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Bacula-users mailing list
Bacula-users AT lists.sourceforge DOT net
https://lists.sourceforge.net/lists/listinfo/bacula-users