Re: BackupPC_refCountUpdate: ERROR pool file ... has digest ... instead of ...

Hi there,

Long day today, sorry.

On Thu, 23 Jul 2026, Ronald Colcernian wrote:

> I have 1/2 dozen of these errors in the main BackupPC Log file.
>
> Run: I found the following recommendations:
>
> BackupPC_refCountUpdate -m -f -c
>
> *Questions:*
> 1) Is this the proper tool to address this type of error?

Not necessarily.  I'd want to know *why* this has happened.  This tool
won't tell you that.  When the problem is fixed, I'd want to know that
it has stopped happening.  It's a good tool for that.

The errors are presumably generated and logged by the nightly checks.
If you have $Conf{PoolNightlyDigestCheckPercent} at the default 1% per
nightly run, each nightly run checks a random 1% of the pool files.
If that's the case and you have half a dozen of the errors it could be
that there are a lot more waiting to be discovered.  I'd be more than
a little uncomfortable with that.  Have you done checks on the storage
medium/filesystem(s)?  I'd be wondering about their reliability.  On
the systems here I'm almost sure I've never seen this error message.
I grepped the last seven years of logs on my busiest backup machine
and found none.

> if not what would be the better tool?

You could change the 1% setting (if it is still at the default) to
check files more quickly, or try the tool posted in the Wiki here:

https://github.com/guille2306/backuppc_check_pool

it will check all the pool if you want to.  (Strictly speaking the cpool.)

> 2) How long will it take using the tool?
> I understand this is a function of the speed of the machine and disk
> subsystem.

Hmmmm... perhaps more to the point it will depend on how many pool
files there are and how large they are.  Very difficult to say, but
you can at least get an idea using the 'progress' option.  Probably
with a 3TByte pool it won't be like greased lightning on *anything*.
You can stop a test at any time with CTRL-C, it won't break things.
That means you can try a test with one set of options and, if looks
like it's going to take too long for you stop it and try again with
different options.

> I prefer that BackupPC is not shutdown for days.

:)

I'd probably try doing a chunk of checks each day, adjusting 'chunk'
to suit the hardware performance and your waking hours. :/

> Can the tool be run by host?

Yes.  If you run it without any options it prints a help page:

8<--------------------------------------------------------------------------

$ /usr/local/BackupPC/bin/BackupPC_refCountUpdate
Usage:
   BackupPC_refCountUpdate -h HOST [-c] [-f] [-F] [-o N] [-p] [-v]
       With no other args, updates count db on backups with poolCntDelta files
       and computes the host's total reference counts.  Also builds refCnt for
       any >=4.0 backups without refCnts.
         -f     - do an fsck on this HOST, which involves a rebuild of the
                  last two backup refCnts.  poolCntDelta files are ignored.
                  Also forces fsck if requested by needFsck flag files
                  in TopDir/pc/HOST/refCnt.  Equivalent to -o 2.
         -F     - rebuild all the >=4.0 per-backup refCnt files for this
                  host.  Equivalent to -o 3.
         -c     - compare current count db to new db before replacing
         -o N   - override $Conf{RefCntFsck}.
         -p     - don't show progress
         -v     - verbose
     Notes: in case there are legacy (ie: <=4.0.0alpha3) unapplied poolCntDelta
     files in TopDir/pc/HOST/refCnt then the -f flag is turned on.

   BackupPC_refCountUpdate -m [-f] [-p] [-c] [-r N-M] [-s] [-v] [-P phase]
         -m       Updates main count db, based on each HOST
         -f     - do an fsck on all the hosts, ignoring poolCntDelta files,
                  and replacing each host's count db.  Will wait for backups
                  to finish if any are running.
         -F     - rebuild all the >=4.0 per-backup refCnt files.
         -p     - don't show progress
         -c     - clean pool files
         -r N-M - process a subset of the main count db, 0 <= N <= M <= 255
         -s     - prints stats
         -v     - verbose
         -P phase Phase from 0..15 each time we run BackupPC_nightly.  Used
                  to compute exact pool size for portions of the pool based
                  on the phase and $Conf{PoolSizeNightlyUpdatePeriod}.

8<--------------------------------------------------------------------------

HTH

-- 

73,
Ged.


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