ODB 1.77 and Time Machine backups

Doug Easterbrook doug at artsman.com
Tue Mar 1 01:57:49 UTC 2022

hi Michael:

to speak to time machine on a DF1 —  it can’t be done.  

in fact, I’d put an exclusion on the folder as follows

tmutil addexclusion /path/to/Folder/ContainingDatafiles

why can’t you?

time machine needs exclusive access to the file get it backed up

If you managed to backup one of the data files (eg DF1 but not DF2), then you have a worthless backup because you must backup all of them at the same time to have data integrity.    You don’t know which segment data is inserted or written, and if your DF1 is auto expanding and need to expand .. the internal DB pointers will be not in a good place.

when we used the ODB, we had a script that would

1) shut down the databridge at an appointed time
2) COPY all files in the folder to another folder
3) start up the data bridge
4) ZIP the COPIED folder into a file like  database_backup_YYMMDD_HHMMSS.zip
5) deleted the files in the copied folder

then let time machine backup the zipped files.

why COPY and then ZIP .. to minimize down time of the database.   copy is much faster, zip is slow, so best to zip a copy and let people into the real database.

if you were using the postgres bridge in studio 10.2, and the database was in postgres, then you can back it up using a pg_dump command while it is being used, so you can have 24x7 access to a database

but even then, you never backup the raw database files —  you always run a dump, and then back that up.     Same with oracle.

the general gist of this is .. no you can’t back up live databases  — you have to use some tool to make a copy that becomes you backup.

and .. all the above is because I’ve been bitten by it.

Doug Easterbrook
Arts Management Systems Ltd.
mailto:doug at artsman.com
Phone (403) 650-1978

> On February 28, 2022, at 5:27 PM, Michael Houlberg <michael at houlbergdevelopment.com> wrote:
> My client asks since ODB is running all the time, can he rely on backups to his .df1, .df2, and other segments as trustworthy?  The thinking is that maybe ODB needs to shut down before a backup can accurately be made?

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