[Info-vax] backups and compaction or nocompaction might be better

[Bob Gezelter]

On Tuesday, January 29, 2013 11:23:26 AM UTC-5, pcov... at gmail.com wrote:
> On Tuesday, January 29, 2013 10:47:14 AM UTC-5, Stephen Hoffman wrote:
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> > On 2013-01-29 15:28:54 +0000, pcoviello at gmail.com said:
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> > > that was what I was afraid of and unfortunately I can not un-encrypt 
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> > > the databases :-(
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> > Copying a live database is likely futile, in any case.  Databases 
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> > aren't fond of that, given there's no coordination with BACKUP.  
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> > Copying an encypted database created by the database-specific 
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> > (lowercase-backup) backup tool is usually entirely feasible, but that 
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> > archiving processing is probably best performed with just a generic 
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> > BACKUP command and without resorting to compression or compaction or 
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> > encryption.
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> > If the operation is a file-based BACKUP and you're intending to archive 
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> > the whole disk and particularly the application-related and ancillary 
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> > files, I'd be seriously tempted to omit the database files and related 
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> > baggage from that BACKUP, and storing that stuff in a different saveset 
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> > on the tape, or on a different tape.
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> > -- 
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> > Pure Personal Opinion | HoffmanLabs LLC
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> ok first what is endless september?
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> as far as databases we do a freeze of the application and while the dbs are acquiesced we do a copy to a clone and backup the whole cloned disk.  so we get all files including the cache.dat files.

Paul,

A "freeze" of the application is likely not enough. The database must be completely inactive to get a valid copy.

As Hoff noted, one possibility is excluding the database-related items from the BACKUP, and using the database's own tools to produce a presumably consistent backup of the database.

If a full BACKUP image is needed, one can use volume shadowing to your advantage to minimize downtime: add a member to the shadow set, wait for the copy to be fully synchronized, quiesce the database, disconnect the EXTRA member, release the database back into production. 

The removed shadow set member is a current copy of the (momentarily idled) database. It can then be mounted privately and a BACKUP/IMAGE can be done. 

- Bob Gezelter, http://www.rlgsc.com