topic Re: Quick Question Re. set file/nobackup in Operating System - OpenVMS

Quick Question Re. set file/nobackup

The Brit — Tue, 25 Jan 2011 16:48:24 GMT

If I set a directory file /NoBackup, will that exclude directory contents and all sub-directories?

Dave.

Re: Quick Question Re. set file/nobackup

The Brit — Tue, 25 Jan 2011 16:53:42 GMT

Forget it. Quick test shows that it doesnt.

Dave.

Re: Quick Question Re. set file/nobackup

Hoff — Tue, 25 Jan 2011 17:04:41 GMT

Per classic keep-it-simple and irrespective of this posting that [identity of guilty party expurgated] wrote a decade ago:

http://h71000.www7.hp.com/wizard/wiz_3612.html

I wouldn't personally particularly trust this BACKUP behavior to be reliable in either possibility. Dependencies on undocumented or obscure or corner cases within BACKUP can be somewhat fickle over time.

I'd (still) use the /EXCLUDE as was mentioned, and I'd also periodically verify the contents of the media and the recovery of the data.

Re: Quick Question Re. set file/nobackup

Steven Schweda — Tue, 25 Jan 2011 17:26:58 GMT

No, but a feature like that could be handy
for, say, Web browser caches and the like.
No doubt the VMS engineers will hop right
onto that.

Re: Quick Question Re. set file/nobackup

The Brit — Tue, 25 Jan 2011 17:28:13 GMT

Main reason for asking is that /Image ignores /Exclude, but not /NoBackup. So particularly useless files could be marked /NoBackup and their data would not clutter up an image backup of the disk.

for example, I often have to restore data files from specific backups so that some retroactive data mining and report generation can be done. These datasets are usually large, and it is often difficult find out if, or when they have outlived their usefulness. Marking them as no backup avoids allows Image backups to be done without dumping this data, night after night, onto the daily backup tapes.

Dave.

Re: Quick Question Re. set file/nobackup

Hoff — Tue, 25 Jan 2011 18:22:13 GMT

Disks are tertiary storage. Tapes are quaternary at best, and can be relegated to quinary storage in some designs.

There's the question of whether tape media is appropriate, given the street price of disk. You don't need speed here, so big, dumb, low-RPM, capacious and cheap(er) disks can work, and less-expensive DAS storage, can be an entirely reasonable choice for this sort of usage.

Options? HP MDS600 or third-party RAID arrays, for instance. Here are some of the HP options for the BladeSystem gear:

http://h18006.www1.hp.com/storage/bladesystem/index.html

There's the OpenVMS system management question of whether a regular full-disk /IMAGE is appropriate for this case. That's good for system disks, but is not necessarily the most appropriate choice for other sorts of archives.

As for dumping the data into BACKUP archives unnecessarily (and whether the archives are on disk or tape), that case can often be managed with BACKUP incremental operations, where you only pick off the files that have been modified, between periodic full backups (where you pick off everything).

ps: what is current-generation primary and secondary storage? memory and memory caches and memory disks, and SSD. And disks are increasingly becoming the near-line removable storage device of choice, too; they're displacing tapes for even some near-line archival use.

Re: Quick Question Re. set file/nobackup

John Gillings — Wed, 26 Jan 2011 20:26:54 GMT

>this posting that [identity of guilty party
>expurgated] wrote a decade ago:

Almost all wizard postings are indelibly marked with the fingerprint of the author ;-)

(of course, they're probably only recognisable by the actual wizards)