topic EVA snapshot snapclone usage in Disk Enclosures

EVA snapshot snapclone usage

Charles McCary — Fri, 24 Aug 2007 10:32:50 GMT

I guess I'm having trouble visualizing the way these are used. I understand that it's a copy of a given lun in time...but can someone give some real life examples of how they're using these with Oracle DB's.

For example, you make your snapclone...do you make it while the db is running, or do you stop the db, make a snapclone and restart the db?

What are you doing in conjunction with tape backups and snapclones...? Anything?

Do you present your snapclones to hosts and do things with them, if so what?

Sorry for the not so intelligent questions.

c

Re: EVA snapshot snapclone usage

whiteknight — Fri, 24 Aug 2007 12:08:50 GMT

Hi Charles,

Take a look at this documents. This will definitely help you.

Cloning an Oracle/DB2/Sybase Database in a SAN Environment Using EVA Snapclone Technology
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01126538/c01126538.pdf?jumpid=reg_R1002_USEN

WK
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Re: EVA snapshot snapclone usage

A. Clay Stephenson — Fri, 24 Aug 2007 12:22:26 GMT

There are basically two approaches and each have advantages and disadvantages.

1) Shutdown the DB. Snapshot. Restart Database. -- Cold Backup

2) Put Database in Backup Mode. Snapshot. Take Database out of Backup Mode. -- Hot Backup

In both cases, you backup the snapshots. Whenever possible, I actually prefer method 1) because you have all the warm fuzzy safety of a cold backup with almost all of the uptime of a hot backup.

There is also a case where method 2) doesn't help you all that much. Consider the case of application servers and database servers where the application servers store meta-data that describe actual database data. Unless the two are in sync, a hot backup no matter how well it can restore the database will be useless. The only way that really works is to down the applications; down the database; snapshort the applications and database; restart the database; and finally restart the applications. You then can take your cold backups using the snapshots while the users continue to work.