MartyConnelly
martyconnelly at shaw.ca
Sat Feb 22 11:49:48 CST 2003
I have used double mirroring with an Oracle database that was 24/7. You break one mirror to do a hot backup of the database. The broken mirror is then copied to tape. See the Oracle Backup & Recovery Handbook. Wortz, Charles wrote: > John, > > This is not an area where I claim any expertise. What I know is every > transaction written to the main db is also supposed to be written to > its mirror. How they resync them after one goes down is not something > I have had to worry about. There may be others on this list that can > speak to that. > > > Charles Wortz > Software Development Division > Texas Education Agency > 1701 N. Congress Ave > Austin, TX 78701-1494 > 512-463-9493 > CWortz at tea.state.tx.us > (SELECT * FROM users WHERE clue > 0) > > -----Original Message----- > From: John W. Colby [mailto:jcolby at colbyconsulting.com] > Sent: Friday 2003 Feb 21 14:07 > To: dba-sqlserver at databaseadvisors.com > Subject: RE: [dba-SQLServer]Rolling back a transaction log? > > Charles, > >>But the mirror gives a real-time backup which may solve half of > Francisco's problem. > > Yea, but these (mirrors) are for situations where a disk dies etc. If > you intentionally delete something, the mirror is supposed to > immediately write that delete to the mirrored drive as well (isn't it?). > > > John W. Colby > Colby Consulting > www.ColbyConsulting.com > > -----Original Message----- > From: dba-sqlserver-admin at databaseadvisors.com > [mailto:dba-sqlserver-admin at databaseadvisors.com]On Behalf Of > Wortz, Charles > Sent: Friday, February 21, 2003 3:00 PM > To: dba-sqlserver at databaseadvisors.com > Subject: RE: [dba-SQLServer]Rolling back a transaction log? > > John, > > There is not much you can do if you have a DBA that intentionally > deletes both copies of a file. But the mirror gives a real-time > backup which may solve half of Francisco's problem. The other > half will have to be taken care of by the DBA's boss. Unless you > only have one server, even a bloody idiot knows better than to > have both development and production on the same server. > > Charles Wortz > > -----Original Message----- > From: dba-sqlserver-admin at databaseadvisors.com > [mailto:dba-sqlserver-admin at databaseadvisors.com] On Behalf Of > John W. Colby > > Sent: Friday 2003 Feb 21 13:47 > To: dba-sqlserver at databaseadvisors.com > Subject: RE: [dba-SQLServer]Rolling back a transaction log? > > Would mirroring really help if someone intentionally deletes it? > Wouldn't the mirror be deleted as well? > > John W. Colby > Colby Consulting > www.ColbyConsulting.com <file://www.ColbyConsulting.com> > > -----Original Message----- > From: dba-sqlserver-admin at databaseadvisors.com > [mailto:dba-sqlserver-admin at databaseadvisors.com]On > <mailto:dba-sqlserver-admin at databaseadvisors.com%5DOn> Behalf Of > Wortz, > Charles > Sent: Friday, February 21, 2003 2:34 PM > To: dba-sqlserver at databaseadvisors.com; sswug-sql2k at topica.com > Subject: RE: [dba-SQLServer]Rolling back a transaction log? > > > Francisco, > > How frequently you backup is dependent on how valuable is the lost > data. > If you can afford to lose a day's worth of data, or if you can easily > recreate the day's worth of data, then you backup daily. If you can > afford to lose an hour's worth of data, or if you can easily recreate > the hour's worth of data, then you backup hourly. If you cannot > afford > to lose any data, then you mirror your database. > > Charles Wortz > > > -----Original Message----- > From: Francisco H Tapia [mailto:my.lists at verizon.net] > Sent: Friday 2003 Feb 21 13:19 > To: dba-SQLServer at databaseadvisors.com; sswug-sql2k at topica.com > Subject: [dba-SQLServer]Rolling back a transaction log? > > > Well it finally happened... We have a Complaint database that runs in > conjunction with a goldmine database. The Goldmine database tracks > outgoing calls made by our company to customers in order to track > sales > leads and now complaints. Since 4/1/2002 we have not had a database > error or hiccup until now. The company's official DBA, while > working on > a development database on the production server (yes, that's right) > inadvertently wiped out my database instead of his test one this > morning, The users of the Complaint db suddenly began to complaining > that there were no records, and upon checking I found this to be the > case. I backup every night, and I have the log file backup when it > reaches 60%. BUT. I did not have *ANY* protection for the moments > before the wipe out. Initially I panicked about not being able to > kick > the users out quickly enough... I didn't bother to *remember* that > I had > a Kill All Users In Db script. So about 10 minutes later (after > kicking > all the users out) I restored the database back to last log > backup, but > that was not good as it had the transactions that wiped out the > database. SO I had to restore to last nights copy officially killing > all entries from 10am and prior. :( > > I've secured my script for killing Active Users in the DB. And My > boss > knows *who* wiped out the database, in fact I made sure he knew as > soon > as it happened ... maybe that's not a good political move, but I'm in > charge of the db. Now the question is... Since the log file is only > 1meg long and on average it doesn't backup the log for perhaps > every 2 > to 3 days... (I do make a full backup every night). I suppose I > could > manage the backups to include incremental changes every hr, so > that as > little data is lost? What do you guys suggest? > > > -Francisco > http://rcm.netfirms.com >