The issue isn't whether it's destructive, it's whether it's recoverable. Ed Crowley MCSE+Internet MVP Freelance E-Mail Philosopher Protecting the world from PSTs and Bricked Backups!T
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matthew Joyce Sent: Thursday, June 24, 2004 11:07 PM To: Exchange Discussions Subject: RE: Shadow Copying of Exchange 2003 An interesting post to what was a deteriorating thread. I'm interested to know what size store you had in mind for your scenario. If I only have a small store, copies will be fast and drive space is cheap, does this make it an attractive solution for small installations ? thanks Matt Joyce Children's Cancer Institute Australia http://www.ccia.org.au > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Webb, Andy > Sent: Friday, 25 June 2004 11:32 AM > To: Exchange Discussions > Subject: RE: Shadow Copying of Exchange 2003 > > > One of many other differences with Exchange and SQL is that because of > the structure of the files, much larger portions of the data may > change between snapshots. > > So, you snap at 9pm, then do a backup, which zeros out deleted pages, > then maintenance runs to clean out tombstoned indexes, coallesce pages > and about 8 other things, then you snap again at 9am. > > At 10am your store crashes and so you pull back the 9am snapshot - > it's pretty quick, but still not instant because between 9am and 10am > 80% of your users were online regenerating new indexes and making > changes to all the items they received overnight. But all and all you > have somewhere south of 5% of the blocks to copy from the snapshot > back onto the production database LUNs. But wait - it's not really > wise to lose your "latest state", so somehow before you snap back to > 9am, you should get a backup of the store at the time of the crash. > This isn't a snapshot at this point. > > But let's assume you have a way to handle that responsible backup. > You snap back to 9am and discover that that store is corrupt too. > Bummer. Now you have to snap back to 9pm and somewhere north of 40% of > your database pages have changed. > Bummer again, that's going to take actual time to copy that much data. > So, now it's 3pm or so and you're finishing up the copy and you have > to get the store started and replay any logs you have so you don't > lose all that data from the 9pm-10am timeframe. That might be a lot > of logs, so again, not instant. > > Every one of these challenges can be addressed with money and > hardware. > > For some people, the cost of having the mail system down is > commensurate with those costs. For others it's not; a more > traditional tape based system or "online backup" scenario is more > practical. > > Regardless, this illustrates that snapshot backups are an iceberg and > the VSS capability in the OS is merely the tip. > > There were some good presentations at TechEd on this and there are a > couple new whitepapers out on the Exchange Site. > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Henry Sieff > Sent: Thursday, June 24, 2004 5:00 PM > To: Exchange Discussions > Subject: RE: Shadow Copying of Exchange 2003 > > Volume shadow copy is like the various volume copying products used > for years now on high end SAN's (like HDS truecopy/shadowcopy). > Basically, you have two equal sized volumes (PRODUCTION and BACKUP). > These are kept in sync by the SAN controller. At any time, you can > break the sync, and then BACKUP is a valid backup of PRODUCTION. You > can mount BACKUP on another server (or the same one if you're not > running MSCS) and use the file on it or whatever. > > All the syncing is block level, and even if you've had it unsynced for > a while, its pretty quick to catch up once you unmount and resync. > > Hence the issue (up until now?) with exchange/SQL. While exchange (or > SQL) > is running, the files themselves are inconsistant, so what you had to > do was stop exchange/SQL, then break the pair, then you restart > exchange SQL. Then you could make a tape copy of the BACKUP volume at > your leisure, or not. > > What Volume Shadow Services is supposed to do is handle all of that by > making the files consistant and then syncing then breaking, in effect > giving you an instantaneous backup. > > Henry > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] > Behalf Of Ajay > > Kulsh > > Sent: Thursday, June 24, 2004 2:32 PM > > To: Exchange Discussions > > Subject: Re: Shadow Copying of Exchange 2003 > > > > > > Ken, > > > > I get the error message "Sorry this meeting has already finished". > > -- > > > > And, about one of my original questions, how can the huge exchange > > database of many GBs be copied in "about a minute" and where it is > written to? > > > > So far, only Samantha's response makes sense unless one of you have > > actually used this feature and can give some inside info. > > > > Jay > > > > ----- Original Message ----- > > From: Ken Cornetet > > To: Exchange Discussions > > Sent: Thursday, June 24, 2004 8:31 AM > > Subject: RE: Shadow Copying of Exchange 2003 > > > > > > You all may want to view this webcast: > > > > Go to: http://www.placeware.com/cc/mseventsbmo/join > > Your Name: (enter your name) > > Meeting ID: 1032251381 > > Meeting Password: webcast > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of > > Bridges, Samantha > > Sent: Thursday, June 24, 2004 9:57 AM > > To: Exchange Discussions > > Subject: RE: Shadow Copying of Exchange 2003 > > > > > > I understand that you cannot or should not think of Shadow > copying the > > Exchange IS. The shadow copying feature in Windows 2003 is > for the OS > > not for a database. To be clearer, you can use shadow copy for > > Windows or the OS not for the Exchange database. > > > > Hope this makes sense. We were in the same thought pattern > as you and > > learned this wasn't going to work. > > > > Samantha > > > > -----Original Message----- > > From: Ajay Kulsh [mailto:[EMAIL PROTECTED] > > Sent: Wednesday, June 23, 2004 8:42 PM > > To: Exchange Discussions > > Subject: Shadow Copying of Exchange 2003 > > > > > > I need some enlightenment regarding Shadow Copying of Exchange 2003. > > > > I have read MS article - 822896 and some other references to > > understand shadow copying. What is not clear to me that if it takes > > typically only *about a minute* to create a shadow copy, how long > > does it normally take to write this data to a backup hardware? And > > while backup program is writing this, where is data kept? Memory > > cannot keep so much and I don't see any hard drive space > > requirements mentioned. > > > > Can shadow copying of Exchange 2003 only work with backup like SAN, > > not normal tape drive? > > > > Jay Kulsh > > > > > > _________________________________________________________________ > > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > > Web Interface: > > http://intm-dl.sparklist.com/cgi-bin/lyris.pl?enter=exchange&t > > ext_mode=& > > lang=english > > To unsubscribe send a blank email to %%email.unsub%% > > Exchange List admin: [EMAIL PROTECTED] > > To unsubscribe via postal mail, please contact us at: > > Jupitermedia Corp. > > Attn: Discussion List Management > > 475 Park Avenue South > > New York, NY 10016 > > > > Please include the email address which you have been contacted with. > > > > --- > > [This E-mail scanned for viruses by Declude Virus] > > > > --- > > [This E-mail scanned for viruses by Declude Virus] > > > > > > _________________________________________________________________ > > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > > Web Interface: > > http://intm-dl.sparklist.com/cgi-bin/lyris.pl?enter=exchange&t > ext_mode=& > lang=english > To unsubscribe send a blank email to > %%email.unsub%% > Exchange List admin: [EMAIL PROTECTED] > To unsubscribe via postal mail, please contact us at: > Jupitermedia Corp. > Attn: Discussion List Management > 475 Park Avenue South > New York, NY 10016 > > Please include the email address which you have been contacted with. > > > > _________________________________________________________________ > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > Web Interface: > http://intm-dl.sparklist.com/cgi-bin/lyris.pl?enter=exchange&t > ext_mode=& > lang > =english > To unsubscribe send a blank email to > %%email.unsub%% > Exchange List admin: [EMAIL PROTECTED] > To unsubscribe via postal mail, please contact us at: > Jupitermedia Corp. > Attn: Discussion List Management > 475 Park Avenue South > New York, NY 10016 > > Please include the email address which you have been contacted with. > > > _________________________________________________________________ > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > Web Interface: > http://intm-dl.sparklist.com/cgi-bin/lyris.pl?enter=exchange&t ext_mode=& lang =english To unsubscribe send a blank email to %%email.unsub%% Exchange List admin: [EMAIL PROTECTED] To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. 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