We have nearly 200 GB of data in a production Oracle database broken up into about 100 files of 2 GB. The database incurrs a 5% change per week in the form of new data, no modification nor deletions. I need to copy this data from one mount point to another then bring up the new database on the new mount point in place of the original. The high availability and production nature of this system means that my maintenance windows are few and far between. To minimize my use of the maint window, I would like to pre-copy as much data as I can with RSYNC before the window, then do a final sync of the data during the window with the database down. My question is, will RSYNC be a good option given that the Oracle database is up and running for the initial sync? I'm hoping that RSYNC will be an option for us, as other mirroring strategies I have seen rely upon same size disk devices/partitions, which we do not want because the goal is to put up a single device larger area to keep this data. Please ignore the gaping holes for ideas such as just having Oracle use another mount point in addition to the one it is already using or online VG expansions. David Poe -------------- next part -------------- HTML attachment scrubbed and removed
On Thu, Sep 08, 2005 at 02:20:37PM -0400, Poe, David wrote:> We have nearly 200 GB of data in a production Oracle database broken up > into about 100 files of 2 GB. The database incurrs a 5% change per week > in the form of new data, no modification nor deletions. I need to copy > this data from one mount point to another then bring up the new database > on the new mount point in place of the original. The high availability > and production nature of this system means that my maintenance windows > are few and far between. To minimize my use of the maint window, I > would like to pre-copy as much data as I can with RSYNC before theFor the first copy, it's probably more efficient to just use 'cp', but rsync would work, too.> window, then do a final sync of the data during the window with the > database down. My question is, will RSYNC be a good option given that > the Oracle database is up and running for the initial sync?"good" compared to what? to copying the database files while the database is down? That depends on how much the files changed between the time you copy them and the time you rsync them. Best-case is far better than cp. Worst-case is not much worse than cp. -chris> I'm hoping > that RSYNC will be an option for us, as other mirroring strategies I > have seen rely upon same size disk devices/partitions, which we do not > want because the goal is to put up a single device larger area to keep > this data. Please ignore the gaping holes for ideas such as just having > Oracle use another mount point in addition to the one it is already > using or online VG expansions. > > David Poe> -- > To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync > Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
MessageMuch smaller and MySQL rather than Oracle. Essentially without a "window", but done when things are supposedly relatively quiet. Two rsync's back to back. The first one takes most all of the time. The second one is fast enough that I don't bother to rebuild indexes if I pull a copy during heavy use. Guessing from limited knowledge and some experience. Large files with some new stuff at the end can take a while to find the right places to add stuff. Start the initial rsync early, very early. Expect surprises in how slow the first rsync is and how fast the second rsync is. Assuming that Oracle is any good at recovering from power failures, odds are that most everything that matters IS on disk, at least the bulk of it. (That's a guess from someone who does NOT know what he's talking about) -----Original Message----- From: rsync-bounces+tony=servacorp.com@lists.samba.org [mailto:rsync-bounces+tony=servacorp.com@lists.samba.org]On Behalf Of Poe, David Sent: Thursday, September 08, 2005 1:21 PM To: rsync@lists.samba.org Subject: Open Database RSYNC We have nearly 200 GB of data in a production Oracle database broken up into about 100 files of 2 GB. The database incurrs a 5% change per week in the form of new data, no modification nor deletions. I need to copy this data from one mount point to another then bring up the new database on the new mount point in place of the original. The high availability and production nature of this system means that my maintenance windows are few and far between. To minimize my use of the maint window, I would like to pre-copy as much data as I can with RSYNC before the window, then do a final sync of the data during the window with the database down. My question is, will RSYNC be a good option given that the Oracle database is up and running for the initial sync? I'm hoping that RSYNC will be an option for us, as other mirroring strategies I have seen rely upon same size disk devices/partitions, which we do not want because the goal is to put up a single device larger area to keep this data. Please ignore the gaping holes for ideas such as just having Oracle use another mount point in addition to the one it is already using or online VG expansions. David Poe -------------- next part -------------- HTML attachment scrubbed and removed
Poe, David wrote:> We have nearly 200 GB of data in a production Oracle database broken up > into about 100 files of 2 GB. The database incurrs a 5% change per week > in the form of new data, no modification nor deletions. I need to copy > this data from one mount point to another then bring up the new database > on the new mount point in place of the original. The high availability > and production nature of this system means that my maintenance windows > are few and far between. To minimize my use of the maint window, I > would like to pre-copy as much data as I can with RSYNC before the > window, then do a final sync of the data during the window with the > database down. My question is, will RSYNC be a good option given that > the Oracle database is up and running for the initial sync?I would suggest you do some experimentation. Remember that rsync will have to read both the source and destination files in their entirety in addition to doing any writes that are necessary. When source and destination are both on the local machine, you may be worse off than just doing a copy. Try using --inplace on the final rsync. The procedure I wrote specified individual files and I think because of that, I had to explicitly use --no-whole-file. Don't use -S with --inplace or you will get corruption. Also, you might try forcing a checkpoint just prior to your initial copy. You can avoid updates to a tablespace by putting it into hot backup mode. Linus