Question about Backup

Hello to all In our Production we make a full backup of the instance (300 Go) Weekly and L1 (the size depends) daily, and we still waiting till the backups ends to launch the batchs it takes 45 minutes for L0 and about 1 hour and 30 minutes for L1 My Question : Should we wait the end of backup (ontape) to launch the batchs or can we lauch the batches just after launching the informix backups ? so we can save about 1 hour. Thanks in advance

In order to answer that question, you should understand the implications: - The engine activity does not affect the "result" of the backup. A restore of the backup (without logs) will always provide the state of the database when the backup started (naturally all non closed transactions will be rolled back) - But to give you backup consistency, the images of the pages saved to tape/disk/storage manager must be the image of the pages when the backup started. And the engine must implement a mechanism to give you that even while the pages are being changed. This is done by copying the initial image of the page to the temporary spaces whenever a page saved is first changed after bakup start. These before images, created in the temp spaces are appended to the end of each dbspace image sent to tape With this in mind, and it may seem a bit confusing, if your pages change a lot, or better saying, if a lot of pages change after the backup start, the overload and backup image size will increase. Situations have happened where customers didn't have enough temp space and it caused the backup to abort. So... how much changes your batches do? Imagine an ideal situation where the batches only do reporting... apart from overloading the I/O I would say that you would not encounter any more issues... But if your batches change a lot of pages.... maybe it's better to wait... Keep in mind that a page will be saved only once (the first time it's changed). So if a batch keeps updating a very restricted set of data it would probably not cause a big issue... Hope this helps... sorry, but there is no yes/no answer for this. Regards On Fri, Feb 7, 2014 at 6:47 PM, SMITH JOHN <daylight@webmails.com> wrote: > Hello to all > > In our Production we make a full backup of the instance (300 Go) Weekly > and L1 > (the size depends) daily, and we still waiting till the backups ends to > launch > the batchs > > it takes 45 minutes for L0 and about 1 hour and 30 minutes for L1 > > My Question : Should we wait the end of backup (ontape) to launch the > batchs > or can we lauch the batches just after launching the informix backups ? so > we > can save about 1 hour. > > Thanks in advance > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently... --047d7b33d05082637804f1d5a414

Thanks a lot :) I Understand and i think also that it is better to wait till the backup ends.

You can begin your batch processing immediately after the archive, however, like the dropped database in the logs, you should not be relying on the archive to save the state of the database from before the batch processing began. Archives are for restoring the server the its latest state after a hard crash of the machine and/or disks, not for saving a particular state. The proper tool for making a state backup would be dbexport & dbimport (or my dbexport replacement tool, myexport & myimport). You COULD use the archive. You would have to switch logical logs (onmode -l) just before starting the batch processing, then if you need to restore the state to before the batch processing started, you would restore the engine with the archive then restore any logical logs completed after the archive started up to the one that was current when you switched logs. Then, once that log has been restored, you will bring the engine online with onmode -m without restoring any later logical log files. That would be the procedure, but it is not "best practice". Art Art S. Kagel, Principal Consultant ASK Database Management Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Fri, Feb 7, 2014 at 1:47 PM, SMITH JOHN <daylight@webmails.com> wrote: > Hello to all > > In our Production we make a full backup of the instance (300 Go) Weekly > and L1 > (the size depends) daily, and we still waiting till the backups ends to > launch > the batchs > > it takes 45 minutes for L0 and about 1 hour and 30 minutes for L1 > > My Question : Should we wait the end of backup (ontape) to launch the > batchs > or can we lauch the batches just after launching the informix backups ? so > we > can save about 1 hour. > > Thanks in advance > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --001a1137f67ccfb85704f1edddae

Not the Best practice but it works i guess ? :) thank you Mr art, i keep your explanation in mind ;) in case i need it