On 23.05.2009 17:32, Ming Zhang wrote: > On Sat, May 23, 2009 at 10:25 AM, Matthias Schniedermeyer <[email protected]> > wrote: > > On 23.05.2009 08:44, Ming Zhang wrote: > >> > > >> > No. The block size is NEVER relevant for a copy via rsync, bits are bits > >> > regardless of you copying them bit by bit or in larger groups. > >> > > >> > >> please have a read > >> http://www.oracle.com/technology/documentation/berkeley-db/db/ref/transapp/archival.html > >> see the db page size issue when copy a online db. > > > > The meantioned utility to create the copy is NOT rsync, it's hotbackup. > > > > After the hotbackup is done, you can do whatever you like with the > > created copy. In your case you want to transfer it to another computer. > > that is what i meant. > > i have DB that in hundreds of GBs. copy it out first by db_hotbackup > take time and space. why not combine db_hotbackup and rsync to do 1 > step work?
I have to fold. I don't seen any imediate possibility to combine hotbackup & rsync. On the other hand the quiescent and device/filesystem snapshotting results in a rsyncable copy. On first glance db_checkpoint appears to provide the quiescent part by doing checkpoints. Other than that, if you know how the database is structured you could write a script/program to syncronize the database content on a higher level than bit-copying the backing-store. > >> > The man-page of db_hotbackup meantions (indirectly) that the backup is > >> > without cooperation from the application and the database content may be > >> > inconsistent. Not from the technical standpoint of BDB, but from the > >> > high-level application standpoint. The application has to use > >> > transactions correctly so that the database-content is consistent at any > >> > point in time. > >> > > >> > In short: If your application does correcy transactions, hotbackup > >> > appears to be a useable variant of the "snapshot"-db-backup type. > >> > > >> > >> please not only read the man page of db_hotbackup, but also read the > >> source code and the related BDB reference guide. then u will know that > >> db_hotbackup do some db related work and then begin to copy file use > >> posix read/write. and it read at multiple DB size. > > > > -- > > > > > > > > > > Bis denn > > > > -- > > Real Programmers consider "what you see is what you get" to be just as > > bad a concept in Text Editors as it is in women. No, the Real Programmer > > wants a "you asked for it, you got it" text editor -- complicated, > > cryptic, powerful, unforgiving, dangerous. > > > > -- Bis denn -- Real Programmers consider "what you see is what you get" to be just as bad a concept in Text Editors as it is in women. No, the Real Programmer wants a "you asked for it, you got it" text editor -- complicated, cryptic, powerful, unforgiving, dangerous. -- Please use reply-all for most replies to avoid omitting the mailing list. To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
