rsync read block size

[Ming Zhang]

On Sat, May 23, 2009 at 10:25 AM, Matthias Schniedermeyer <ms at citd.de> 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?



>
>> > 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.
>
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> Bis denn
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