[DRBD-user] Preventing initial full sync on new install

Florian Haas florian.haas at linbit.com
Mon Nov 26 17:01:14 CET 2007

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

On Monday 26 November 2007 16:28:17 Blechman, Ronald I, Jr (Ron) wrote:
> "this" = whether one can actually write to the disk while
> synchronization is in process.
> Perhaps the confusion is with the word "usable"..... does "usable" mean
> "read and write" or just "read"?
> My assumption was with at least protocol C that the system is blocking
> until the writes / synchronization has completed.

That assumption is incorrect. You can read from and write to the device 
immediately. Block-by-block replication on the one hand and background sync 
on the other will run in parallel.

You can even switch roles and make a not-yet-synced device Primary, in which 
case it will fetch as-yet-unsynced blocks over the wire, from the node that 
has a complete set of good data, and read already-synced blocks locally. As 
long as a network connection between the two is available, that is.

And this is not dependent on the protocol you use.


: Florian G. Haas
: LINBIT Information Technologies GmbH
: Vivenotgasse 48, A-1120 Vienna, Austria

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