Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, I have a customer with large amounts of data (5 TB) which has to be backed up in a very short time frame and where the backup should have as low as possible impact on system performance during backup. And yes, budget is very limted. Failover and Cluster Features are not needed at this site. I have tested a lab setup where the customer data is mirrored to a second storage box with drbd. The drbd on the secondary node is mostly in Disconnected state to not degrade performance of the primary drbd Server. I have found out that the amount of customer data tat changes daily is not that big and that it only needs 15 minutes sync-time after reconnect until the drbds are fully in sync. Then i could snapshot the data on the second drbd and disconnect the drbds again. I can then backup the data from the secondary drbd box and have a lot of time for this and it does not have any performance impact on the primary and disconnected drbd storage. Even better: The second drbd box can be quite slow and crappy, it only has impact for the short sync time. I think this is a good and creative usage of drbd for certain use cases. What I want to know: is there anything wrong with running a drbd cluster where the second node is disconnected most of the time ? Will some memory or buffers run out of space or such things ? Is the performance of a disconnected drbd disk far slower than the performance of a native lvm volume ? Is there any other reason why I should not use this setup in this use case ? Thanks Christoph -- Christoph Adomeit GATWORKS GmbH Reststrauch 191 41199 Moenchengladbach Sitz: Moenchengladbach Amtsgericht Moenchengladbach, HRB 6303 Geschaeftsfuehrer: Christoph Adomeit, Hans Wilhelm Terstappen Christoph.Adomeit at gatworks.de Internetloesungen vom Feinsten Fon. +49 2166 9149-32 Fax. +49 2166 9149-10