On 05/17/2012 03:40 PM, MORITA Kazutaka wrote: > I thought that one advantage of the simple_store driver was that it > uses a syscall link() to copy objects from local older epochs to the > current epoch, so we could avoid many I/Os in the recovery process. > However, it seems that the link operation of the farm driver is not > called at all on my environment. Does Farm do the recovery process in > the different way from the simple_store driver? farm_link() will be called for multiple nodes events and in a very unusual corner cases. Actually, for the case you describe Farm works in a more optimal way: there isn't any operations for the object that isn't to be migrated to other nodes, save a system call of link() than simple store. This contributes to Farm to outperform simple store for recovery, because most objects are not to be migrated at all for a recovery. Thanks, Yuan |