Mo Maison <[email protected]> writes: > Hello, > > I have read the referenced thread with great interest, > and I have a related question. > > If we replace NAS with SAN (SAN is basically a remote > block device). > If a single server mounts the SAN partition, and a single > derby server is run on this server, I guess we shouldn't > encounter any trouble, should we ?
Derby uses a write-ahead log to guarantee that committed transactions are persisted. If the log device is on the network storage, you need a guarantee that the log write operations are actually persisted. Similarly, for safe operation one needs to disable disk cache in the operating system for the log device. Cf. http://db.apache.org/derby/docs/10.9/adminguide/cadmindbintegrity.html Dag > > Regards, > > M. Maison > > > On 18/07/2012 14:48, Rick Hillegas wrote: >> On 7/18/12 1:56 AM, Santiago Miguel wrote: >>> Hi, >>> >>> I work in a french company which provides secure online file >>> management services (SaaS solutions). >>> >>> In one of our applications (backup software), in case of a large >>> file, we cut it into blocks and we use a Derby db in order to >>> maintain the block indexes. These Derby dbs (version 10.5.1.1) are >>> stored on a NAS (cluster Isilon NL series) shared between >>> webservers. The derby db is directly acceded on NAS and it is >>> thread safe. >>> Everyday, we are observing many Derby db corruptions (Unknown page >>> format at page Page(524,Container(0, 1024))) and these dbs are no >>> longer usable. >>> >>> I join the derby log file corresponding to the last night on 1 >>> webserver. >>> Thanks in advance for your help. >>> >>> Best regards, >>> Miguel Santiago >>> >> Hi Miguel, >> >> The following email thread may shed light on the problems you are >> seeing: >> http://old.nabble.com/Client-server-plus-network-storage-of-database-files-td19565143.html >> >> Hope this helps, >> -Rick >>
