Current implementations of NFS on Linux have a decent lock mechanism (as far as I know). You'll have to check your NAS device how does it handle NFS locking. But, if your NFS device is a complete box and not just a disk array with an ethernet card, you will be better creating a small client-server protocol over TCP. Darío
On Dec 19, 2007 6:04 AM, Trilok Soni <[EMAIL PROTECTED]> wrote: > Hi John, > > On Dec 18, 2007 11:53 PM, John Stanton <[EMAIL PROTECTED]> wrote: > > Sqlite depends upon POSIX file locks. It is no better or no worse than > > the POSIX lock implementation on your platform. > > Thanx for the reply. My platform is based on Linux running on ARM9, with > having 128MB of the flash on it. The captured video from analog/IP camera > will be stored on the NAS storage device connected to it through network, > which > gets mounted to the filesystem using NFS. So, the database file containing > these > videos meta information will be stored on NAS device, not on the flash > partition, > as flash is used to keep programs binaries and the size constraint. > > > > > We use Sqlite in a multi-user environment without dependency oin the > > POSIX locks by embedding it in a server using HTTP when it is on a > > remote machine. We get the small footprint and simoplicity of Sqlite > > and get no multi-user glitches regardless of platform. > > I am not able to understand, what you mean here by "embedding sqlite in a > server using HTTP when it is on a remote machine". In our project scenario, > we do have remote interface of this platform using embedded webserver running > on the device (e.g. boa/lighthttpd/webapp) and we want to show various > information > about these videos on the webpage by searching this file database > residing on the NAS. > > Only confusion for selecting SQLite came here is, because we are not storing > this database on the local flash on the device, but on the NFS mounted > NAS device, > which gets accessed/configured through web-interface provided by the > device through > some embedded webserver as explained in the earlier paragraph. And > SQLite FAQs I have > pointed mentions that there could be problem in accessing the database > over the NFS, > this is where I got confused and unable to decide to go for SQLite or not. > > -- > --Trilok Soni > > > > > > > > > Trilok Soni wrote: > > > Hi, > > > > > > I am evaluating SQLite for the design of the surveillance camera/DVR > > > product based on Linux, which stores its captured > > > analog/IP camera streams to the NAS storage device(s). To facilitate > > > faster search/scanning of those media files > > > containing many days of videos spread over multiple files, we plan to > > > keep the metadata of those videos > > > in some file format/database stored on NAS itself, so that > > > search/analysis mechanism just go through this > > > database to locate exact file with some search criteria like > > > time/data/camera/alarms/events etc. > > > > > > While reading the SQLite documentation I came to following FAQ, where > > > it lists that SQLite as application file format, > > > may not scale well to the NFS/Neworked attached drives due to the > > > locking problems. > > > > > > http://www.sqlite.org/faq.html > > > Refer 5th question. > > > (5) Can multiple applications or multiple instances of the same > > > application access a single database file at the same time? > > > > > > Is there any other way to work around this problem and use SQLite as > > > application file format in the above scenario. See that Linux > > > will run on the ARM9 having video processing done on specialized DSP. > > > > > > > > > ----------------------------------------------------------------------------- > > To unsubscribe, send email to [EMAIL PROTECTED] > > ----------------------------------------------------------------------------- > > > > > > ----------------------------------------------------------------------------- > To unsubscribe, send email to [EMAIL PROTECTED] > ----------------------------------------------------------------------------- > > ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
