Eric if the file system is not clustered awared it would never work. the reason is very simple. a file system is a driver. one driver is a state machine running on machine 1 and the other is running on machine 2. there is no synch between the two. if u are a progmmer , try implement a userpace bitmap reader meaning, if machine 1 is the writer, whenever a file is created or modified , send the bitmap to machine 2 reader. i can give an xfs bitmap reader if u want . On 4/13/06, Jon Miller <jonebird@xxxxxxxxx> wrote: > Yeah, the Lustre FS looks very promising... I've even concidered the > CODA filesystem, but since I'll be implementing this solution where > management wants support they pay for, it will most likely be GFS as > my servers are RHAS 3.0 machines. > Thanks for the help, though. BTW, while I was trying to get my > _simple_ ext3 solution working, I tried using mount options such as > 'sync' and 'dirsync' but as you already know they didn't help. > Just for my own benefit, is the reason none of these options would > work is because all FS IO is ran through the VFS and that is where the > caching occurs? In particular, I want to say that the "buffer_head" > kernel buffer is the specific slab that is used for the caching? > > Thanks, > Jon > > On 4/13/06, Raz Ben-Jehuda(caro) <raziebe@xxxxxxxxx> wrote: > > may be lustre > > > > On 4/13/06, Erik Mouw <erik@xxxxxxxxxxxxxxxxxxxxx> wrote: > > > On Mon, Apr 10, 2006 at 05:24:34PM -0400, Jon Miller wrote: > > > > I have two machines which have redundant paths to the same shared scsi > > > > disk. I've had no problem creating the multipath'ed device md0 to > > > > handle my redundant pathing. But now I'd like to use a simple FS, such > > > > as ext3, mounted rw on the first machine and ro on the second machine. > > > > The idea is that the second machine, mounting the FS ro, would be able > > > > to read any new data being written in the FS. > > > > Everything has been rather easy to setup, but anything being created > > > > on the FS is not seen on the other machine with the FS mounted ro. > > > > That is, I can create a file on the first machine and I never see that > > > > file from the second machine until I remount the FS. > > > > At this point, I am actually trying to avoid GFS, OCFS, veritas > > > > clustered FS options as well as NFS. If there was a simple hack, that > > > > I'm missing, to enable the updates to the FS to be seen in realtime, > > > > then I'd actually prefer that method. > > > > Any help would be appreciated. > > > > > > I'm affraid the only way out is indeed GFS or OCFS. Those filesystems > > > are specifically designed to be mounted by several hosts and (should) > > > have caching and locking issues covered. > > > > > > > > > Erik > > > > > > -- > > > +-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 -- > > > | Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands > > > - > > > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > > > > > > -- > > Raz > > > -- Raz - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
