On Fri, 18 Sep 2009 10:35:22 +0200 Peter Gervai <grinapo at gmail.com> wrote: > Funny thread we have. > > Just a sidenote on the last week part about userspace cannot lock up > the system: blocking resource waits / I/O waits can stall _all_ disk > access, and try to imagine what you can do with a system without disk > access. Obviously, you cannot log in, cannot start new programs, > cannot load dynamic libraries. Yet the system pings, and your already > logged in shells may function more or less, especially if you have a > statically linked one (like sash). > > As a bitter sidenote: google for 'xtreemfs', may be interesting if you > only need a shared redundant access with extreme network fault > tolerance. (And yes, it can stall the system, too. :-)) I would not want to use it for exactly this reason (from the docs): ----------------------------- XtreemFS implements an object-based file system architecture (Fig. 2.1). The name of this architecture comes from the fact that an object-based file system splits file content into a series of fixed-size objects and stores them on its storage servers. In contrast to block-based file systems, the size of such an object can vary from file to file. The metadata of a file (such as the file name or file size) is stored separate from the file content on a Metadata server. This metadata server organizes file system metadata as a set of volumes, each of which implements a separate file system namespace in form of a directory tree. ----------------------------- That's exactly what we don't want. We want a disk layout that is accessible even if glusterfs (or call it the "network fs") has a bad day and doesn't want to start. > Another sidenote: I tend to see FUSE as a low-speed toy nowadays. It > doesn't seem to be able to handle any serious I/O load. Really, i can't judge. I haven't opened (this) pandora's box up to now ... > -- > byte-byte, > grin -- Regards, Stephan
