On 4/10/06, Ming Zhang <mingz@xxxxxxxxxxx> wrote: > On Mon, 2006-04-10 at 14:46 -0500, Eric Van Hensbergen wrote: > > On 4/10/06, Ed Wilts <ewilts@xxxxxxxxxx> wrote: > > > > > > The obvious question is why? What would this provide that the kernel > > > and file systems don't already provide? > > > > > > > Well, kernel provides in-memory page cache, not local disk page cache. > > There is some ongoing remote file system local disk cache work being > > done, but it applies primarily to AFS and NFS - not block-based > > transports such as iSCSI and AOE. The various cluster file systems > > may provide something more akin to this, but again, this doesn't > > really cover SAN technologies -- not in any sort of a generic way. > > Let me know if I'm missing something. > > still, what is the main benefit of this cache? what u mean "local disk > page cache"? use "local disk" as page cache or page cache for "local > disk" or something else? > Okay, I suppose I wasn't exactly clear. What I want is something that will let me use a local disk (or local disks) as a cache for a storage area network volume (or volumes). There are a variety of scenarios - my primary interest is in using it for large clusters with shared read-only volumes or with exclusive-access read/write volumes. So, local disk page cache is probably not the right terminology -- it is simply a local block cache for a remote block device. -eric -- dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel