On Mon, 25 Nov 2002, David Boyes wrote: > > > [.. .stuff about CSE ...] > > Does that actually work if the disk is online to both systems at the > > same time? I have visions of Linux not appreciating that the > > data on its > > ro volume is actually dynamic. > > The point of CSE is to allow a VM userid to log in on any system that is > part of the CSE complex and have it's normal mindisks and spool files > available to it. Note that spool sharing requires PVM, which does not > yet have a license for IFLs, even though it works fine, and there are > some significant setup implications to get CSE working in a local > context. The way it works is shown below. > > Say you have 2 systems bound together in a CSE complex, NODEA and NODEB > (either two separate boxes or two LPARs, etc). So, when you log on a > Linux system in a VM userid on NODEA, the minidisks containing the data > go R/W on NODEA and R/O everywhere else. There are still the consistency > problems because the mindisk directory is still updated in core just > like always. IF, however, you have a way of LINKing or detaching a > minidisk and signaling another system to pick it up, the "other" system > can be on some other node in the CSE complex. > > CSE is useful as a beginning for HA systems and shared DASD. It's not a > complete solution just yet, but it does handle a few of the harder > parts. Building something like GFS or GPFS on top of CSE would be an > intriguing possibility, if either could be taught a few new tricks about > how to hand the disks back and forth.
But does it actually work with Linux? Both Linux systems re caching data off the disk. I've not heard that _Linux_ supports it. Or if I have, I've forgotten. -- Cheers John. Join the "Linux Support by Small Businesses" list at http://mail.computerdatasafe.com.au/mailman/listinfo/lssb
