On Thursday, 06/13/2002 at 10:53 EST, Mark Wheeler <[EMAIL PROTECTED]> wrote: > I have customers interested in clustering virtual Linux systems for high > availability. I have VM systems in two different buildings, connected via > ESCON CTCs. The idea is to set up pairs of Linux guests, one in each > building, with the absolute minimum hardware in between. One approach would > be to assign each pair of Linux guests its own CTC address pair, but I > could quickly run out of CTC addresses. Since the two systems already have > an ISFC connection, it would seem that Distributed IUCV would be an > interesting option. I'm hesitant about just setting "DISTRIBUTE IUCV YES" > in SYSTEM CONFIG because of concern about messing up all the traditional > IUCV applications (VM:Secure, VM:Backup, etc), so "DISTRIBUTE IUCV > TOLERATE" looks like a safer choice. > 1) Is it safe to assume that traditional IUCV applications will not be > affected if I turn on TOLERATE? > 2) Does the Linux IUCV driver support Distributed IUCV connections in > general? > 3) Does the Linux IUCV driver support Distributed IUCV connections when > running in TOLERATE mode, which I understand requires that the application > specify the system that it wants to talk to? If yes, how would that be > coded?
First, congrats to 3M on 100 years of bringing Things That Are Rough and Things That Stick (we tolerate 3M's other activities only so we continue to get sandpaper and post-its!) to the world! :-) 1) Yes. In TOLERATE mode, the app must be "D-IUCV"-aware and provide a non-null system name in the IUCV CONNECT plist. Apps that don't do that will stay on their own system. 2) Yes. The Linux IUCV driver specifies a null system name on the IUCV CONNECT, so it can connect to any user in the collection if DISTRIBUTE IUCV YES is specified. 3) No. See #2. To change it you would have to modify drivers/s390/net/netiucv.c to parse the system name out of the parms and specify it on the iucv_connect() call. Right now netiucv.c variable iucv_host is defined as a null constant. I could envision iucv=[systemname.]userid as the parm. Alan Altmark Sr. Software Engineer IBM z/VM Development
