On Wednesday, 03/17/2004 at 11:50 EST, "Davis, Larry" <[EMAIL PROTECTED]> wrote: > Should I be letting Linux instances, under z/VM, utilize Cylinder 0?
I would recommend never allowing any guest to write on cyl 0. If the guest writes a label that matches the label of any of your CP_OWNED packs, you could be in for a big surprise the next time you IPL. The one exception is if the persons doing the labelling are following the same procedures you do for choosing volume labels. Problems can be reduced by having hourly/daily checks of the volume labels to ensure no overlap. You have to actually read the volser; you can't use QUERY DASD or QUERY rdev because CP caches the volser when the device comes online. USER volumes are easily dealt with by simply ATTACHing to SYSTEM in AUTOLOG1 rather than having them in the USER_VOLUME list. But, then, I'm a Security Weasel, so I'm more paranoid than most... Alan Altmark Sr. Software Engineer IBM z/VM Development ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
