On Friday, 03/23/2018 at 12:25 GMT, Mariusz Walczak <[email protected]> wrote: > @Alan your explanation is interesting, but we reference those DASD labels on > zOS for backup purposes. If I understood correctly you recommend to forget > about the labels on VM and use real device numbers, which is a no-go.
I didn't mean that you forget about labels. They are still necessary. I meant that when a guest has access to the real label, it can change the label to match an existing label and potentially compromise your system. Unlike z/OS, CP doesn't stop and ask you at IPL time which volume to use when there are duplicates. He just notes that there are duplicates and chooses the one with the lowest device number (address). Today it's the right one. Tomorrow, maybe not. (Maybe the correct one is offline for some reason?) The steps I described are how you ensure the integrity of the system and its data. The old cross-your-fingers-and-hope method is SO last century, yet still in common use by both sysprogs and teenagers. Alan Altmark Senior Managing z/VM and Linux Consultant IBM Systems Lab Services IBM Z Delivery Practice ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 [email protected] IBM Endicott ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
