We are going a little bit crazy trying to figure out a process to initialize PAV capable volumes for our zLinux guests.
Because we assign disk packs to only one guest we are using the full-pack minidisk method of enabling HyperPAV (per page 469 in “The Virtualization Cookbook for IBM z/VM 6.3, RHEL 6.4, and SLES 11 SP3”). The problem that we’re having is how to hand off the task of initializing the disk volumes for zLinux with as little chance for error as possible. I don’t want to have our Linux/Unix admins to have to retype the volsers that we’ve already assigned to the disks. The chances of a finger check are too great and any errors are a significant problem since we depend (as does zVM) on volsers being unique across the system. When we create the guest we format and label the volumes using ICKDSF. According to the Cookbook one of the first steps in making the disk available to zLinux is to run a dasdfmt command against the disk. According to “Device Drivers, Features, and Commands on Red Hat Enterprise Linux 7”, dasdfmt has an option –k -k or --keep_volser keeps the volume serial number when writing the volume label (see VOLSER). Keeping the volume serial number is useful, for example, if the volume serial number was written with a z/VM tool and should not be overwritten. However, whenever we try to run dasdfmt with that option we get the following error [root@dcvml29 ~]# dasdfmt -b 4096 -y -v -k -f /dev/dasdf dasdfmt: VOLSER not found on device /dev/dasdf I’ve tried various kinds of formats CPVOL FMT MODE(ESA) UNIT(7625) VFY(0X0400) VOLID(VH2905) - RANGE(0,10016) INIT UNIT(7625) VFY(VH2905) VOLID(VH2905) - CYLRANGE(0,10016) - PURGE NOVALIDATE VTOC(000,01,14) INDEX(015,00,15) And using CPFMTXA but nothing I do writes a VOLSER that RedHat will find on the volume. The Cookbook implies (around that same page) but doesn’t come out directly to say that –k doesn’t work as designed. Do you know of any way that we can format a DASD volume on zVM and have the VOLSER be acceptable to zLinux? Any insights are most appreciated. George Shedlock Jr 10300 Ormsby Park Place [email protected] Louisville, KY 40223 T +1 502 560 3541 http://intranet.ds.global/technology/
