Thank you Rick for your input. Here are some more experiments > > For FBA (including EDEV and SAN), use 'fdisk'. > (And forgive me for repeating some details that you already know.) > In my experience, the partition logic sees a default partition even when > one was not explicitly created. > I found that I could get rid of this ghost partition by explicitly > running 'fdisk' and writing an empty partition table. Then "dasda1" goes > away. > > > I did an experiment and created new small EDEV devices and linked them to two systems - original SLES12 (from DVD) and updated version of SLES12 In both cases running fdisk and saving the partition table did not get rid of “dasdb1” device. It’s as you said a ghost partition defined in fly by a dasd/fba driver. Nothing is being written to a disk. But creating a couple of dummy partitions and removing them afterwards does leave some stuff on the disk (I've dumped it with dd and looked closely) and it does get rid of that ghost partition! But a device is still not usable by LVM in updated SLES12. It still claims that there is a partition table signature found. The original SLES12 doesn't care! Lvm will be happy to create labels on it.
At some point I created a label on dasdb1 and then on dasdb. Than I've dumped first blocks of the dasdb and looked for ascii. I found both of the labels, just 2 sectors from each other So it seems like something has definitely changed and it is not possible to use and edev without this ghost partition while it was possible in DVD (ver 12.0.20141010) version of SLES12. Which may lead to big problems if someone who uses edev like this will do an update. Gregory > > ---------------------------------------------------------------------- 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/
