Hej Frank, On 09:08 Thu 13 Aug , Frank M. Ramaekers wrote: > I'm new to both SLES (12 in my case) and btrfs. I just recently > installed SLES 12 onto a 3390-9 (I had an additional 3390-9, but didn't > see a way to combine the two into a single fs). I want to add the other > 3390-9 to the btrfs (/) for expansion purposes. >
I have done the same thing on a test vm - adding a second DASD to a existing root-btrfs filesystem. In short: be very cautious. The btrfs-function works as you can find it in various help-texts, but the problem is, you change you root-fs and upon reboot the second DASD has to be whitlisted by the initrds so it can be used - and that is not yet supported afaik, even more so because the default disk-layout places the grub2 onto the same FS, and thus not even grub2 will be able to launch. The initrd will only know about the DASD that you have used initially to install the system. In my case the system would not boot anymore because the second DASD was still masked by cio-ignores and the kernel couldn't build the btrfs (no support for degraded raids). I have not found a solution that would cover this out-of-the-box in SLES 12 (that included rebuilding the initrd loaded by zipl and the one loaded by grub2). The dependency tracking doesn't seem to take btrf-volumes into account. Unless I missed something I'd advice against it. The official documentation that SUSE provides [1] suggests that LVM and DM-Raid are natively supported by it. [1] - https://www.suse.com/documentation/sles-12/stor_admin/data/stor_admin.html Beste Grüße / Best regards, - Benjamin Block -- Linux on z Systems Development / IBM Systems & Technology Group IBM Deutschland Research & Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz Geschäftsführung: Dirk Wittkopp / Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu 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/
