EDEVICEs are z/VM's way to provide that virtualization and hide the ugly details.... but in this case z/VM is simply supplying a path (FCP subchannel) and it's up to guest OS to do what it needs to do to connect to the storage using that path.
So to me the question would be - why aren't EDEVICEs being used? Scott Rohling On Fri, Sep 8, 2017 at 1:45 PM, Willemina Konynenberg <[email protected]> wrote: > To me, all this seems to suggest some weakness in the virtualisation > infrastructure, which seems odd for something as mature as z/VM. > > So then the follow up question would be: is the host infrastructure > being used properly here? Is there not some other (managable) way to > set things up such that all the ugly technical details of the underlying > host/san infrastructure is completely hidden from the (clone) guests, > and that the guests cannot accidentally end up accessing resources they > shouldn't be allowed to access? This should be the responsibility of > the host system, not of each and every single guest. > > To me, that seems a fairly basic requirement for any sensible virtual > machine host infrastructure, so I would think that would already be > possible in z/VM somehow. > > Willemina > > > On 09/08/17 22:28, Robert J Brenneman wrote: > >> Ancient history: http://www.redbooks.ibm.com/redpapers/pdfs/redp3871.pdf >> >> Without NPIV you're in that same boat. >> >> Even if you had NPIV you would still have to mount the new clone and fix >> the ramdisk so that it points to the new target device instead of the >> golden image. >> >> This is especially an issue for DS8000 type storage units that give every >> LUN a unique LUN number based on which internal LCU its on and the order >> it >> gets created. Storwize devices like SVC and V7000 do it differently: each >> LUN is numbered starting from 0000 and counts up from there for each host, >> so the boot LUN is always LUN 0x0000000000000000 for every clone and you >> don't have to worry about that part so much. >> >> The gist of your issue is that you need to: >> mount the new clone volume on a running Linux instance >> chroot into it so that your commands are 'inside' that cloned linux >> environment >> fix the udev rules to point to the correct lun number >> fix the grub kernel parameter to point to the correct lun if needed >> fix the /etc/fstab records to point to the new lun if needed >> ?? re-generate the initrd so that it does not contain references to the >> master image ?? >> >> ( I'm not sure whether that last one is required on SLES 12 ) >> >> On Fri, Sep 8, 2017 at 3:30 PM, Alan Altmark <[email protected]> >> wrote: >> >> On Friday, 09/08/2017 at 04:46 GMT, Scott Rohling >>> <[email protected]> wrote: >>> >>>> Completely agree with you .. I might make an exception if the only >>>> >>> FCP >>> >>>> use is for z/VM to supply EDEVICEs >>>> >>> >>> AND the PCHID is configured in the IOCDS as non-shared. >>> >>> 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/ >>> >>> >> >> >> -- >> Jay Brenneman >> >> ---------------------------------------------------------------------- >> 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/ >> >> > ---------------------------------------------------------------------- > 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/ > ---------------------------------------------------------------------- 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/
