------- Comment From thorsten.di...@de.ibm.com 2016-07-13 11:52 EDT------- Hmm, just one hour ago the s390-tools maintainer submitted a patch for the manpage of cio_ignore to clarify that the example command "cio_ignore -u -k" modifies(!) the current cio_ignore blacklist. It was not obvious until today, that it really modifies something!
What does it mean: 1. Under z/VM, if somebody had invoked "cio_ignore -u -k" via installation of kdump-tools, performs no reboot AND attaches additional CCW devices, they will not show up in the channel subsystem (e.g. via lscss) until they are unblacklisted (e.g. via cio_ignore -r <busid>) 2. Similar for LPAR, if you define additional CCW devices via dynamic I/O configuration change in HCD. 3. If someone performs a "cio_ignore -p" after invoking "cio_ignore -u -k" (e.g. via installation of kdump-tools), the change becomes effective and visible also for existing unused devices, and all unused CCW devices are blacklisted and no more visible. 4. After a reboot, the cio_ignore blacklist is concurrent to what has been specified via kernel parameter line. (Which means: Everything is fine again.) My recommendation: 1. Go ahead with the actual implementation as of today, since it is worth to have a kdump when required, even with the above misbehaviour (which can be worked around). 2. When a new version of cio_ignore (within s390-tools) is available, you should pick up this new s390-tools version and also fix the postinst script in kdump-tools package picking by adjusting the cio_ignore parameters. We will open a new bug to fix the postinst script again, when an updated version of s390-tools is available. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to makedumpfile in Ubuntu. https://bugs.launchpad.net/bugs/1570775 Title: makekdump should re-exec with cio_ignore on s390x Status in Ubuntu on IBM z Systems: Fix Released Status in makedumpfile package in Ubuntu: Fix Released Status in makedumpfile source package in Xenial: In Progress Bug description: As per https://bugs.launchpad.net/ubuntu/+source/makedumpfile/+bug/1564475/comments/19 We should re-exec with cio_ignore lines. As per report there, it should result in lowered required crashdump setting. Hypothetically, one should be able to test this imperially by lowering crashdump memory settings until kdump does not succeed anymore. And then generated and append `cio_ignore -k -u` to the KDUMP_CMDLINE_APPEND= and see that kdump starts working again with a lower memory usage. Once this is developed / verified / tested, we should probably SRU this back to xenial. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1570775/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
