>>> On 1/30/2017 at 09:19 AM, Michael J Nash <miken...@us.ibm.com> wrote:
> Greetings Mark, thank you for your reply. > Please explain the reasoning for disabling cio_ignore. > The reason I would not want to do this is because these guest systems may > be used for IPL of different distributions and/or releases. > I may IPL a SUSE 12, Red Hat 6.7, or a Red Hat 7.2 system. Having disks > visible used by other systems may cause problems. > Also, LVM volumes may conflict with naming conventions, For example: both > systems using the same volume group name. The cio_ignore feature was introduced primarily for LPAR installations. It helps speed up booting because the kernel doesn't try to enumerate every single device it can find. For z/VM environments that have relatively very few devices available, it's not needed. I can't speak for RHEL systems, but I think it's pretty much the same as for SLES. That is, unless you make a device persistently online, it's not going to come online by itself, so you shouldn't run into problems with LVM, extraneous DASD volumes being online, etc. Disabling cio_ignore in a guest means that people won't be constantly tripping over it when it's something they've not had to do for over 15 years. There are a number of things that you have to remember to do yourself when cio_ignore is active if you're not using YaST to do things. In general, it's a PITA for guests. Mark Post ---------------------------------------------------------------------- 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/
