On 2/18/09 2:23 PM, "Mark Post" <mp...@novell.com> wrote: > When the DASD driver initializes, particularly in an LPAR, which devices do > you want it to pay attention to? Unlike most distributed systems, an LPAR can > be set up to "see" all the devices that are attached to the box. Those > devices can come and go rather dynamically. For Linux, this presents a > problem, since device names until just recently, were assigned based on the > order in which they were detected, or in the order specified in the DASD > driver parameters.
Doesn't udev give us a way to cope with that now? > Additionally, you don't _want_ Linux to try to look at all the devices out > there. In some shops, it can take forever for Linux to come up because it's > trying to interrogate thousands of devices to figure out what they are. After > that, a simple mistake by someone running as root could wipe out a DASD volume > that doesn't really have anything to do with Linux. I'd argue that that's pilot error. The code is doing exactly what it was told; it's counting what is present. Since best practice is that unnecessary stuff is NOT in the LPAR definition, solution is clear. > You can overcome some of this by telling the kernel to ignore ranges of device > numbers. That value gets stored in the boot parms, which are written out by > zipl. (There's no equivalent to grub that will read a parm file at boot > time.) So, if your I/O config changes, you still need to re-run zipl. Time to produce a SALIPL or DCSS compatible version of the grub loader or the netboot code.... Hmm. One could argue that CMS fills that role under VM. I wonder if we could write a module that was kind of like the Intel 'linload' tool. Would fix most of the cases, and a SALIPL version that could handle the LPAR crowd would take a bit longer. ---------------------------------------------------------------------- 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
