On 7/2/20 5:32 PM, Martha McConaghy wrote: > I've run into something that is a bit beyond my Linux skills at this point. > So, I could use some advice. > > I have several RHEL 7 servers running on z/VM that are booting from SAN LUNs, > not ECKD. That isn't our normal practice, so it is different for me. I use > LOADDEV to define the port and LUN, and dedicate the device addresses to each > server. (All are using NPIV addressing and are zoned to a DS8870 on the > SAN.) Here is what one of the directory entries looks like: > > IPL 2000 > LOADDEV PORT 500507630628D700 > LOADDEV LUN 4000400700000000 > MACHINE ESA 4 > OPTION CHPIDV ONE > DEDICATE 2000 5000 > DEDICATE 3000 6000 >
-snip- > I don't know what to do with this situation, though, to get full use of the > 2nd fabric. First there is the IPL issue...how can I have an alternate IPL > address if 2000 doesn't work? Then, there is the issue of Linux once it > boots...not sure how to get multipath drivers introduced after the boot > process is already done. The LUN contains the operating system as well as > data. The IPL issue is the bigger problem. Since IPL is a CP command, if it fails, you're back in CP mode. So, no scripting of multiple attempts. You'll need to issue a different LOADDEV command to specify the other WWID and LUN to try the second path. Perhaps even IPL from the other FCP adapter. I don't believe that can be automated without having something like a SECUSER watching and trying different things if it fails. For the multipathing, you're probably going to need to enable the multipathd service, and them rebuild your initrd so that it gets started there, before your file systems get mounted. Not being familiar with the exact details of Red Hat's setup, all I can say is the commands will be something like: sysctl enable whateverthenameofthemultipathingsservice is, followed by the dracut with whatever parameters normally get used. I don't know that dracut will figure out it should include support for multipathing in the initrd or not. That may be something to run a Google search on. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www2.marist.edu/htbin/wlvindex?LINUX-390
