That's handy to know. Another thing about rescuing some other guest's LUN, if (to avoid looking up where to echo the LUN's wwpn and LUN# to the /sys structures to put that LUN online) I use zfcp_disk_configure to put the LUN online, that command adds/updates files in /etc to automatically bring the LUN online during the next boot. By then the rescuing guest's unlikely to have the correct FCP subchannel anymore but my point is the /etc files now have some misleading info and it's one more thing to clean up. If on the down guest I can boot a read/only rescue system whose r/w files live temporarily in memory I avoid some hassle.
> -----Original Message----- > From: Linux on 390 Port [mailto:[email protected]] On Behalf Of > Alan Altmark > Sent: Thursday, June 25, 2009 3:55 PM > To: [email protected] > Subject: Re: Mounting root fs of one instance to another instance to > make repairs > > On Thursday, 06/25/2009 at 03:32 EDT, "Romanowski, John (OFT)" > <[email protected]> wrote: > > Some more pedantism: For both dasd and SCSI disks, booting a rescue > system on > > the downed zLinux server makes repairing the file easier: > > the VM userid already has access to the disk in question, no need to > LINK to or > > get the other userid zoned/masked to the downed server's LUN. > > It doesn't matter what user ID is used. The NPIV WWPN is assigned to > the > subchannel. ATTACH the sc to whatever guest you want. (The old > userid-based LUN Access Control authorization scheme is long gone.) > > Alan Altmark > z/VM Development > 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 This e-mail, including any attachments, may be confidential, privileged or otherwise legally protected. It is intended only for the addressee. If you received this e-mail in error or from someone who was not authorized to send it to you, do not disseminate, copy or otherwise use this e-mail or its attachments. Please notify the sender immediately by reply e-mail and delete the e-mail from your system. ---------------------------------------------------------------------- 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
