Hi Steffen It was a wonderful reference and I was able to add it without difficulty
On Mon, Sep 12, 2022, 7:28 PM Steffen Maier <ma...@linux.ibm.com> wrote: > Hi Jake, > > On 9/12/22 11:06, Jake Anderson wrote: > > I must confess that I have little knowledge about Multipathing but still > > based on my research below is what I understood > > > > My storage team has given a LUN ID of 500g > > > > So as per df -TH > > > > I see > > /dev/mapper/bradvg2-u03_lv is mounted on /u03 > > > > So similarly I have to create another mount point with /u04 > > > So If my understanding is correct I need to run multipath -d to scan the > > newly LUN added. > > It depends on whether you are using zfcp automatic LUN scan or not. > > https://public.dhe.ibm.com/software/dw/linux390/lvc/zFCP_Best_Practices-BB-Webcast_201805.pdf#page=20 > > https://public.dhe.ibm.com/software/dw/linux390/lvc/zFCP_Best_Practices-BB-Webcast_201805.pdf#page=21 > https://www.ibm.com/docs/en/linux-on-systems?topic=devices-configure > > If so (and the storage already mapped the volume to the host, of course), > you only need to trigger a LUN scan for Linux to dynamically find the new > paths > to the volume. That can be "rescan-scsi-bus.sh -a" or more directly (I > typically prefer this): > > https://www.ibm.com/docs/en/linux-on-systems?topic=scanning-trigger-lun-scan > > > Then do echo the new LUN ID to the device driver > > The apply changes to /etc/zipl.conf > > If you don't use zfcp automatic LUN scan, then you have to explicitly > configure > multiple paths to the new volume presistently in Linux. > The volume usage sounds like it's a data volume, i.e. not part of the root > file > system, so we don't touch /etc/zipl.conf, but only /etc/zfcp.conf. > > > https://public.dhe.ibm.com/software/dw/linux390/lvc/zFCP_Best_Practices-BB-Webcast_201805.pdf#page=23 > => > > https://www.ibm.com/docs/en/linux-on-systems?topic=devices-manually-configured-fcp-luns > => > > https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/performing_a_standard_rhel_8_installation/configuring-a-linux-instance-on-ibm-z_installing-rhel#fcp-luns-that-are-not-part-of-the-root-file-system_configuring-a-linux-instance-on-ibm-z > > In either case, a running multipathd ensures the new LUN paths are > automatically assembled into a new multipath device representing your new > volume. > > https://public.dhe.ibm.com/software/dw/linux390/lvc/zFCP_Best_Practices-BB-Webcast_201805.pdf#page=15 > > https://public.dhe.ibm.com/software/dw/linux390/lvc/zFCP_Best_Practices-BB-Webcast_201805.pdf#page=16 > > You can then prepare the new volume as you did for your already existing > LVM > PhysicalVolume(s) within VolumeGroup bradvg2, so likely something like > pvcreate > on the new multipath device (or on a partition thereof). > > LVM in recent Linux distributions automatically ignores individual single > paths > to a volume and makes use of multipath devices instead when scanning > PhysicalVolumes. > Older distributions might need an explicit LVM filter to accomplish this. > > https://public.dhe.ibm.com/software/dw/linux390/lvc/zFCP_Best_Practices-BB-Webcast_201805.pdf#page=46 > > FYI: In case you happen to run RHEL 9.x, you would instead have to deal > with > the new LVM device filter (different from above-mentioned LVM filter): > The RHEL installer "anaconda" disables auto PV scan by populating > /etc/lvm/devices/system.devices, so the user needs to add new PVs by means > of > "lvmdevices --adddev ...". > https://bugzilla.redhat.com/show_bug.cgi?id=2002550#c0 > > https://sourceware.org/git/?p=lvm2.git;a=commit;h=83fe6e720f42711ff183a66909b690b726702f58 > > > Then perform lv addition > > > > Is my understanding correct? Could someone please be kind to share the > > steps of adding the newly added LUN ID to an existing LV ? > > Your above steps with a new separate mount point, do not sound like you > would > add the new physical volume to an existing LVM VolumeGroup, which would be > another possibility. > > https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html-single/configuring_and_managing_logical_volumes/index#modifying-the-size-of-a-logical-volume_configuring-and-managing-logical-volumes > > > -- > Mit freundlichen Gruessen / Kind regards > Steffen Maier > > Linux on IBM Z and LinuxONE > > https://www.ibm.com/privacy/us/en/ > IBM Deutschland Research & Development GmbH > Vorsitzender des Aufsichtsrats: Gregor Pillen > Geschaeftsfuehrung: David Faller > Sitz der Gesellschaft: Boeblingen > Registergericht: Amtsgericht Stuttgart, HRB 243294 > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www2.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www2.marist.edu/htbin/wlvindex?LINUX-390
