[Bug 1641078] [NEW] System cannot be booted up when root filesystem is on an LVM on two disks

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---Problem Description---
LVMed root file system acrossing multiple disks cannot be booted up 
  
---uname output---
Linux ntc170 4.4.0-38-generic #57-Ubuntu SMP Tue Sep 6 15:47:15 UTC 2016 s390x s390x s390x GNU/Linux
 
---Patches Installed---
n/a
 
Machine Type = z13 
 
---System Hang---
 cannot boot up the system after shutdown or reboot
 
---Debugger---
A debugger is not configured
 
---Steps to Reproduce---
 Created root file system on an LVM and the LVM crosses two disks. After shut down or reboot the system, the system cannot be up. 
 
Stack trace output:
 no
 
Oops output:
 no
 
System Dump Info:
  The system is not configured to capture a system dump.
 
Device driver error code:
 Begin: Mounting root file system ... Begin: Running /scripts/local-top ...   lvmetad is not active yet, using direct activation during sysinit 
  Couldn't find device with uuid 7PC3sg-i5Dc-iSqq-AvU1-XYv2-M90B-M0kO8V. 
 
-Attach sysctl -a output output to the bug.

More detailed installation description:

The installation was on a FCP SCSI SAN volumes each with two active
paths.  Multipath was involved.  The system IPLed fine up to the point
that we expanded the /root filesystem to span volumes.  At boot time,
the system was unable to locate the second segment of the /root
filesystem.   The error message indicated this was due to lvmetad not
being not active.

Error message:   
       Begin: Running /scripts/local-block ...   lvmetad is not active yet, using direct activation during sysinit 
       Couldn't find device with uuid 7PC3sg-i5Dc-iSqq-AvU1-XYv2-M90B-M0kO8V 
        Failed to find logical volume "ub01-vg/root" 
        
PV Volume information: 
physical_volumes { 

               pv0 { 
                       id = "L2qixM-SKkF-rQsp-ddao-gagl-LwKV-7Bw1Dz" 
                       device = "/dev/sdb5"        # Hint only 

                       status = ["ALLOCATABLE"] 
                       flags = [] 
                       dev_size = 208713728        # 99.5225 Gigabytes 
                       pe_start = 2048 
                       pe_count = 25477        # 99.5195 Gigabytes 
               } 

               pv1 { 
                       id = "7PC3sg-i5Dc-iSqq-AvU1-XYv2-M90B-M0kO8V" 
                       device = "/dev/sda"        # Hint only 

                       status = ["ALLOCATABLE"] 
                       flags = [] 
                       dev_size = 209715200        # 100 Gigabytes 
                       pe_start = 2048 
                       pe_count = 25599        # 99.9961 Gigabytes 


LV Volume Information: 
logical_volumes { 

               root { 
                       id = "qWuZeJ-Libv-DrEs-9b1a-p0QF-2Fj0-qgGsL8" 
                       status = ["READ", "WRITE", "VISIBLE"] 
                       flags = [] 
                       creation_host = "ub01" 
                       creation_time = 1477515033        # 2016-10-26 16:50:33 -0400 
                       segment_count = 2 

                       segment1 { 
                               start_extent = 0 
                               extent_count = 921        # 3.59766 Gigabytes 

                               type = "striped" 
                               stripe_count = 1        # linear 

                               stripes = [ 
                                       "pv0", 0 
                               ] 
                       } 
                       segment2 { 
                               start_extent = 921 
                               extent_count = 25344        # 99 Gigabytes 

                               type = "striped" 
                               stripe_count = 1        # linear 

                               stripes = [ 
                                       "pv1", 0 
                               ] 
                       } 
               } 


Additional testing has been done with CKD volumes and we see the same behavior.   Only the UUID of the fist volume in the VG can be located at boot, and the same message:  lvmetad is not active yet, using direct activation during sysinit 
Couldn't find device with uuid xxxxxxxxxxxxxxxxx  is displayed for CKD disks. Just a different UUID is listed.   
If the file /root file system only has one segment on the first volume,  CKD or SCSI  volumes, the system will IPL.  Because of this behavior, I do not believe the problem is related to SAN disk or multipath.   I think it is due to the system not being able to read the UUID on any PV in the VG other then the IPL disk.

** Affects: ubuntu-z-systems
     Importance: Medium
     Assignee: Dimitri John Ledkov (xnox)
         Status: Invalid

** Affects: s390-tools (Ubuntu)
     Importance: Undecided
     Assignee: Skipper Bug Screeners (skipper-screen-team)
         Status: Invalid


** Tags: architecture-s39064 bugnameltc-148452 s390x severity-critical targetmilestone-inin16041
-- 
System cannot be booted up when root filesystem is on an LVM on two disks
https://bugs.launchpad.net/bugs/1641078
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