In relation to the issues i have been seeing about "can't create a stream from a metadata VDI, fall back to a base " after preforming a VM migration from one host to another i notice i also see the following in the SMLog.
Note: i also see this in the SMLog on the pool master after a VM migration even if i don't have snapshot delete enabled but simply have NBD + CBT Enabled. However the regular delta backup will proceed anyway and works fine in that case. (With snap delete disabled) With Snap delete i will see "can't create a stream from a metadata VDI, fall back to a base". Running the job again after this will produce no error in SMLog. Only after a VM migration between hosts will this appear.
Log snippit:
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: opening lock file /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: acquired /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ['/usr/sbin/cbt-util', 'get', '-n', '/var/run/sr-mount/16e4ecd2-583e-e2a0-5d3d-8e53ae9c1429/afd3edac-3659-4253-8d6e-76062399579c.cbtlog', '-c']
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] pread SUCCESS
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: released /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] Raising exception [460, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ***** generic exception: vdi_list_changed_blocks: EXCEPTION <class 'xs_errors.SROSError'>, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 111, in run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] return self._run_locked(sr)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 161, in _run_locked
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] rv = self._run(sr, target)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 326, in _run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] return target.list_changed_blocks()
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/VDI.py", line 757, in list_changed_blocks
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] "Source and target VDI are unrelated")
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ***** NFS VHD: EXCEPTION <class 'xs_errors.SROSError'>, Failed to calculate changed blocks for given VDIs. [opterr=Source and target VDI are unrelated]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 385, in run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] ret = cmd.run(sr)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 111, in run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] return self._run_locked(sr)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 161, in _run_locked
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] rv = self._run(sr, target)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/SRCommand.py", line 326, in _run
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] return target.list_changed_blocks()
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] File "/opt/xensource/sm/VDI.py", line 757, in list_changed_blocks
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] "Source and target VDI are unrelated")
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578]
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: closed /var/lock/sm/afd3edac-3659-4253-8d6e-76062399579c/cbtlog
Sep 17 21:07:40 xcpng-prd-03 SM: [1126578] lock: closed /var/lock/sm/16e4ecd2-583e-e2a0-5d3d-8e53ae9c1429/sr
Sep 17 21:07:40 xcpng-prd-03 SM: [1126556] FileVDI._snapshot for c56e5d87-1486-41da-86d4-92ede62de75a (type 2)
Sep 17 21:07:40 xcpng-prd-03 SM: [1126556] ['uuidgen', '-r']
Sep 17 21:07:40 xcpng-prd-03 SM: [1126556] pread SUCCESS