1. All vms with data on nfs Tintri storage take snapshot failed: 'The SR failed to complete the operation.'
2. The issue occurs on 3 pools with the same storage attached.
3. Vms on local storage can take snapshot successfully.

Extract the RPMs by downloading the XS71ECU2043 ISO and double clicking it in Windows to mount it, the sm-1.17.0-xs.2+1.0_71.2.8.x86_64.rpm is found in the Packages folder.
1. To copy sm-1.17.0-xs.2+1.0_71.2.8.x86_64.rpm to the folder /tmp under each pool host
2. To remove the dependent update package
yum remove update-XS71ECU2065
3. Downgrade to sm-1.17.0-xs.2+1.0_71.2.8.x86_64.rpm
cd /tmp ; yum downgrade sm-1.17.0-xs.2+1.0_71.2.8.x86_64.rpm

---

Problem Cause

The Tintri NFS storage doesn't support hardlink feature which is introduced by the hotfix XS71ECU2065. So SM code failed to call hardlink function.
Feb 10 18:31:44 xxxx SM: [26121] FileVDI._link /var/run/sr-mount/c4863fb7-6eb1-3c2c-7b69-d82b3f909594/6a357f14-a22f-4240-959c-b46699eed4f1.vhd to /var/run/sr-mount/c4863fb7-6eb1-3c2c-7b69-d82b3f909594/3743d74a-a032-4e07-9c9e-b0b76988090c.vhd
Feb 10 18:31:44 xxxx SM: [26121] Unpause request for 6a357f14-a22f-4240-959c-b46699eed4f1 secondary=None
Feb 10 18:31:44 xxxx SM: [26121] Calling tap-unpause on host OpaqueRef:a478b105-c721-0d74-a79f-f17ec3d8af51
Feb 10 18:31:44 xxxx SM: [26121] lock: released /var/lock/sm/c4863fb7-6eb1-3c2c-7b69-d82b3f909594/sr
Feb 10 18:31:44 xxxx SM: [26121] ***** generic exception: vdi_snapshot: EXCEPTION , [Errno 524] Unknown error 524
Feb 10 18:31:44 xxxx SM: [26121] File "/opt/xensource/sm/SRCommand.py", line 110, in run
Feb 10 18:31:44 xxxx SM: [26121] return self._run_locked(sr)
Feb 10 18:31:44 xxxxx SM: [26121] File "/opt/xensource/sm/SRCommand.py", line 159, in _run_locked
Feb 10 18:31:44 xxxx SM: [26121] rv = self._run(sr, target)
Feb 10 18:31:44 xxxx SM: [26121] File "/opt/xensource/sm/SRCommand.py", line 249, in _run
Feb 10 18:31:44 xxxx SM: [26121] return target.snapshot(self.params['sr_uuid'], self.vdi_uuid)
Feb 10 18:31:44 xxxx SM: [26121] File "/opt/xensource/sm/FileSR.py", line 691, in snapshot
Feb 10 18:31:44 xxxx SM: [26121] return self._do_snapshot(sr_uuid, vdi_uuid, snap_type, secondary)
Feb 10 18:31:44 xxxx SM: [26121] File "/opt/xensource/sm/FileSR.py", line 730, in _do_snapshot Feb 10 18:31:44 xxxx SM: [26121] return self._snapshot(snap_type)
Feb 10 18:31:44 xxxx SM: [26121] File "/opt/xensource/sm/FileSR.py", line 797, in _snapshot
Feb 10 18:31:44 xxxx SM: [26121] self._link(src, newsrc)
Feb 10 18:31:44 xxxx SM: [26121] File "/opt/xensource/sm/FileSR.py", line 740, in _link
Feb 10 18:31:44 xxxxx SM: [26121] os.link(src, dst)