Xen VMs Tab will be empty due to disk name is lengthy

Xen discovery issue: Virtual Machines tab will be empty in the host snapshot page due to the Disk name is exceeded more than 100, and the below exception will be found in stderr log

Caused by: java.sql.SQLException: Batch entry 21 INSERT INTO XenSRVDIProps (VDI_ID,UUID,NAME,SR_ID,LOCATION,MANAGED,VIRTUAL_SIZE_MB,PHYSICAL_UTIL_MB,SHARABLE,TYPE) VALUES ('50000000697','1593ad2c-f24a-4ab6-8432-4febdf0bac46','en_windows_server_2008_r2_standard_enterprise_datacenter_and_web_debug_checked_build_x64_dvd_408075.iso','50000000627','en_windows_server_2008_r2_standard_enterprise_datacenter_and_web_debug_checked_build_x64_dvd_408075.iso','1','2880','2880','0','user') was aborted. Call getNextException to see the cause.

Please follow the below steps to fix

1. delete both master and slave hosts
2. run the below queries

PGSQL:

ALTER TABLE XenSRVDIProps ALTER NAME TYPE VARCHAR(450)
ALTER TABLE XenSRVDIProps ALTER LOCATION TYPE VARCHAR(450)

MSSQL:

ALTER TABLE XenSRVDIProps ALTER COLUMN NAME VARCHAR(450)
ALTER TABLE XenSRVDIProps ALTER COLUMN LOCATION VARCHAR(450)

3. restart opmanager service and add the master xen.