Symptoms

Data Domain Virtual Edition (DDVE) systems may report that the Data Domain File System (DDFS) either is not available or does not exist. For example: sysadmin@localhost# df Active Tier: Resource Size GiB Used GiB Avail GiB Use% Cleanable GiB ---------------- -------- -------- --------- ---- ------------- /data: pre-comp - - - - - /data: post-comp - - - - - /ddvar 49.2 1.6 45.1 3% - /ddvar/core 158.5 0.2 150.2 0% - ---------------- -------- -------- --------- ---- ------------- The filesystem is unavailable at this time. This keeps the file system from being enabled and prevents access to data stored on the appliance. Note that: Data disks used by DDFS are stamped with the serial number of the system.When the DDVE scans its disks (for example, during boot), the system checks to see if the disk contains DDFS data. If it does, the system checks whether the serial number on the disk matches that of the current system.Disks that do hold DDFS data but have a different serial number than the system are marked as "foreign" and are not available for use. In this scenario, the appliance believes that the disks may correspond to another Data Domain system. As a result, if the serial number of the DDVE changes, all data disks are marked as foreign and the file system can no longer be enabled. For example: A DDVE has an enabled file system and serial number as follows: sysadmin@localhost# system show serialno Serial number: AUDXXXXXXXXX System software-id: Not available sysadmin@localhost# fi st The filesystem is enabled and running. An event takes place that forces the DDVE to reboot and generate a new serial number: sysadmin@localhost# system show serialno Serial number: AUDYYYYYYYYY System software-id: Not available All data disks are now marked as foreign and are not available for use: sysadmin@localhost# disk show state Dev 1 2 3 4 --- ------------ 1-4 Y Y O O --- ------------ Legend State Count ------ -------------- ----- O Foreign Device 2 Y System Device 2 ------ -------------- ----- Total 0 disks and 4 devs This causes the system to report that no file system exists and prevents the file system from being enabled: sysadmin@localhost# fi st The filesystem doesn't exist. sysadmin@localhost# fi enable **** The filesystem doesn't exist. Create the filesystem and try again.

Cause

The scenario described by this document - a change of DDVE serial number - generally occurs after some kind of unexpected operation such as: Sudden power off or forced reset of the DDVE or hypervisorSudden loss of connectivity to storage hosting the underlying virtual disk files and virtual machine configuration

Resolution

To determine whether the system serial number has changed (and so whether that is the cause of disks being marked as foreign): Obtain the current system serial number: sysadmin@localhost# system show serialno Serial number: AUDYYYYYYYYY System software-id: Not available Compare this to the serial number reported in historic autosupports from the same system: GENERATED_ON=Thu Dec 1 06:13:41 PST 2016 GENERATED_EPOCH_TIME=1480601621 TIME_ZONE=US/Pacific VERSION=Data Domain OS 6.0.0.20-547375 SYSTEM_SERIALNO=AUDXXXXXXXXX <=== NOTE CHASSIS_SERIALNO=AUDXXXXXXXXX MODEL_NO=DD VE Version 3 SYSTEM_SWID=Not available HYPERVISOR_TYPE=VMware ESXi 5.5.0 HOSTNAME=localhost.localdomain In this scenario, it is necessary to update the serial number on data disks to match the new serial number of the DDVE appliance. This allows the system to recognize that the disks are usable and correspond to the current system, and so enable the DDFS file system. For assistance with this, contact your contracted support provider and open a new service request.

Support Cases