Data Domain: Adding External Storage Capacity (ES30/DS60) while the System is online

Guide to minimise system downtime & keep filesystem enabled during a capacity upgrade.
Adding storage to a Live (powered on / FS UP) DD system is supported, however, extra care must be taken to ensure SAS/Pathing redundancy & failover is utilised to facilitate the addition of the new Shelf/shelves.
Failure to maintain connectivity to the existing storage during the addition of new shelves will result in downtime until the connections to storage can be recovered. 
CAUTION: Once an enclosure is added to a Tier it cannot be removed without destroying the file system.

Before physically connecting the new storage:

1. Verify that the system has the required Hardware config to support the additional expansion: 

2. Verify that there are no connection path issues (Single/Missing path alerts to any disk or enclosures).

3.  Required Capacity Licenses have been validated & added to the system  

Tips to maximize system Uptime during shelf upgrade:

• only work on ONE SAS HBA path at a time 
• For ES30/FS15 Enclosures: Allow at least 2 minutes between each Cable removal or insertion on the head unit SAS HBA ports.
• For DS60 Enclosures: Allow at least 8 minutes between each Cable removal or insertion on the head unit SAS HBA ports.
• Utilize available/free HBA slots to add the new storage enclosure/s (if possible)
• Do NOT mix different enclosure types on the same SAS path
• Do NOT exceed SAS chain lengths
• Refer to the relevant ES30/DS60 HW Guides for cabling topology & standards

1. Install the new external enclosure in the rack. Do not add the SAS cables yet.
2. Power up both power supplies on the new enclosure and wait for the LCC (Link Controller Cards) to initialise - approx 5 mins.
3. Cable the new shelf by doing the following:

4. Verify Enclosure connections, topology & disk state (Ref: 448322) 

5. Before adding disks to Volume and expanding the filesystem, it is recommended to run SAS diagnostics (Internal KB) to verify the enclosure topology.

6. Add the new enclosures to the required storage tier:
   
      # storage add tier {active | archive | cache | cloud} enclosure  <enclosure-id> 
       e.g # storage add tier active enclosure 5 
   
   Note: The enclosure-id is always 2 for the first added shelf and 3 for the second. The Data Domain system controller always has the enclosure-id of 1 (one).
             The newly added disks state will change to 'Available' (v) on the #disk show state command .
             

7. Expand the filesystem to include the newly added storage:
   
   # filesys expand

8. Verify the additional storage & disk status:
   
   #  storage show all
   #  filesys show space
   #  disk show state

9. Verify that the shelf is properly connected and functioning by running the following command on each enclosure path:
    
   # enclosure test topology <port> duration 1

10. Verify the state of the file system and disks by entering:
    
     #  filesys status

For detailed information on the addition of storage enclosures please see the relevant Hardware Guides listed below.
Additional information on licensing can be found in the relevant 'DDOS Admin Guide'.
If your problem persists after executing the steps in this article, please contact your contracted support provider, Gather a Support Bundle, and Create a service request

REFERENCE

- Data Domain DS60 Shelf Expansion Hardware Guide
- Data Domain ES30 Expansion Shelf and FS15 SSD Shelf Hardware Guide
- Troubleshooting Adding a Shelf
- Data Domain: System Memory Requirements and Expanded Storage Configurations 
- Data Domain Operating System 6.1 Administration Guide