Data Domain: Current cache tier size is less than what the system is licensed for

If the installed DataDomain Cache Tier capacity does not match the licensed Cache Tier capacity, then the following alert is generated:

Alert: WARNING Storage EVT-STORAGE-00025: Current cache tier size is less than what the system is licensed for.

There is a mismatch, which can be confirmed by doing the following:

1. Confirm Cache Tier capacity license:

elicense show licenses

Sample output:

Capacity licenses: 
##   Feature            Shelf Model   Capacity     Mode              Expiration Date 
--   ---------------    -----------   ----------   ---------------   --------------- 
1    CAPACITY-ACTIVE    DS60          130.96 TiB   permanent         n/a 
2    SSD-CAPACITY       n/a           5.82 TiB     permanent         n/a 
3    CLOUDTIER-CAPACITY n/a           272.84 TiB   permanent         n/a 
--   ---------------    -----------   ----------   ---------------   --------------- 
Licensed Active Tier capacity: 130.96 TiB* 

* Depending on the hardware platform, usable filesystem capacities may vary.

In this example, the licensed Cache Tier capacity is 5.82 TiB.

2. Confirm current Cache Tier capacity:

storage show all 

Sample output:

Active tier details: 
Disk 	Disks 				       Count 	Disk Additional 
Group						       Size Information 
-------------------------------------------------------------------- 
dg4 	2.7-2.9, 2.19-2.21, 2.31-2.33, 	14 	3.6 TiB 			
	2.43-2.45, 2.55-2.56 
dg3 	2.4-2.6, 2.16-2.18, 2.28-2.30, 	14 	3.6 TiB 
	2.40-2.42, 2.52-2.53 
dg2 	2.1-2.3, 2.13-2.15, 2.25-2.27, 	14 	3.6 TiB 
	2.37-2.39, 2.49-2.50 
(spare) 2.51 				        1 	3.6 TiB 
(spare) 2.54 				        1 	3.6 TiB 
(spare) 2.57 				        1 	3.6 TiB 
-------------------------------------------------------------------- 
Current active tier size: 130.9 TiB 
Active tier maximum capacity: 654.8 TiB 

Disk 	Disks 				Count 	Disk Additional 
Group						Size Information 
-------------------------------------------------------------------- 
dg1 	1.5-1.9 			5 	745.2 GiB 
-------------------------------------------------------------------- 
Current cache tier size: 3.6 TiB 

In this example, the physical cache tier size is reported as 3.6 TIB. (745.2 GiB x 5)

3. Confirm the number of SAS-SSD available in the System:

disk show hardware 

Sample output:

Disk Slot Manufacturer/Model       Firmware Serial No. Capacity   Type (enc/disk)
---------------------------------------------------------------------------------- 
1.1  0    HITACHI HUS72604CLAR4000 N9C0     K4HM1X7B   3.63 TiB   SAS 
1.2  1    HITACHI HUS72604CLAR4000 N9C0     K4HLLUBB   3.63 TiB   SAS 
1.3  2    HITACHI HUS72604CLAR4000 N9C0     K4HL7LHB   3.63 TiB   SAS 
1.4  3    HITACHI HUS72604CLAR4000 N9C0     K4HM49SB   3.63 TiB   SAS 
1.5  4    HITACHI HUSMR148_CLAR800 C342     07W87G3A   745.22 GiB SAS-SSD 
1.6  5    HITACHI HUSMR148_CLAR800 C342     07WV9L9A   745.22 GiB SAS-SSD 
1.7  6    HITACHI HUSMR148_CLAR800 C342     07VJAPMA   745.22 GiB SAS-SSD 
1.8  7    HITACHI HUSMR148_CLAR800 C342     07VL2RKA   745.22 GiB SAS-SSD 
1.9  8    HITACHI HUSMR148_CLAR800 C342     07WV98WA   745.22 GiB SAS-SSD 
2.1  A0   HITACHI HUS72604CLAR4000 N9C0     K3G37TXB   3.63 TiB   SAS 
...
---------------------------------------------------------------------------------- 

In this example, there are only 5 SAS-SSD's available which have already been added to Cache Tier (5 x 745.22 = 3.6 TiB).

This confirms this mismatch. 

The fix is to add additional disks to the cachie tier.
(In the given example, an additional three disks must be added to the Cache Tier.)

Refer to the DDOS administration guide for the procedure to add disks to Cache tier.