DataDomain: DD3300 unknown disk with no alerts.

           

   Article Number:     532806                                   Article Version: 2     Article Type:    Break Fix 
   

 


Product:

 

Data Domain,Data Domain Deduplication Storage Systems,DD3300 Appliance

 

Issue:

 

 

An unknown disk or multiple unknown disks present at the DD3300 model - with no alerts posted   
    When running the command "#disk show state" the DD3300 system presents unknown disk/s. For example:   
        

Disk Show State-----------------Dev   1  2  3  4  5  6  7  8  ---   ------------------------1-8   Y  Y  U  U  .  .  .  .  ---   ------------------------ Legend   State            Count------   --------------   -----.        In Use Device    4    U        Unknown Device   2    Y        System Device    2    ------   --------------   -----Total 0 disks and 8 devs    
                                                             

 

 

Cause:

 

 

DD3300 appliances have some disks reserved for the Cloud Tier. If the Cloud Tier is not activated the disk will be showed as "unknown".   
   
    The 1TB disk reserved for Cloud Tier can not be added to the Active Tier:   
    --> See KB:522643 : Issues configuring DD3300 related with the device reserved for cloud tier   
   
    The number or devices reserved depends on the DD3300 configuration. Please see the image below:   
    User-added image   
    Source: DD3300 Guide page 18 https://support.emc.com/docu87489_Data-Domain-DD3300-Hardware-Overview-and-Installation-Guide.pdf?language=en_US   
     
                                                           

 

 

Resolution:

 

 

The 'unknown' disk device is designated for use in the Cloud Tier.   
    As Cloud Tier is disabled the disk is showed as unknown disk.   
    The system is working as designed.