T420 - Dell Compatible - 600GB 15K RPM SAS 3.5" HD - Mfg # W347K ST3600057SS and SAS 2.5" on RAID-5 ARRAY

You can use it.

You don't have to have that exact part number ... Dell still has 3.5" 600GB 15K SAS drives available - it may just not be that same part number.

You might consider a different reseller - one with better knowledge, better stock, or a better supply network.

 I GOT New DELL sas  600 drive 2.5" with 3.5" adapter  - to assign it to  global hot spare on raid 5 array.

When I insert the drive in to T420 slot i see  "Foreign"  on the Physical Disks on Controller PERC H710 Adapter menu 

What does it mean ?

Incompatible Hard Drive? 

Dell OpenManag 8.2.0

FLASH1932 I found post that you explain 

FLASH1932 "Yes, you need to CLEAR the foreign configuration. Do this in OMSA, Storage, PERC, Information Configuration link, Foreign/Clear from dropdown menu of Available Tasks for the controller."  

I can see "Foreign configuraion operation" in  dropdown menu 

Inside I see IR Virtual Disk link

inside I see  my Physical Disk 0:1:7  hard drive but I don`t see Clear task for excute. only BLINK\UNBLINK 

where is the clean option

Lots of things can keep it from showing as foreign or not rebuilding automatically.

Did you shut down the server to replace the drive?

Foreign just means the configuration on the drive doesn't match the configuration on the controller, so you need to CLEAR that configuration. Clearing the foreign configuration is a CONTROLLER task, not a DISK task.

OMSA, Storage, PERC, Information Configuration link, Foreign/Clear from dropdown menu of Available Tasks for the controller.

I don`t want to replace disk , only to add hot spare disk for emergency. (making one spare hard drive ready)

I didn`t shutdown the server.

OPENMANAGE - >  PERC H710 Adapter (PCI Slot 6) - > Information Configuration link - > Controller Tasks (inside properties box) - > foreign configuration operations -> execute 

new page - > IR Virtual Disk link  (inside Virtual Disks box) - >  Physical Disk 0:1:7  - BLINK\UNBLINK task for execute task

what do i missing ?

**on the - IR Virtual Disk-   page I see import\recovery option 

After Full Shutdown the CLEAR button Appears  on that page !!! :-)