I am very new to unRAID.  I have just started my initial configuration of the server.  I have two 4TB drives and one 120 SSD for cache.  I was able to assign the drives to the array, and formatted them.  My question is will all of the drives be erased?  I just want to make sure that unRAID will format and delete the data on the drives as I want to make sure they are clean.

 

Also, is it normal to have Parity invalid warning during the initial set up?

Edited March 5, 20179 yr by Seryth

No.   Formatting a drive does not erase all of its contents.   Any drives you add to a parity-protected array will be zeroed before they're added (this preserves the fault-tolerance of the array by ensuring the new drives doesn't invalidate parity) ... but the initial drives don't matter, so they're not erased.

 

Assuming you assigned one of the drives as a parity drive, THAT drive will be completely rewritten during the initial parity sync => but the other drive will have most of its original content (although it will "look" empty due to the format operation).

 

If you pre-cleared the drives, they've already been completely erased, however => or you could unassign them; pre-clear them; and then re-assign them with a New Config if you want to be sure they're completely cleared of all data.

 

13 minutes ago, Seryth said:

as I want to make sure they are clean.

 

Just to be clear -- if all you want is to be sure the file system is "clean", formatting is all you need to do.   That is essentially a "clean" system.   But if your concern is the old data on the drives, and if it COULD be accessed with appropriate data recovery software; then as I noted above, formatting does NOT clear all of that data.