Cleared vs. Unformatted partition in GParted

Question

I am running a database-like application that writes and reads data directly to and from a raw block device. I would like to create a new partition for this purpose, and I am using GParted. I've successfully shrank my regular Linux partition, and I can now see the free space listed as “unallocated“. Gparted allows you to choose to format this space to be “unformatted“ or “cleared“. I don't understand their difference.

In the GParted manual here, is says this:

• cleared can be used to clear any existing file system signatures and ensure that the partition is recognised as empty.
• unformatted can be used to just create a partition without writing a file system.

I couldn't find any elaboration on their difference. Can someone explain it? Also, is there any impact on the reliability of the partition, or on performance when writing and reading from it? Is one of them better-suited for my purpose? Are there any implications to just leaving the partition “unallocated“ as it currently is? Thanks!

Answer 1

These two options are unfortunately listed along with the others that act in a different manner. The other options are all filesystem formats, where the new partition is created with the selected format. These two options of interest are essentially the two null options.

• If one leaves a partition "unformatted" then no attempt to write filesystem data structures to it is made at all. But it might have them already, by accident or by design.
• If one "clears" a partition, then the various signatures in well-known places that operating systems use to detect filesystem types are wiped.

So, rather ironically, clearing a partition will give one the guarantee of it being unformatted as a result, whereas an unformatted partition may remain formatted as before.