ZFS Component Naming Requirements
Each ZFS component must be named according to the following rules:
Empty components are not allowed.
 
Each component can only contain alphanumeric characters in addition to the following four special characters:
Underscore (_)
 
Hyphen (-)
 
Colon (:)
 
Period (.)
 
Pool names must begin with a letter, except for the following restrictions:
The beginning sequence c[0-9] is not allowed
 
The name log is reserved
 
A name that begins with mirror, raidz, or spare is not allowed because these name are reserved.
In addition, pool names must not contain a percent sign (%)
 
Dataset names must begin with an alphanumeric character. Dataset names must not contain a percent sign (%).