A magnetic media library drive includes a first disk medium fixed to a spindle, a first read-write transducer configured to operate on the first disk, a second read-write transducer configured to operate on a surface of a single removable second disk medium installed over the first disk, and electronic controller circuitry configured to cause: while the first transducer is servo-positioning from a master servo pattern from the first disk, the second transducer servo-writes a product servo pattern, based on the master servo pattern, to the surface of the second disk. The removable second disk can be removed, turned over, and secured to the spindle, whereby the self-servo writing procedure can be performed on the other side of the second disk based on the master servo pattern on the first disk.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A protruding peak height Spk specified in ISO 25178 on a surface of the magnetic layer is 1.5 nm or more and 3.0 nm or less, and standard deviation of the Spk in a width direction of the surface of the magnetic layer is 0.5 nm or less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. Sci obtained by measuring a surface of the magnetic layer with an atomic force microscope and by Equation A is 1.40 or more and 1.60 or less, and standard deviation of the Sci in a width direction of the surface of the magnetic layer is 0.05 or less. In Equation A, Sq is a root-mean-square height Sq specified in ISO 25178, Vv(h.sub.0.05)-Vv(h.sub.0.8) is a void volume in a region where a load area ratio in a bearing curve is 5% or more and 80% or less, and A is a measurement region area. $\begin{array}{cc}\mathrm{Sci}=\left(\frac{\mathrm{Vv}\left(h_{0.05}\right)-\mathrm{Vv}\left(h_{0.8}\right)}{A}\right)/\mathrm{Sq}& \mathrm{Equation}A\end{array}$