Disk scheduling using a customized discrete firefly algorithm

Figures & data

Table 1. Distance between two fireflies $i$ and $j$

Firefly $i$	140	13	120	79	60	15	500	11	90	10	16	300	2
Firefly $j$	140	13	120	15	500	79	60	11	90	10	16	300	2

Figure 1. Illustration of edge-based movement scheme.

Figure 2. Flow chart of the working scheme.

Table 2. Disk parameters pertaining to the disk model of Fujitsu M2361A

Cylinders per disk	842
Data transfer rate (MB/sec)	2.458
Seek time function (ms)	$\left\{\begin{array}{cc}4.6+0.87\times \surd (D_{j,i})\hfill & \text{if}{D}_{j,i}\le 239\hfill \\ 18+(D_{j,i}-239)\times 0.028\hfill & \text{if}{D}_{j,i}>239\hfill \end{array}\right)$
Rotational speed (RPM)	3,600 + 2%

Figure 3. Comparison of total seek time for the scheduling algorithms at a queue size of 15.

Figure 4. Performance for different instances disk sequences at given queue size.

Figure 5. The variation of total seek time (fitness) with the proceeding generations.

Figure 6. Total seek time vs. firefly population for different lengths.