This topic describes performance considerations for users of optical media libraries.
Several factors can affect the optical performance of both LAN-attached and directly-attached optical media libraries. This topic explains how these factors can influence optical performance.
Volume mounting and dismounting are important factors that affect optical performance. It takes approximately 8 to 15 seconds to remove a volume, store it in a slot, retrieve a new volume, and mount it. If you can minimize the number of volume mounts and dismounts that your application requires, optical performance will improve.
Performance can be severely affected by drive contention. The following conditions increase drive contention and should be avoided:
Performance can be affected by having too few directories with too many files. Directories group related information to provide a means of quicker access. Typically, you get better performance from more directories with fewer files. Although there is no enforced limit on how many files there can be in a directory, you probably should not have more than 6000 for performance reasons.
The size of a file has a direct effect on the amount of time it takes to read, write, or copy the file. In general, the larger the file, the longer the operation can be expected to take.
Specifying *NO for the Rebuild Directory Index can improve the performance of Add Optical Cartridge (ADDOPTCTG) by deferring the build of the optical directory index until a later time.
