User`s manual

Appendix B: Troubleshooting
104 AXIS StorPoint CD Token Ring - User’s Manual
Low Transfer Rates when Using Disc Changers
Disc changer flutter can occur if a user requests access to a disc when another
user is already reading data from another disc. The changer may then attempt to
service both requests by repeatedly changing between the two discs and
transferring a small amount of data each time. Because of the relatively long time
needed to change discs, the data transfer rate to both users will become
unacceptably low.
The JukeBox Lock Time parameter in the StorPoint CD configuration file
specifies how long a user has exclusive access to a disc during a data read
operation. This is to prevent disc change flutter in order to optimize access speed
when many users are accessing different discs in the same changer.
The JukeBox Lock Time parameter will ensure that when there are
simultaneous requests for access to different discs, a sizable block of data is
transferred to each user before the access is changed.
• If the JukeBox Lock Time parameter is set too low, the data transfer rate
will be unacceptably low.
• If the JukeBox Lock Time parameter is set too high, the disc drive will time-
out on a second user’s request before the first user’s access is completed. This
will result in users receiving a ‘
CD-ROM not available’ notice.
The default setting is 0 seconds which disables this function.