User`s manual

Appendix A: Troubleshooting
AXIS StorPoint CD User’s Manual 107
Problems when Accessing Disc Changers
The
JukeBoxLockTime
parameter in the StorPoint CD configuration
file specifies how long a user has exclusive access to a CD-ROM
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.
Disc changer flutter can occur if a user requests access to a CD-ROM
when another user is already reading data from another CD-ROM.
The changer may then attempt to service both requests by repeatedly
changing between the two CD-ROMs and transferring a small
amount of data each time. Because of the relatively long time needed
to change CD-ROMs, the data transfer rate to both users will become
unacceptably low.
The
JukeBoxLockTime
parameter will ensure that when there are
simultaneous requests for access to different CD-ROMs, a sizable
block of data is transferred to each user before the CD-ROM access is
changed.
•If the
JukeBoxLockTime
parameter is set too low, the data
transfer rate will be unacceptably low.
•If the
JukeBoxLockTime
is set too high, the CD-ROM 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.