Re: Optical disk as raw disk?

Cynthia Leong (cynthia@hpsgcip1.sgp.hp.com) wrote: : Hi netters, : I'm planning to use the Optical Disk as raw disk for my Online engine. : The informix tech support personnel told me that as long as my system : support it, I can use it in place of the scsi hardisk. : Performance is not an issue because the optical disk acts as a online : archive store.I've the HP Optical Disk Library System Model 20 which : is a autochanger that gives me a capacity of 20GB. : Has anyone experienced setting up this library system? : I have some query concerning the setup .... : - is the creation of the device file the same as the scsi hardisk? : ie mknod , chown and grp to informix, chmod 660 etc : The Library system has two optical drive with addr 4 & 5. These : drive's addr is internal, I guess. Since the Library is a scsi : device and for the host system to communicate with it is through : its scsi addr, how can the host specifically talk to each drive? I've used the optical autochangers on HP 9000/8xx HP-UX boxes. The device files created refer to the platter in a particular slot of the autochanger. When the device file in /dev is "opened" HP-UX automatically mounts the platter in an available drive. Any application can perform I/O to a platter using standard read, write, open, close C functions. : - Can I partition the optical disk like scsi hardisk? : ie have several optical disks as one dbspace and on. : (I have slots for 32 pieces of optical disk) Yes the optical disks can be partitioned. When the autochanger is attached to an HP box the system automatically configures device nodes for all possible partitions for each possible optical disk. : Thanks for your help in advance. : Best regards, : Cynthia Leong : Hewlett-Packard, Singapore