Re: Optical disk as raw disk?

In <sharpeCE3qDx.4v7@netcom.com> sharpe@netcom.com (David W. Sharpe) writes: >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. But OnLine holds all its chunks open all the time, doesn't it? How did you get round that? >: - 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 graeme -- Disclaimer: The author's opinions are his own, and not necessarily those of Pyramid Technology Ltd. or Pyramid Technology Inc. --------------------------------------------------------------------------- -m------- Graeme Sargent Voice: +44 (0)252 373035 ---mmm----- Senior Database Consultant Fax : +44 (0)252 373135 -----mmmmm--- Pyramid Technology Ltd. Telex: Tell who??? -------mmmmmmm- Farnborough, Hants GU14 7PL Email: graeme@pyra.co.uk --------------------------------------------------------------------------- We have the technology. The tricky bit is learning how to use it.