> -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[EMAIL PROTECTED] On Behalf Of Crispin Hugo > Sent: Friday, December 29, 2006 12:27 PM > To: IBM-MAIN@BAMA.UA.EDU > Subject: Re: Remote Tape drives > > > Cheers John, > I thought channel extenders had a finite distance , like > about 250k. I think > we are looking for something which would be IP based > > > Crispin Hugo > Systems Programmer, Macro 4
Hum, I think that you are correct. But that is all that I have heard of. The problem, as best as I can see it, is the slowness of the response from the tape due to the extreme slowness of the speed of light. <gring> Now, I know of a possible way to do it, but it would be VERY indirect and not "real time". Funsoft (http://www.funsoft.com), the makers of FlexES, have a system called the FLEXCUB. This is based on FlexES, sort of. What it does is make an Escon connected control unit. On the "back end" it can use the device emulation software from FlexES to control SCSI tape drives, emulated tape drives (AWS or FakeTape(tm) formatted volumes which "look like" tapes to the z/OS system) and disk volumes. What would be possible, but a real PAIN, would be to connect such a thing to your zSeries locally. Have the z/OS (or z/VSE or z/VM or z/Linux) write their data to an FakeTape(tm) volume which is on the local FlexCUB system. Have this FlexCUB system, which runs Linux, export the filesystem containing the FakeTape(tm) volumes using NFS or some other such software. Now, on the far end, have another PC running Linux with a SCSI attached tape drive import that filesystem. You'd likely need to VPN the two systems together over the Internet or a dedicated IP line (your choice). On the remote PC, have a daemon (or cron scheduled task) which can copy the FakeTape(tm) to an actual physical tape. There is a utility to do this from Funsoft. This would assume that the FakeTape(tm) on the FLEXCUB system would always be considered the authoritative source for the data on the particular volume. Instead of NFS, it might be possible to use some "file transfer" function such as ftp, scp, sftp, etc., to copy the data from the FLEXCUB system to the remote PC. Or, heaven forfend, encrypt it and email it <GRIN>. If you need to send the otherway, then just reverse the direction of the copy (I think). The main problem that I can see with this is how to know that the z/OS system has completed writing all the information to the tape so that it can be known that it is ready to be written to the physical tape. I.e. how to know that the tape is "complete" in the case where it contains multiple datasets, perhaps created over the course of even days. I have not thought about this. Now, the FLEXCUB software knows when z/OS has issued a "rewind and dismount" CCW. Perhaps there is a "hook" on the PC side which could trigger a Linux function of some sort. I would suggest talking with Funsoft about this possibility. Another problem is how to reconcile the z/OS tape label with the physical tape label. I mean the one on the outside of the tape, the copying will replace the internal tape label. But if the internal doesn't match the external, "you have problems" <grin>. This might be handled by something on the remote end conversing with the operator to mount a particular tape volser, then doing VOL1 verification on the remote PC before doing the actual tape copying. I do not offer this as a good solution. But it is all that I can think of. And I'm a bit bored due to the "hands off" that we are in due to year end processing. I hope you, and all others, don't mind. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
