With rewinding you mean: forward skipping? AFAIK this is prevented by the hardware and not overrable by software. Investigating the recoverability of overwritten data on tapes in the past, we ran into a company that had modified the 3490 microcode to read data that existed after the tapemark at the end of the overwriting data.
Kees. "J R" <jayare...@hotmail.com> wrote in message news:<bay145-w16b10a3a818b67b71a41da3...@phx.gbl>... > Rather than IOS, the channel should do the checking. For DASD, the SetFileMask command is used to prevent seeking outside of the dataset's extents. Don't remember if there's anything similar to prevent rewinding over tape marks. > > > > Date: Wed, 3 Oct 2012 09:15:50 -0500 > > From: john.mck...@healthmarkets.com > > Subject: Re: How to get a tape's DSCB > > To: IBM-MAIN@LISTSERV.UA.EDU > > > > It would be very difficult and have a lot of overhead to have IOS (not iOS) check every CCW chain for "suspect" CCWs. It is given as one of the reasons why RACF does not implement PDS member security. It's too easy to update a PDS member via TTR without any member name anywhere in sight. > > > > -- > > John McKown > > Systems Engineer IV > > IT > > > > Administrative Services Group > > > > HealthMarkets(r) > > > > 9151 Boulevard 26 * N. Richland Hills * TX 76010 > > (817) 255-3225 phone * > > john.mck...@healthmarkets.com * www.HealthMarkets.com > > > > Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM > > > > > > > -----Original Message----- > > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > > > On Behalf Of Paul Gilmartin > > > Sent: Wednesday, October 03, 2012 9:09 AM > > > To: IBM-MAIN@LISTSERV.UA.EDU > > > Subject: Re: How to get a tape's DSCB > > > > > > On Wed, 3 Oct 2012 07:55:44 -0500, McKown, John wrote: > > > > > > >And, just to be complete, you are assuming that your customers will be > > > using IBM standard tape labels. Granted, who doesn't? But it is an > > > assumption. Also, remember that in many shops, use of BLP to read the > > > tape labels can be protected via the tape management system, or even > > > with RACF now-a-days. Does not apply if you use EXCP to REW the tape, > > > of course. > > > > > > > Inconsistency. Either the REW CCW or EXCP itself should be likewise > > > RACF protected or protected by the tape management system. The > > > unprivileged user should have no opportunity to overwrite labels of > > > library tapes. > > > > > > I suppose a virtual tape might have a virtual label, and any attempt > > > to invalidate the label should fail or be ineffective. > > > > > > -- gil > > > > > > ---------------------------------------------------------------------- > > > For IBM-MAIN subscribe / signoff / archive access instructions, > > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
