Re: Backup: Twinning Tapes to Remote Tape Unit
Perhaps by measuring the amount of tape left on the spindle? A light, possibly laser, shining on a tangent to the spindle at a specified height could be detected only when the tape remaining is not thick enough to block the light. This would remove any dependence on stickers which are supposed to be x feet or x inches from the physical end of the tape. There are other possibilities. For example, compare the speed in RPM of the two spindles. When the take-up spindle is over half full, it moves at a slower RPM than the other in order to keep the same linear rate for the tape. This could be used to determine the EOT. I would hope that the use of stickers to denote EOT would have gone out way back in my career. We used stickers in pre-S/360 days and they were fraught with problems then. Have you ever had to clean the heads and capstans of a tape drive that had become fouled with a sticker that did not stay stuck? Regards, Richard Schuh -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Stracka, James (GTS) Sent: Friday, June 06, 2008 8:36 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Now that is interesting. How does that OS/390 utility know where the EOT reflector is located unless it spins the entire tape first? -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of McKown, John Sent: Friday, June 06, 2008 9:48 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/. By messaging with Merrill Lynch you consent to the foregoing.
Re: Backup: Twinning Tapes to Remote Tape Unit
On Monday, 06/09/2008 at 04:06 EDT, Schuh, Richard [EMAIL PROTECTED] wrote: I would hope that the use of stickers to denote EOT would have gone out way back in my career. Reflective stickers went away with the 3480. It introduced a servo track that the drive uses to know the position of the tape at all times. EOT is at a certain physical block number, x. Every time. Bigger tape? Then you have a bigger value for x. The tape may be skipping bad data blocks on the tape, but they are at known locations and EOT still occurs at x, so the effective length will be less than the physical length. This is why degaussing today's tape cartridges results in a useless tape: the servo track is destroyed in the process. If you look at the sense data for today's drives, you'll see that it contains tons of block counters AND a [fuzzy] tape length indication. Alan Altmark z/VM Development IBM Endicott
Re: Backup: Twinning Tapes to Remote Tape Unit
I just knew that you (IBM) had to have done something about those stickers. They were a PITA. Regards, Richard Schuh -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Alan Altmark Sent: Monday, June 09, 2008 3:09 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit On Monday, 06/09/2008 at 04:06 EDT, Schuh, Richard [EMAIL PROTECTED] wrote: I would hope that the use of stickers to denote EOT would have gone out way back in my career. Reflective stickers went away with the 3480. It introduced a servo track that the drive uses to know the position of the tape at all times. EOT is at a certain physical block number, x. Every time. Bigger tape? Then you have a bigger value for x. The tape may be skipping bad data blocks on the tape, but they are at known locations and EOT still occurs at x, so the effective length will be less than the physical length. This is why degaussing today's tape cartridges results in a useless tape: the servo track is destroyed in the process. If you look at the sense data for today's drives, you'll see that it contains tons of block counters AND a [fuzzy] tape length indication. Alan Altmark z/VM Development IBM Endicott
Re: Backup: Twinning Tapes to Remote Tape Unit
I think in the case of having to run 2 backups jobs I would run one backup job and then run a utility job to copy the 1st set of tapes to the remote set of tapes. Jim Dodds Systems Programmer Kentucky State University 400 East Main Street Frankfort, Ky 40601 502 597 6114 -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Llewellyn Sent: Thursday, June 05, 2008 4:13 PM To: IBMVM@LISTSERV.UARK.EDU Subject: VM:Backup: Twinning Tapes to Remote Tape Unit Greetings, We are ramping up our Technical Recovery Plan, and intend to use channel- extended tape units at a remote location when performing our regular full and incremental backups. We use CA's VM:BACKUP for file-level backups, and will be using VM:HiDRO to capture the system image. We're curious as to whether any other CA customers are using the synchronous tape twinning feature with one local tape unit and one remote. We've been cautioned by our network folks that the response time from the remote tape unit would be quite a limiting factor affecting the speed of a synchronous, twinned backup. Our other option is to simply run two backup jobs, one to the local drive and one to the remote, but that effectively doubles the hit of the backup jobs. Any anecdotes or insight would be most welcome! Mark Llewellyn VM Systems Support Visa, Inc.
Re: Backup: Twinning Tapes to Remote Tape Unit
Can't do that, unless you can guarantee that the tapes at the remote site are longer than the local copy (which would be unlikely). When the backup runs, writing to a given pair of tapes ends when the first one hits EOT. You would also need to a complete copy of the tapes, labels and all, because the tapes are chained together with user labels. If you couldn't do that, then the copy utility would have have to be smart enough to generate the user label records according to VM:Backup specs. Since the VMBACKUP catalog wouldn't know about these tapes, any restores would have to be done using VMBRITS or VMBSAR. Mark L. Wheeler IT Infrastructure, 3M Center B224-4N-20, St Paul MN 55144 Tel: (651) 733-4355, Fax: (651) 736-7689 mlwheeler at mmm.com -- I have this theory that if one person can go out of their way to show compassion then it will start a chain reaction of the same. People will never know how far a little kindness can go. Rachel Joy Scott Dodds, Jim [EMAIL PROTECTED] duTo Sent by: The IBM IBMVM@LISTSERV.UARK.EDU z/VM Operating cc System [EMAIL PROTECTED] Subject ARK.EDU Re: Backup: Twinning Tapes to Remote Tape Unit 06/06/2008 08:29 AM Please respond to The IBM z/VM Operating System [EMAIL PROTECTED] ARK.EDU I think in the case of having to run 2 backups jobs I would run one backup job and then run a utility job to copy the 1st set of tapes to the remote set of tapes. Jim Dodds Systems Programmer Kentucky State University 400 East Main Street Frankfort, Ky 40601 502 597 6114 -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Llewellyn Sent: Thursday, June 05, 2008 4:13 PM To: IBMVM@LISTSERV.UARK.EDU Subject: VM:Backup: Twinning Tapes to Remote Tape Unit Greetings, We are ramping up our Technical Recovery Plan, and intend to use channel- extended tape units at a remote location when performing our regular full and incremental backups. We use CA's VM:BACKUP for file-level backups, and will be using VM:HiDRO to capture the system image. We're curious as to whether any other CA customers are using the synchronous tape twinning feature with one local tape unit and one remote. We've been cautioned by our network folks that the response time from the remote tape unit would be quite a limiting factor affecting the speed of a synchronous, twinned backup. Our other option is to simply run two backup jobs, one to the local drive and one to the remote, but that effectively doubles the hit of the backup jobs. Any anecdotes or insight would be most welcome! Mark Llewellyn VM Systems Support Visa, Inc.
Re: Backup: Twinning Tapes to Remote Tape Unit
Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. Not that I'm aware of. Mark Wheeler
Re: Backup: Twinning Tapes to Remote Tape Unit
-Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Wheeler Sent: Friday, June 06, 2008 8:39 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Can't do that, unless you can guarantee that the tapes at the remote site are longer than the local copy (which would be unlikely). When the backup runs, writing to a given pair of tapes ends when the first one hits EOT. You would also need to a complete copy of the tapes, labels and all, because the tapes are chained together with user labels. If you couldn't do that, then the copy utility would have have to be smart enough to generate the user label records according to VM:Backup specs. Since the VMBACKUP catalog wouldn't know about these tapes, any restores would have to be done using VMBRITS or VMBSAR. Mark L. Wheeler Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. -- 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.
Re: Backup: Twinning Tapes to Remote Tape Unit
And after having run into the (barely) shorter-output-tape situation after a major, self-induced problem with VM:Backup here (accidentally scratching hundreds of tapes, but of those none from the same twin set), I opened an enhancement request (now called a DAR) with perhaps then Systems Center (been a long time) asking for such a capability It was never implemented. I don't recall any more if it was canned, or still sits there queued in DAR limbo. BTW, someone suggested in this thread the idea of making manual copies after the backup completes, but then only being able to restore them with VMBRITS and VMBSAR. Warning: VMBSAR does not support 3590+ tapes. VM:Backup will happily make physical backups to 3590 tapes, but there's no way to restore them without a running VMBACKUP svm, and access to the VM:Backup catalog containing the physical tape backups. A chicken-and-egg problem. Works for us, but you really need to think of all the aspects to make it work. HiDRO is the alternative which circumvents the lack of 3590 support in VMBSAR. Mike Walter Hewitt Associates Any opinions expressed herein are mine alone and do not necessarily represent the opinions or policies of Hewitt Associates. Mark Wheeler [EMAIL PROTECTED] Sent by: The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU 06/06/2008 08:50 AM Please respond to The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU To IBMVM@LISTSERV.UARK.EDU cc Subject Re: Backup: Twinning Tapes to Remote Tape Unit Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. Not that I'm aware of. Mark Wheeler The information contained in this e-mail and any accompanying documents may contain information that is confidential or otherwise protected from disclosure. If you are not the intended recipient of this message, or if this message has been addressed to you in error, please immediately alert the sender by reply e-mail and then delete this message, including any attachments. Any dissemination, distribution or other use of the contents of this message by anyone other than the intended recipient is strictly prohibited. All messages sent to and from this e-mail address may be monitored as permitted by applicable law and regulations to ensure compliance with our internal policies and to protect our business. E-mails are not secure and cannot be guaranteed to be error free as they can be intercepted, amended, lost or destroyed, or contain viruses. You are deemed to have accepted these risks if you communicate with us by e-mail.
Re: Backup: Twinning Tapes to Remote Tape Unit
That is a good point that I had not completely thought thru about the tape lengths. So forget about what I said. Jim Dodds Systems Programmer Kentucky State University 400 East Main Street Frankfort, Ky 40601 502 597 6114 -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Wheeler Sent: Friday, June 06, 2008 9:39 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Can't do that, unless you can guarantee that the tapes at the remote site are longer than the local copy (which would be unlikely). When the backup runs, writing to a given pair of tapes ends when the first one hits EOT. You would also need to a complete copy of the tapes, labels and all, because the tapes are chained together with user labels. If you couldn't do that, then the copy utility would have have to be smart enough to generate the user label records according to VM:Backup specs. Since the VMBACKUP catalog wouldn't know about these tapes, any restores would have to be done using VMBRITS or VMBSAR. Mark L. Wheeler IT Infrastructure, 3M Center B224-4N-20, St Paul MN 55144 Tel: (651) 733-4355, Fax: (651) 736-7689 mlwheeler at mmm.com -- I have this theory that if one person can go out of their way to show compassion then it will start a chain reaction of the same. People will never know how far a little kindness can go. Rachel Joy Scott Dodds, Jim [EMAIL PROTECTED] du To Sent by: The IBM IBMVM@LISTSERV.UARK.EDU z/VM Operating cc System [EMAIL PROTECTED] Subject ARK.EDU Re: Backup: Twinning Tapes to Remote Tape Unit 06/06/2008 08:29 AM Please respond to The IBM z/VM Operating System [EMAIL PROTECTED] ARK.EDU I think in the case of having to run 2 backups jobs I would run one backup job and then run a utility job to copy the 1st set of tapes to the remote set of tapes. Jim Dodds Systems Programmer Kentucky State University 400 East Main Street Frankfort, Ky 40601 502 597 6114 -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Llewellyn Sent: Thursday, June 05, 2008 4:13 PM To: IBMVM@LISTSERV.UARK.EDU Subject: VM:Backup: Twinning Tapes to Remote Tape Unit Greetings, We are ramping up our Technical Recovery Plan, and intend to use channel- extended tape units at a remote location when performing our regular full and incremental backups. We use CA's VM:BACKUP for file-level backups, and will be using VM:HiDRO to capture the system image. We're curious as to whether any other CA customers are using the synchronous tape twinning feature with one local tape unit and one remote. We've been cautioned by our network folks that the response time from the remote tape unit would be quite a limiting factor affecting the speed of a synchronous, twinned backup. Our other option is to simply run two backup jobs, one to the local drive and one to the remote, but that effectively doubles the hit of the backup jobs. Any anecdotes or insight would be most welcome! Mark Llewellyn VM Systems Support Visa, Inc.
Re: Backup: Twinning Tapes to Remote Tape Unit
Now that is interesting. How does that OS/390 utility know where the EOT reflector is located unless it spins the entire tape first? -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of McKown, John Sent: Friday, June 06, 2008 9:48 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/. By messaging with Merrill Lynch you consent to the foregoing.
Re: Backup: Twinning Tapes to Remote Tape Unit
-Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Stracka, James (GTS) Sent: Friday, June 06, 2008 10:36 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Now that is interesting. How does that OS/390 utility know where the EOT reflector is located unless it spins the entire tape first? Well, it doesn't really __know__. It does know the approprimate length of the tape from a sense command. The drive knows what type of tape medium is mounted on it. It then estimates how many blocks it should write. The 3490 and later drives will tell, via a sense command, the current block id (this accounts for compression on the drive). When the current block id is greater than the estimate, then the utility does an FEOV to force an end-of-volume switch. -- 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.
Re: Backup: Twinning Tapes to Remote Tape Unit
There is a round about way of doing this. Fran and I came up with it about 4 years ago. VMBACKUP can backup to DASD. With that, you need to specify the size of a tape file that will exist on disk. Then, you do, in my case, a twin backup specifying a disk file and tape. When the disk file is full, it will start a new disk and a new tape file. I do believe there is a triple option of running a backup against 3 output devices. So this may help with a twin. Anyway, if you are running twin backups from VMBACKUP both copies will be the same size as the smallest media. You shouldn't have a problem there. Tom Duerbusch THD Consulting Law of Cat Acceleration A cat will accelerate at a constant rate, until he gets good and ready to stop. Mark Wheeler [EMAIL PROTECTED] 6/6/2008 8:50 AM Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. Not that I'm aware of. Mark Wheeler
Re: Backup: Twinning Tapes to Remote Tape Unit
My enhancement request suggested to writing until EOV, then back up to the beginning of that VM:Backup domain, close the tape (with all the usual EOV, and cross-linked User Header and Trailer Labels), and re-write that domain on the fresh tape. It got more complex when a single domain would not fit on a single tape, but with newer tape technologies that may no longer be a significant problem. Food for fresh thoughts. Mike Walter Hewitt Associates Any opinions expressed herein are mine alone and do not necessarily represent the opinions or policies of Hewitt Associates. Stracka, James (GTS) [EMAIL PROTECTED] Sent by: The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU 06/06/2008 10:35 AM Please respond to The IBM z/VM Operating System IBMVM@LISTSERV.UARK.EDU To IBMVM@LISTSERV.UARK.EDU cc Subject Re: Backup: Twinning Tapes to Remote Tape Unit Now that is interesting. How does that OS/390 utility know where the EOT reflector is located unless it spins the entire tape first? -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of McKown, John Sent: Friday, June 06, 2008 9:48 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Curiousity question, because I don't know VM:Backup, is there a way to tell VM:Backup to only use n% of a tape? Our z/OS backup utility can be told to do this. If this is possible, then you could fill a tape up to, say, 80% and be fairly confident that the second tape would be long enough to hold that data. This message w/attachments (message) may be privileged, confidential or proprietary, and if you are not an intended recipient, please notify the sender, do not use or share it and delete it. Unless specifically indicated, this message is not an offer to sell or a solicitation of any investment products or other financial product or service, an official confirmation of any transaction, or an official statement of Merrill Lynch. Subject to applicable law, Merrill Lynch may monitor, review and retain e-communications (EC) traveling through its networks/systems. The laws of the country of each sender/recipient may impact the handling of EC, and EC may be archived, supervised and produced in countries other than the country in which you are located. This message cannot be guaranteed to be secure or error-free. This message is subject to terms available at the following link: http://www.ml.com/e-communications_terms/ . By messaging with Merrill Lynch you consent to the foregoing. The information contained in this e-mail and any accompanying documents may contain information that is confidential or otherwise protected from disclosure. If you are not the intended recipient of this message, or if this message has been addressed to you in error, please immediately alert the sender by reply e-mail and then delete this message, including any attachments. Any dissemination, distribution or other use of the contents of this message by anyone other than the intended recipient is strictly prohibited. All messages sent to and from this e-mail address may be monitored as permitted by applicable law and regulations to ensure compliance with our internal policies and to protect our business. E-mails are not secure and cannot be guaranteed to be error free as they can be intercepted, amended, lost or destroyed, or contain viruses. You are deemed to have accepted these risks if you communicate with us by e-mail.
Re: Backup: Twinning Tapes to Remote Tape Unit
Can't do that, unless you can guarantee that the tapes at the remote site are longer than the local copy (which would be unlikely). When the backup runs, writing to a given pair of tapes ends when the first one hits EOT. That's yet another complication for us if were to use twins. We use 9840 (STK high capacity) tapes for our local backups and 3490 (in a VTS) for our remote backups. We'd have to change our local backups to 3490 tapes, and we don't have enough silo slots to do that. A full backup for us is 6 9840 tapes, or 145 virtual tapes. I tested a small backup of 11 3390-3 volumes with twins. It took seven 3490E cartridges, and seven 9840 cartridges. Mark is right, both streams get a new tape when the first one hits EOT, even if they have vastly different capacities. Dennis Don't worry about biting off more than you can chew. Your mouth is bigger than you think. -- CVW-11 chaplain, Carrier
Re: Backup: Twinning Tapes to Remote Tape Unit
Copying tapes is fraught with enough potential issues (many illuminated here) that we are not going to consider it... -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Wheeler Sent: Friday, June 06, 2008 6:39 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Backup: Twinning Tapes to Remote Tape Unit Can't do that, unless you can guarantee that the tapes at the remote site are longer than the local copy (which would be unlikely). When the backup runs, writing to a given pair of tapes ends when the first one hits EOT. You would also need to a complete copy of the tapes, labels and all, because the tapes are chained together with user labels. If you couldn't do that, then the copy utility would have have to be smart enough to generate the user label records according to VM:Backup specs. Since the VMBACKUP catalog wouldn't know about these tapes, any restores would have to be done using VMBRITS or VMBSAR. Mark L. Wheeler IT Infrastructure, 3M Center B224-4N-20, St Paul MN 55144 Tel: (651) 733-4355, Fax: (651) 736-7689 mlwheeler at mmm.com -- I have this theory that if one person can go out of their way to show compassion then it will start a chain reaction of the same. People will never know how far a little kindness can go. Rachel Joy Scott Dodds, Jim [EMAIL PROTECTED] du To Sent by: The IBM IBMVM@LISTSERV.UARK.EDU z/VM Operating cc System [EMAIL PROTECTED] Subject ARK.EDU Re: Backup: Twinning Tapes to Remote Tape Unit 06/06/2008 08:29 AM Please respond to The IBM z/VM Operating System [EMAIL PROTECTED] ARK.EDU I think in the case of having to run 2 backups jobs I would run one backup job and then run a utility job to copy the 1st set of tapes to the remote set of tapes. Jim Dodds Systems Programmer Kentucky State University 400 East Main Street Frankfort, Ky 40601 502 597 6114 -Original Message- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Mark Llewellyn Sent: Thursday, June 05, 2008 4:13 PM To: IBMVM@LISTSERV.UARK.EDU Subject: VM:Backup: Twinning Tapes to Remote Tape Unit Greetings, We are ramping up our Technical Recovery Plan, and intend to use channel- extended tape units at a remote location when performing our regular full and incremental backups. We use CA's VM:BACKUP for file-level backups, and will be using VM:HiDRO to capture the system image. We're curious as to whether any other CA customers are using the synchronous tape twinning feature with one local tape unit and one remote. We've been cautioned by our network folks that the response time from the remote tape unit would be quite a limiting factor affecting the speed of a synchronous, twinned backup. Our other option is to simply run two backup jobs, one to the local drive and one to the remote, but that effectively doubles the hit of the backup jobs. Any anecdotes or insight would be most welcome! Mark Llewellyn VM Systems Support Visa, Inc.
