Even though virtual tapes are essentially tape images on DASD, if a virtual tape dataset is allocated to a job or user, another dataset on the same virtual tape volume cannot be mounted elsewhere for use by another job or user. However, many virtual tape systems allow the size of each tape to be the size of the dataset being written to tape. Unless you're constrained by the number of tape volumes, why not put each dataset on its own tape? There is no wasted space, as there would be on a physical tape. Recycles then become unnecessary.
-----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Gibney, Dave Sent: Wednesday, March 13, 2024 5:09 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: What happens in HSM when I change a Management Class CAUTION: This email originated from outside of the Texas Comptroller's email system. DO NOT click links or open attachments unless you expect them from the sender and know the content is safe. With the relatively fast response of virtual tape, the recycle threshold can be set fairly high. I recycled daily. Assuming sufficient number of drives, it won't interfere with recall unless coincidentally actively recycling the dataset requested by the recall. > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of Paul Feller > Sent: Wednesday, March 13, 2024 2:56 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: What happens in HSM when I change a Management Class > > [EXTERNAL EMAIL] > > Gadi, Mike has a good point. Doing HSM tape recycles could help free > up any tapes with a low number of datasets on them. This is true for > migration tapes and backup tapes. Be warned that if you don't do tape > recycles on a scheduled basis the process could possibly run for a > long time. As an example, I think that could then impact HSM process > of recalls from tape. I believe the place I last worked at did tape recycles > every day. > > Also, I should have mentioned the information I pasted in my earlier > reply came from the "DFSMSdfp Storage Administration" manual for z/OS > 2.5. It can be found in "Chapter 8. Defining management classes". > > > Paul > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of Mike Schwab > Sent: Wednesday, March 13, 2024 1:30 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: What happens in HSM when I change a Management Class > > You should be recycling tapes with a low percent of active datasets. > This copies the remaining active datasets to a new tape then marking > this on as inactive. You can manually issue a recycle command against > a specific volume. > > On Wed, Mar 13, 2024 at 10:56 AM Gadi Ben-Avi <gad...@malam.com> > wrote: > > > > Hi Paul, > > Thanks for your detailed explanation. > > > > I would like to delete extra copies of backups, backups that have > > been on > HSM for more than a specified number of days, and as a result of that, > tapes that become empty will be deleted. > > > > The end result would be that every backed-up dataset that still > > exists could > have more than one backup, and datasets that do not exist anymore > would have only one backup. > > > > Gadi > > ________________________________ > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on > > behalf of Paul Feller <000005aa34d46684-dmarc- > requ...@listserv.ua.edu> > > Sent: Wednesday, March 13, 2024 16:09 > > To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU> > > Subject: Re: What happens in HSM when I change a Management Class > > > > [You don't often get email from > > 000005aa34d46684-dmarc-requ...@listserv.ua.edu. Learn why this is > > important at > > > https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld > %2F&data=05%7C02%7Cmichael.watkins%40CPA.TEXAS.GOV%7Cff65a2908dfe4f9fd > 94b08dc43aa4a31%7C2055feba299d4d0daa5a73b8b42fef08%7C0%7C0%7C638459645 > 889907153%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIi > LCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=qPR9LRq6TQnwML%2FpiE > TibumyZj%2BmeN5b68CcpzTYKgU%3D&reserved=0 > > > efense.com%2Fv3%2F__https%3A%2F%2Faka.ms%2FLearnAboutSenderIden > tificat > > ion__%3B!!JmPEgBY0HMszNaDT!r6UGjtMncSAT8VIJBN7GBgbaSWinibhN- > 31YdPqywAj > > 7VEo49ten-ZD68xvnm5B2SJnH0- > XRSX7NjMjKjetkygWrQLY1f7Lg%24&data=05%7C02% > > > 7CGIBNEY%40WSU.EDU%7C49b83bc6d619488994da08dc43a87355%7Cb5 > 2be471f7f147 > > > b4a8790c799bb53db5%7C0%7C0%7C638459637979687136%7CUnknown > %7CTWFpbGZsb3 > > > d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0 > %3D%7 > > > C0%7C%7C%7C&sdata=fx4o6v0XTZNQ79rXpyzyI6vHU8MBgknw4bNfjJ8ctU > Q%3D&reser > > ved=0 ] > > > > Gadi, I have to ask. Are trying to delete backups of individual > > datasets or the actual tapes created during dataset backup processing? > > > > If you are trying to manage the actual backups of individual > > datasets, have you looked at the different management classes used for the > > datasets? > > > > The following fields in the management class affect backups taken > > for an individual dataset. > > > > Retain Days Only Backup Ver: > > Indicates how many days to keep the most recent backup version of a > > deleted data set, starting from the day DFSMShsm detects it has been > > deleted. This attribute applies only when a data set no longer > > exists on primary (level 0) or migrated (levels 1 and 2) storage. > > The default is 60. This field does not apply to objects. Backup > > copies of objects are not retained when the original object is deleted. > > > > Retain Days Extra Backup Vers: > > Indicates how many days to keep backup versions other than the most > > recent one, starting from the day backups were created. It applies > > only when more than one backup version exists, and when a data set > > has low activity. This attribute applies whether the data set has > > been deleted or not. The default is 30. The number of extra versions > > is the number of backup versions minus one. If you specify 1 for > > Number of Backup Vers, there are no extra versions. For example, if > > you specify > > 3 for Number of Backup Vers (Data Set Deleted), the number of "extra" > > versions for deleted data sets is 2. These 2 versions are managed > > according to the Retain Days Extra Backup Vers attribute. Any other > > versions that may have existed when the data set was deleted will be > > deleted > the next time EXPIREBV is processed. > > > > Number of Backup Vers: > > Specifies the maximum number of backup versions to retain for a data set. > > The default is 2 if the data set still exists and 1 if it has been deleted. > > Creating a new backup version when the number of backup versions > > already equals the value specified for the appropriate Number of > > Backup Vers attribute (Data Set Exists) causes the oldest version of > > the appropriate type to be deleted. > > The number of backup versions is used to determine whether OAM > > should write one or two backup copies of the objects, when you > > activate the SECONDBACKUPGROUP function for objects using SETOSMC in > > the > CBROAMxx > > member of PARMLIB. If the number of backup versions is greater than > > 1 and AUTO BACKUP is Y, OAM will create two backup copies. When the > > original object is expired or deleted, all backup copies are also deleted. > > > > > > > > Paul > > > > -----Original Message----- > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > > Behalf Of Gadi Ben-Avi > > Sent: Wednesday, March 13, 2024 6:54 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: What happens in HSM when I change a Management Class > > > > Thanks > > > > -----Original Message----- > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > > Behalf Of Mark Jacobs > > Sent: יום ד 13 מרץ 2024 13:43 > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: What happens in HSM when I change a Management Class > > > > [You don't often get email from > > 00000224d287a4b1-dmarc-requ...@listserv.ua.edu. Learn why this is > > important at > > > https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld > %2F&data=05%7C02%7Cmichael.watkins%40CPA.TEXAS.GOV%7Cff65a2908dfe4f9fd > 94b08dc43aa4a31%7C2055feba299d4d0daa5a73b8b42fef08%7C0%7C0%7C638459645 > 890064341%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIi > LCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=laSz9vVYfC9Rxkjv0WzY > nSC94HAmoZ%2F0zTvGMEL1j9o%3D&reserved=0 > > > efense.com%2Fv3%2F__https%3A%2F%2Faka.ms%2FLearnAboutSenderIden > tificat > > ion__%3B!!JmPEgBY0HMszNaDT!r6UGjtMncSAT8VIJBN7GBgbaSWinibhN- > 31YdPqywAj > > 7VEo49ten-ZD68xvnm5B2SJnH0- > XRSX7NjMjKjetkygWrQLY1f7Lg%24&data=05%7C02% > > > 7CGIBNEY%40WSU.EDU%7C49b83bc6d619488994da08dc43a87355%7Cb5 > 2be471f7f147 > > > b4a8790c799bb53db5%7C0%7C0%7C638459637979696097%7CUnknown > %7CTWFpbGZsb3 > > > d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0 > %3D%7 > > > C0%7C%7C%7C&sdata=9PWTmfmshIXvN1Mxv1gOAeWIxmTxfEY6GwNsmev > vZfI%3D&reser > > ved=0 ] > > > > I believe it'll take affect during your secondary space management cycle. > > > > Mark Jacobs > > > > Sent from ProtonMail, Swiss-based encrypted email. > > > > GPG Public Key - > > > https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Furld > %2F&data=05%7C02%7Cmichael.watkins%40CPA.TEXAS.GOV%7Cff65a2908dfe4f9fd > 94b08dc43aa4a31%7C2055feba299d4d0daa5a73b8b42fef08%7C0%7C0%7C638459645 > 890070800%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIi > LCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=Kcu1tTpSbAuBV1790Pfl > MolN%2FEXBUkR8SknlJO45szE%3D&reserved=0 > efense.com%2Fv3%2F__https%3A%2F%2Feur04.safelinks.protection.outloo > k.com%2F%3Furl%3Dhttps*3A*2F*2Fapi__%3BJSUl!!JmPEgBY0HMszNaDT!r > 6UGjtMncSAT8VIJBN7GBgbaSWinibhN-31YdPqywAj7VEo49ten- > ZD68xvnm5B2SJnH0- > XRSX7NjMjKjetkygWrQAhSCQb7%24&data=05%7C02%7CGIBNEY%40WSU.E > DU%7C49b83bc6d619488994da08dc43a87355%7Cb52be471f7f147b4a87 > 90c799bb53db5%7C0%7C0%7C638459637979702807%7CUnknown%7CT > WFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiL > CJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=LBEXSoLGSMIcM1R6MMm4KiM > ig5q0tjdcFOwKM4Hcbms%3D&reserved=0 . > > > protonmail.ch%2Fpks%2Flookup%3Fop%3Dget%26search%3Dmarkjacobs% > 40proton > > > mail.com&data=05%7C02%7CGADI_B%40MALAM.COM%7C8464f7a004374 > 2165f4308dc4 > > > 36740ff%7C2669957b2b9e4ff0859535b303d5fcec%7C0%7C0%7C6384593 > 5796717343 > > > 4%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz > IiLCJBTiI6 > > > Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=nQjPuHbX%2FNSLUd > %2F5ToERFZ2U > > > epUpgz35HZWMAQRq6i4%3D&reserved=0<https://gcc02.safelinks.protection.o > utlook.com/?url=https%3A%2F%2Fnam12.safelinks.protecti%2F&data=05%7C02 > %7Cmichael.watkins%40CPA.TEXAS.GOV%7Cff65a2908dfe4f9fd94b08dc43aa4a31% > 7C2055feba299d4d0daa5a73b8b42fef08%7C0%7C0%7C638459645890075117%7CUnkn > own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwi > LCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=Yp0KdKhe2sS2hRB98XdC2vu9lvguOvx7CHxU > sSASrhk%3D&reserved=0 > on.o > > > utlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2 > F%2Fap > > > i.protonmail.ch%2Fpks%2Flookup__%3B!!JmPEgBY0HMszNaDT!r6UGjtMncS > AT8VIJ > > BN7GBgbaSWinibhN-31YdPqywAj7VEo49ten-ZD68xvnm5B2SJnH0- > XRSX7NjMjKjetkyg > > > WrQLb3SqqI%24&data=05%7C02%7CGIBNEY%40WSU.EDU%7C49b83bc6d6 > 19488994da08 > > > dc43a87355%7Cb52be471f7f147b4a8790c799bb53db5%7C0%7C0%7C63 > 845963797970 > > > 7778%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2l > uMzIiLCJBT > > > iI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=CanW3y81p%2Bb > ShNbs5vfXM%2 > > FnHZjYd3OLm4SyOUipkYVA%3D&reserved=0 > > ?op=get&search=markjac...@protonmail.com> > > > > > > On Wednesday, March 13th, 2024 at 6:46 AM, Gadi Ben-Avi > > <gad...@malam.com> > > wrote: > > > > > Hi > > > when reviewing our HSM configuration we found that the management > > > class > > used for all SMS backups says: > > > > > > Expire after Days Non-usage . . NOLIMIT (1 to 93000 or NOLIMIT) > > > Expire after Date/Days . . . . . NOLIMIT (0 to 93000, yyyy/mm/dd > > > or > > > NOLIMIT) > > > > > > Retention Limit . . . . . . . . . NOLIMIT (0 to 93000 or NOLIMIT) > > > > > > As I understand it, this means that backups will remain forever. > > > > > > If I change the values, will HSM start deleting backups? > > > Will it happen immediately, during nightly processing or do I have > > > to tell > > HSM to do it? > > > > > > Gadi > > > > > > ------------------------------------------------------------------ > > > -- > > > -- 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 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 > > > > -- > Mike A Schwab, Springfield IL USA > Where do Forest Rangers go to get away from it all? > > ---------------------------------------------------------------------- > 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 IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
