Re: [Veritas-bu] Media Tape Writes and Retentions
On Sun, Feb 22, 2009 at 11:00:08AM +1100, Dean wrote: > 4) When that happens how does the time assigned change? Will it keep the > initial time assigned or change to the Latest time assigned image? > > I'm not really sure, but I think the "time assigned" value stays the same. > It always indicates the time the first image was written to that tape, > regardless of whether that image has since expired or not. When a tape is expired by Netbackup, it returns the volume to the volume manager by removing the "assigned" time. Neither new nor returned scratch tapes will have one. The next time it is used, it will get a new "assigned" time. So the information in 'bpmedialist' is basically thrown away each time the volume expires. -- Darren ___ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
Re: [Veritas-bu] Media Tape Writes and Retentions
1) Will each week of writes have a separate 5 week retention? Yes 2) Can the tape be written to again (over week 1 space on tape) by week 6 or will something else happen? If the tape is not full, yes, it can still be appended to by backups that have the same retention. But it won't write over week 1, if week 2 data is after that on the tape. Remember, tapes are serial by their nature. You can't insert data on a tape, generally. 3) When the time is unassigned I am assuming that is all backup images expiring. Will the tape be written to as long as it is in a Library or drive and not write protected .. every time a segment of images expire on the tape? Hmm, not sure what you mean here. Once the tape is full, every image on the tape needs to have expired before the tape will be used for writing again. If an earlier image on the tape has expired, there is no way for NBU to insert a new backup image over the expired image, Tapes are "append only". 4) When that happens how does the time assigned change? Will it keep the initial time assigned or change to the Latest time assigned image? I'm not really sure, but I think the "time assigned" value stays the same. It always indicates the time the first image was written to that tape, regardless of whether that image has since expired or not. On Thu, Feb 19, 2009 at 4:03 AM, wrote: > I should clairfi this part > > now you have blankspace, week2image, week3i mage, week4image > > > > it is not really a blankspace – it is an expired image. (the info on the > tape does not get erased). > > You could still import the tape and get back week1image if needed. > > > -- > > *From:* Jackson, Todd [mailto:c-todd.jack...@invitrogen.com] > *Sent:* Wednesday, February 18, 2009 10:59 AM > *To:* Judy Hinchcliffe; veritas-bu@mailman.eng.auburn.edu > > *Subject:* RE: [Veritas-bu] Media Tape Writes and Retentions > > > > HI Judy > > > > Thank you for your reply > > > > Yes I was referring to IMAGES and not actual TAPE but was careless in my > general terminology. > > I have no plans on mixing retentions or leaving a media tape in the Library > after it has been assigned. > > We have some new policies for offsite retentions and I just wanted to throw > out a spare of the moment scenario to gather some information. > > > > Everything you sent was Extremely helpful and very informative and I thank > you for taking to time to > > explain. There were some things that I did not know that you have cleared > up. > > > > > > Thanks > > -T > > > > > -- > > *From:* judy_hinchcli...@administaff.com [mailto: > judy_hinchcli...@administaff.com] > *Sent:* Wednesday, February 18, 2009 11:43 AM > *To:* Jackson, Todd; veritas-bu@mailman.eng.auburn.edu > *Subject:* RE: [Veritas-bu] Media Tape Writes and Retentions > > > > 1) The IMAGE has the 5 week retention not the tape. > > a. Is if you write to the same tape 3 weeks in a row the tape will > not become scratch until the oldest images on the tape expires (week 3's > image date + 5 weeks) > > 2) no > > a. when writing to a tape it will only append to the end of the > tape, past the last written image to the tape > > b. so if you have week1image, week2image,week3image, week4image > > c. and ^ week1 expires > > d. now you have blankspace, week2image, week3i mage, week4image > > e. and you write to the same tape again you get > > f.blankspace, week2image, week3image, > week4image, week5image (tape is now full) (will not become scratch until > week5's image expires) > > 3) if the tape has no assigned time then it is a scratch, no valid > images on it > > a. if the tape is in the library and in a pool that your policy can > use or the scratch pool it can be written to. > > b. If you leave the tape in the library your backups will continue to > write to the tape until it is FULL > > c. If the tape becomes FULL meaning that it has written all the way > to the EOT it will NOT write to again until all images on the tape have > expired (see #2) > > d. If you do not allow different retention levels on the same tape – > say mixing of 5 week retention and 6 month retention, then it will choose a > different tape for the 6 month retention. > > 4) As the first image is written to the tape it gets an assigned > date. On the second day when it writes to the tape it will not change the > assigned date, but it will change the expiration date (as the expiration > date is based on when the last ima
Re: [Veritas-bu] Media Tape Writes and Retentions
I should clairfi this part now you have blankspace, week2image, week3i mage, week4image it is not really a blankspace - it is an expired image. (the info on the tape does not get erased). You could still import the tape and get back week1image if needed. From: Jackson, Todd [mailto:c-todd.jack...@invitrogen.com] Sent: Wednesday, February 18, 2009 10:59 AM To: Judy Hinchcliffe; veritas-bu@mailman.eng.auburn.edu Subject: RE: [Veritas-bu] Media Tape Writes and Retentions HI Judy Thank you for your reply Yes I was referring to IMAGES and not actual TAPE but was careless in my general terminology. I have no plans on mixing retentions or leaving a media tape in the Library after it has been assigned. We have some new policies for offsite retentions and I just wanted to throw out a spare of the moment scenario to gather some information. Everything you sent was Extremely helpful and very informative and I thank you for taking to time to explain. There were some things that I did not know that you have cleared up. Thanks -T From: judy_hinchcli...@administaff.com [mailto:judy_hinchcli...@administaff.com] Sent: Wednesday, February 18, 2009 11:43 AM To: Jackson, Todd; veritas-bu@mailman.eng.auburn.edu Subject: RE: [Veritas-bu] Media Tape Writes and Retentions 1) The IMAGE has the 5 week retention not the tape. a. Is if you write to the same tape 3 weeks in a row the tape will not become scratch until the oldest images on the tape expires (week 3's image date + 5 weeks) 2) no a. when writing to a tape it will only append to the end of the tape, past the last written image to the tape b. so if you have week1image, week2image,week3image, week4image c. and ^ week1 expires d. now you have blankspace, week2image, week3i mage, week4image e. and you write to the same tape again you get f.blankspace, week2image, week3image, week4image, week5image (tape is now full) (will not become scratch until week5's image expires) 3) if the tape has no assigned time then it is a scratch, no valid images on it a. if the tape is in the library and in a pool that your policy can use or the scratch pool it can be written to. b. If you leave the tape in the library your backups will continue to write to the tape until it is FULL c. If the tape becomes FULL meaning that it has written all the way to the EOT it will NOT write to again until all images on the tape have expired (see #2) d. If you do not allow different retention levels on the same tape - say mixing of 5 week retention and 6 month retention, then it will choose a different tape for the 6 month retention. 4) As the first image is written to the tape it gets an assigned date. On the second day when it writes to the tape it will not change the assigned date, but it will change the expiration date (as the expiration date is based on when the last image on the tape will expire and the tape becomes scratch.) In my production environment we remove the tapes from the library every morning and send them off site. So my assigned time on my tape represents when my backups were done, because I do NOT put more then one days backup on a tape ( what if the tape went bad and I could not read it, I could loose days of data. I do not mix retention periods on my tape because I could have just 1 gig of data on a tape with a 6 month retention and 400 gig of 2 week retention. That tape does not become scratch again until the 6 months have passed. From: veritas-bu-boun...@mailman.eng.auburn.edu [mailto:veritas-bu-boun...@mailman.eng.auburn.edu] On Behalf Of Jackson, Todd Sent: Wednesday, February 18, 2009 10:18 AM To: veritas-bu@mailman.eng.auburn.edu Subject: [Veritas-bu] Media Tape Writes and Retentions Hello All, I have a question concerning LTO tape writes that I need some clarity about. Scenario: If you have a Retention of 5 weeks for a policy and you write a job the first day which gives the Images 5 weeks until expiration. When you write to that tape again on week 2, week 3 ... etc. My question are 1) Will each week of writes have a separate 5 week retention? 2) Can the tape be written to again (over week 1 space on tape) by week 6 or will something else happen? 3) When the time is unassigned I am assuming that is all backup images expiring. Will the tape be written to as long as it is in a Library or drive and not write protected .. every time a segment of images expire on the tape? 4) When that happens how does the time assigned change? Will it keep the initial time assigned or change to the Latest time assigned image? LTO MEDIA TAPE USAGE | Week 1, Write job| Week 2, Write job | Week 3, write job | Wee
Re: [Veritas-bu] Media Tape Writes and Retentions
HI Judy Thank you for your reply Yes I was referring to IMAGES and not actual TAPE but was careless in my general terminology. I have no plans on mixing retentions or leaving a media tape in the Library after it has been assigned. We have some new policies for offsite retentions and I just wanted to throw out a spare of the moment scenario to gather some information. Everything you sent was Extremely helpful and very informative and I thank you for taking to time to explain. There were some things that I did not know that you have cleared up. Thanks -T From: judy_hinchcli...@administaff.com [mailto:judy_hinchcli...@administaff.com] Sent: Wednesday, February 18, 2009 11:43 AM To: Jackson, Todd; veritas-bu@mailman.eng.auburn.edu Subject: RE: [Veritas-bu] Media Tape Writes and Retentions 1) The IMAGE has the 5 week retention not the tape. a. Is if you write to the same tape 3 weeks in a row the tape will not become scratch until the oldest images on the tape expires (week 3's image date + 5 weeks) 2) no a. when writing to a tape it will only append to the end of the tape, past the last written image to the tape b. so if you have week1image, week2image,week3image, week4image c. and ^ week1 expires d. now you have blankspace, week2image, week3i mage, week4image e. and you write to the same tape again you get f. blankspace, week2image, week3image, week4image, week5image (tape is now full) (will not become scratch until week5's image expires) 3) if the tape has no assigned time then it is a scratch, no valid images on it a. if the tape is in the library and in a pool that your policy can use or the scratch pool it can be written to. b. If you leave the tape in the library your backups will continue to write to the tape until it is FULL c. If the tape becomes FULL meaning that it has written all the way to the EOT it will NOT write to again until all images on the tape have expired (see #2) d. If you do not allow different retention levels on the same tape - say mixing of 5 week retention and 6 month retention, then it will choose a different tape for the 6 month retention. 4) As the first image is written to the tape it gets an assigned date. On the second day when it writes to the tape it will not change the assigned date, but it will change the expiration date (as the expiration date is based on when the last image on the tape will expire and the tape becomes scratch.) In my production environment we remove the tapes from the library every morning and send them off site. So my assigned time on my tape represents when my backups were done, because I do NOT put more then one days backup on a tape ( what if the tape went bad and I could not read it, I could loose days of data. I do not mix retention periods on my tape because I could have just 1 gig of data on a tape with a 6 month retention and 400 gig of 2 week retention. That tape does not become scratch again until the 6 months have passed. From: veritas-bu-boun...@mailman.eng.auburn.edu [mailto:veritas-bu-boun...@mailman.eng.auburn.edu] On Behalf Of Jackson, Todd Sent: Wednesday, February 18, 2009 10:18 AM To: veritas-bu@mailman.eng.auburn.edu Subject: [Veritas-bu] Media Tape Writes and Retentions Hello All, I have a question concerning LTO tape writes that I need some clarity about. Scenario: If you have a Retention of 5 weeks for a policy and you write a job the first day which gives the Images 5 weeks until expiration. When you write to that tape again on week 2, week 3 ... etc. My question are 1) Will each week of writes have a separate 5 week retention? 2) Can the tape be written to again (over week 1 space on tape) by week 6 or will something else happen? 3) When the time is unassigned I am assuming that is all backup images expiring. Will the tape be written to as long as it is in a Library or drive and not write protected .. every time a segment of images expire on the tape? 4) When that happens how does the time assigned change? Will it keep the initial time assigned or change to the Latest time assigned image? LTO MEDIA TAPE USAGE | Week 1, Write job| Week 2, Write job | Week 3, write job | Week 4, write job|Week 5, write job Any other information is appreciated concerning how this works. Thanks -T ___ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
Re: [Veritas-bu] Media Tape Writes and Retentions
1) The IMAGE has the 5 week retention not the tape. a. Is if you write to the same tape 3 weeks in a row the tape will not become scratch until the oldest images on the tape expires (week 3's image date + 5 weeks) 2) no a. when writing to a tape it will only append to the end of the tape, past the last written image to the tape b. so if you have week1image, week2image,week3image, week4image c. and ^ week1 expires d. now you have blankspace, week2image, week3i mage, week4image e. and you write to the same tape again you get f.blankspace, week2image, week3image, week4image, week5image (tape is now full) (will not become scratch until week5's image expires) 3) if the tape has no assigned time then it is a scratch, no valid images on it a. if the tape is in the library and in a pool that your policy can use or the scratch pool it can be written to. b. If you leave the tape in the library your backups will continue to write to the tape until it is FULL c. If the tape becomes FULL meaning that it has written all the way to the EOT it will NOT write to again until all images on the tape have expired (see #2) d. If you do not allow different retention levels on the same tape - say mixing of 5 week retention and 6 month retention, then it will choose a different tape for the 6 month retention. 4) As the first image is written to the tape it gets an assigned date. On the second day when it writes to the tape it will not change the assigned date, but it will change the expiration date (as the expiration date is based on when the last image on the tape will expire and the tape becomes scratch.) In my production environment we remove the tapes from the library every morning and send them off site. So my assigned time on my tape represents when my backups were done, because I do NOT put more then one days backup on a tape ( what if the tape went bad and I could not read it, I could loose days of data. I do not mix retention periods on my tape because I could have just 1 gig of data on a tape with a 6 month retention and 400 gig of 2 week retention. That tape does not become scratch again until the 6 months have passed. From: veritas-bu-boun...@mailman.eng.auburn.edu [mailto:veritas-bu-boun...@mailman.eng.auburn.edu] On Behalf Of Jackson, Todd Sent: Wednesday, February 18, 2009 10:18 AM To: veritas-bu@mailman.eng.auburn.edu Subject: [Veritas-bu] Media Tape Writes and Retentions Hello All, I have a question concerning LTO tape writes that I need some clarity about. Scenario: If you have a Retention of 5 weeks for a policy and you write a job the first day which gives the Images 5 weeks until expiration. When you write to that tape again on week 2, week 3 ... etc. My question are 1) Will each week of writes have a separate 5 week retention? 2) Can the tape be written to again (over week 1 space on tape) by week 6 or will something else happen? 3) When the time is unassigned I am assuming that is all backup images expiring. Will the tape be written to as long as it is in a Library or drive and not write protected .. every time a segment of images expire on the tape? 4) When that happens how does the time assigned change? Will it keep the initial time assigned or change to the Latest time assigned image? LTO MEDIA TAPE USAGE | Week 1, Write job| Week 2, Write job | Week 3, write job | Week 4, write job|Week 5, write job Any other information is appreciated concerning how this works. Thanks -T ___ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
Re: [Veritas-bu] Media Tape Writes and Retentions
On Wed, Feb 18, 2009 at 10:17 AM, Jackson, Todd < c-todd.jack...@invitrogen.com> wrote: > I have a question concerning LTO tape writes that I need some clarity > about. > The first thing to understand is that TAPE retention rarely matters. What really matters is IMAGE retention. > If you have a Retention of 5 weeks for a policy and you write a job the > first day which gives the > > Images 5 weeks until expiration. When you write to that tape again on week > 2, week 3 … etc. > > You really shouldn't do this especially if the images are for the same server's backups. If you write 5 weeks of the same server to the same tape, and your tape goes bad, you have no backups. > 1) Will each week of writes have a separate 5 week retention? > Remember that it's the images that matter. So yes, each image expires independently. > 2) Can the tape be written to again (over week 1 space on tape) by week 6 > or will something else happen? > You can only append to a tape. You will not write over any other part of the tape until all of the images have expired. > 3) When the time is unassigned I am assuming that is all backup images > expiring. Will the tape be written to as > > long as it is in a Library or drive and not write protected .. every time > a segment of images expire on the tape? > When all images have expired, the tape (by default) will move to the scratch pool and be eligible to be reused. Don't mix retentions on the same tape - this is the default. Putting one image on a tape with a 5-year retention will prevent you from re-using that tape for 5 years even if the vast majority of the images happen to have a 2-week retention. .../Ed Ed Wilts, RHCE, BCFP, BCSD, SCSP, SCSE ewi...@ewilts.org ___ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
[Veritas-bu] Media Tape Writes and Retentions
Hello All, I have a question concerning LTO tape writes that I need some clarity about. Scenario: If you have a Retention of 5 weeks for a policy and you write a job the first day which gives the Images 5 weeks until expiration. When you write to that tape again on week 2, week 3 ... etc. My question are 1) Will each week of writes have a separate 5 week retention? 2) Can the tape be written to again (over week 1 space on tape) by week 6 or will something else happen? 3) When the time is unassigned I am assuming that is all backup images expiring. Will the tape be written to as long as it is in a Library or drive and not write protected .. every time a segment of images expire on the tape? 4) When that happens how does the time assigned change? Will it keep the initial time assigned or change to the Latest time assigned image? LTO MEDIA TAPE USAGE | Week 1, Write job| Week 2, Write job | Week 3, write job | Week 4, write job|Week 5, write job Any other information is appreciated concerning how this works. Thanks -T ___ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
