Media Set not overwritting when append is full

[Cep]

Hi,

Currently we have BackupExec 12.5 on a w2k3 r2 server. The media set for our single backup job is set to 0 Hours Overwrite with infinite append.

For our backup job we set the job to append the media until no more space is available and then to overwrite the tape.

However this is not what is happening, once the tape reaches towards the end of its available space the software appears to be spitting the tape out and requesting another. This is not the behaviour set in its job and we have deliberatly turned off ejecting after job completion to test that the job is being spat out.

Why is this happening?

[HAMZAOUI_Omar]

Hi,

How many jobs have ?

To be sure use the same media for backups jobs, you can configure partitions on our robotic, and speciy the partition on your backup jobs.

Best Regards

[Ken_Putnam]

Once a job has started writing to a tape, and the tape fills up, BackupExec WILL NOT write to that same tape as overwrite in the same job, since that would effectively erase the first part of the backup.

Once a tape fills up, a job will ONLY continue on a scratch tape

[Scott_Meltzer]

Are you only using this single tape?  If so, Ken is correct, you can't both append and overwrite the same tape.    If you're using multiple tapes, make sure that the other tapes are part of the Scratch Media.

[Cep]

Hi thanks for the replies, they are much appreciated though I'm a little confused then by the option of "Append to media, overwrite if no appendable media is available" under options and also why you can set both types of protection to a tape if, from what you tell me, you can only do one or the other in the same job.

All our other backups are set up in the same way and re-use the same tape if there is not enough space for the job to be appended.

Our setup on all servers is a single selection list, a single backup job, a single media set as 0 Hours Overwrite, infinite append, 10 tapes on a two week rotation.

My understanding is that backupexec should check the tape to see if it can do the append job first before applying it?

[Ken_Putnam]

"My understanding is that backupexec should check the tape to see if it can do the append job first before applying it?"

BackupExec has never acted this way.  if your job is Append, it will see it one or more appendable tapes are mounted.  If so, it will open the oldest one. (it has no way of knowing whether this job will fit on that tape or not)  If the job fills the tape, it will continue ONLY on a scratch/overwriteable tape

" I'm a little confused then by the option of "Append to media, overwrite if no appendable media is available" under options and also why you can set both types of protection to a tape if, from what you tell me, you can only do one or the other in the same job."

"Append, else Overwrite" only applies to the first tape volume of a job.  If Backup Exec can see an Appendable volume (one that is in the same media set and has APP time left) then it will use that.  If it cannot, it will grab a scratch/overwritealble tape and use that (as opposed to Append only - If no appendable media is found, the job will end)

As for why you can have a volume that has both Append and Overwritesettings.  Say you want to economize on tape costs, so you stack al your  nightly jobs on one tape.  Set the APP to 1 day.  Say that your business requirements are such that you need access to your daily data for a month.  Set the OPP to 28 days 

for the basics of the BackupExec volume management philosophy (called ADAMM - Advanced Device and Media Management) see

http://seer.entsupport.symantec.com/docs/192265.htm

[ExtraLean]

"BackupExec has never acted this way. if your job is Append, it will see it one or more appendable tapes are mounted. If so, it will open the oldest one. (it has no way of knowing whether this job will fit on that tape or not) If the job fills the tape, it will continue ONLY on a scratch/overwriteable tape"

If that is the case, then what is the best strategy for preventing the need to use a scratch tape?

We are experiencing the same issue here, and it would be great to have it operate in such a way that if the backup won't fit on the current tape that it would remove one of the previous backups on that tape before starting so there will be enough room.  Is there a way to force BackupExec to check (or estimate) the size of the backup before starting and, if there isn't enough room on the tape, to remove the oldest backup on the tape to make enough room?

Any other ideas?  It is a major pain to keep switching tapes just to get the backup to complete.

Thanks!

[Ken_Putnam]

If that is the case, then what is the best strategy for preventing the need to use a scratch tape?

Any other ideas? It is a major pain to keep switching tapes just to get the backup to complete.

All you can do is run periodic Overwrites, with Appends added. Perhaps a Weekly Overwrite with daily Appends, or  depending on your data size, perhaps an Overwrite on Friday and Tues, with Append on Mon , Wed, Thur

[ExtraLean]

"All you can do is run periodic Overwrites, with Appends added. Perhaps a Weekly Overwrite with daily Appends, or depending on your data size, perhaps an Overwrite on Friday and Tues, with Append on Mon , Wed, Thur"

Thanks for the info.  I wonder what is the best way to accomplish this.  I currently have a single job set up that uses the following tapes for rotation:

Monday (Week 1)
Tuesday (Week 1)
Wednesday (Week 1)
Thursday (Week 1)
Friday (Week 1)
Monday (Week 2)
Tuesday (Week 2)
Wednesday (Week 2)
Thursday (Week 2)
Friday (Week 2)
Friday (Week 3)
Friday (Week 4)

So, it takes several weeks for the tapes to get full, but then the problem the original poster mentioned starts to take place.

The current job is called Full Nightly Backup.  Would it make sense to just copy that job to a new job called Full Nightly Backup with Overwrite, and then just modify the schedules on them both so they don't overlap?  I'm new at this and just want to make sure that I understand you correctly, and/or if you have any other ideas or suggestions to accomplish what you mentioned in your previous reply.

Thanks!

[Ken_Putnam]

So, it takes several weeks for the tapes to get full, but then the problem the original poster mentioned starts to take place.

the first thing that comes to mind is "Bite the bullet and buy more tape"  I know this can get expensive in a hurry, but how important is your data to your business?

Also remember that if you do all Append jobs, when you finally have to overwrite, ALL of the data on that tape is GONE

A few questions:

do you do fulls on all jobs, or Fulls on weekends and INCR/DIFF on week days

How long to you need to keep nightly data?  weekly data?

[ExtraLean]

"the first thing that comes to mind is "Bite the bullet and buy more tape" I know this can get expensive in a hurry, but how important is your data to your business?"

That is a very good suggestion, I'll have to bring that up.  We also do nightly off-site online backups as well so there is an extra layer of protection there as well.


"Also remember that if you do all Append jobs, when you finally have to overwrite, ALL of the data on that tape is GONE"

Hmmm... Thanks for that info.  I was wondering if that was the case.  Too bad it doesn't just overwrite the oldest backups on the tape ;-(


"do you do fulls on all jobs, or Fulls on weekends and INCR/DIFF on week days"

Yes, full on all jobs.  (There is currently only one job, and it is doing a full backup.)


"How long to you need to keep nightly data? weekly data?"

Well, considering they are all full backups it essentially creates a "working copy" each day.  The probability of needing to retrieve an old "working copy" would be a low.  So, thinking out loud here, would it make sense to just switch everything to overwrite all the time?  Since we have two weeks worth of Full Backups at any given time that would mean we could go back for two weeks if we had to...  Would that be correct?

The down side would be that it limits us to only two weeks of recoverable data, correct?  Any other stuff I'm missing, any other reason why this would NOT be a good idea, or any other suggestions that are completely different?

[Ken_Putnam]

Most of the places that I have worked for keep daily backups for a very limited time - one or two weeks.  Weeklies for much longer  4-6 months, and Monthlies either for a year, or forever (depending on legal requirments)


if you can get four jobs on one tape, and only two weeks of dailies would work for you, I'd say do an overwrite on  Monday and Appends on Tue-Thu, have two tapes and change them out weekly.  Monday job should  be Overwrite, others Append all to the same media set.  Opp of 6 days, APP of 5 days


Weekly job to a different media set, always overwrite, no APP with OPP of however long you need to keep data (and as many tapes as needed to flesh out the scheme)

[CFelder]

I am experiencing the "Media Full" problem where the tape is ejected and a request for a new media is made. I am new to this as well, but the append and overwrite schedules seem to complicate this process.

From the previous post and responses, I gather this is because of the append to media settings.

I don't have any issues or constraints with regards to purchasing additional tapes, I just don't think its necessary.

I swap tapes every night using one tape for each night. They are labeled "Monday"..........."Friday". I have a daily job that runs each night.

When I view the properties of my Media Set and a particular tape ( in this case the one labeled Monday) this is what I see.

Media Set:
Overwrite Protection period: 4 Hours
Appendable period: Infinite - Allow Append

Monday's Tape:
Overwrite Protection until: Overwritable
Appendable Until: Not Appendable (Media Full)

When Monday's tape is in the drive and the daily job runs Monday night, the data that is getting overwritten is last Mondays data, since I recycle the tapes each week. In this scenario, I'll always have the last weeks data right, albeit each day of the previous week would reside on its own tape. Wouldn't my scenario work error free if I change the overwrite settings to "None"?

Any assistance is greatly appreciated.

[Ken_Putnam]

 Wouldn't my scenario work error free if I change the overwrite settings to "None"?

I've seen some REALLY screwy things happend with a Global Overwrite of NONE

If your jobs are defined as OVERWRITE, you scheme should work, if they are all APPEND, when the tapes finally fill up in the middle of the job, you will get the "Insert Overwriteable" prompt