10-17-2019 06:10 AM
Hello,
Am really new in netbackup, we are currently running verita netbackup on redhat 6.5, with LTO3 tapes, over time have made an obsevertion in some volume pools:
Am really afraid we are running out of tapes.
10-17-2019 06:23 AM
The most common causes of under utilization are;
Golden Rule is to reduce complexity in all aspects of your NetBackup environment. That goes for policies, retention periods,volume pools, etc. If you there is no specific requirement to have more than one of ANYTHING do not create more than one.
Examples.
You've got 100 Windows servers in your environment. How many policies do you need?
Answer: 1 (assuming no apps / databases and that you back them up exactly the same, schedule and backup selection)
Only when someone makes a case for having a different schedule or backup selection do you need to create another policy.
The same goes for pools.You can probably get away with Daily, weekly, monthly and quaterly or yearly if there is a requirement for that. But once again, only if there is a requirement.
Hope that makes sense :)
10-17-2019 08:04 AM
Thank you for the prompt reply,
Its true we have many volume pools, and the paticular one with more un utilized tapes is the one that were use more often for weekly backups. Shows tapes which are not full, active but not in the Robot Control Host, others are last mounted in around 2010 but never wirtten and not in the Robot Control Host.
What is really puzzling, is that tapes which are 800GB getting full at 200GB, and its becoming more regular this year. When no changes have been on pools, retentions(increase in the pool numbers)
10-17-2019 09:00 AM
LTO3 native capacity is actually 400GB. You get 800GB only if you are lucky with perfectly compressible backup data. If you backup compressed database dumps to LTO3 then you will never get more than 400GB on a tape. If your backups are slow and cause lots of streaming gaps then you could get as low as 300GB on a tape.
LTO tapes should be good for around 260 full writes/erases by NetBackup, see:
https://docs.oracle.com/cd/E38452_01/en/LTO6_Vol1_E1_D7/LTO6_Vol1_E1_D7.pdf
...so that usually means 260 mounts in NetBackup.
Why 260 mounts, when a tape might be rated for 16,000 full winds and rewinds? Because to fill an LTO tape just once means that the tape will have to fully wind forwards and fully wind backards many many times even just to fill a tape once, due to tape tracks, see:
https://en.wikipedia.org/wiki/Linear_Tape-Open
...yet this old guide suggests 364 full writes for LTO3:
10-17-2019 09:02 AM - edited 10-17-2019 09:03 AM
You say you have tapes from 2010, how many mounts have your problem tapes had ?
Ever lost your catalog, and lost the history of tape mounts ? Maybe your tapes have actually had many more mounts than even NetBackup knows about right now.
10-17-2019 08:58 PM
10-18-2019 12:01 AM
My 2c about some of your statements:
.....Shows tapes which are not full, active but not in the Robot Control Host, others are last mounted in around 2010 but never wirtten and not in the Robot Control Host.
So, this means that these tapes are not in the robot, right?
Do you know where they are so that you can put them in the robot for backups?
NBU will never request tapes for backup if they are not in the robot.
What is really puzzling, is that tapes which are 800GB getting full at 200GB, and its becoming more regular this year.
This is not a NetBackup issue.
Please see this excellent answer from @mph999 :
https://vox.veritas.com/t5/NetBackup/The-backup-size-on-the-tapes/m-p/710551#M190323
and https://vox.veritas.com/t5/NetBackup/Data-storing-issue-on-Tapes/m-p/662369#M173226
It seems all of your infrastructure is very old - your hardware and software ran out of support many years ago.
Current LTO technology is at LTO8 and NBU version at 8.2.
Maybe your management need to consider upgrades?
10-18-2019 04:00 AM
Thanks Marianne, I tried to post similar last night but it was showing an error.
Here is the technote that explains the same, if you.want something more official.
https://www.veritas.com/support/en_US/article.100014480.html
10-18-2019 05:27 AM
- Have 3 tapes have active media status, 2 have never been written on(one mounted in 2018 and the other 2009), the other one was last written on 2017.
-4 tapes show media status Active but not in the library.
Ever lost your catalog, and lost the history of tape mounts ? Not really sure
10-18-2019 05:31 AM
Hello,
How do I check regularly is for tapes that are frozen and max number of partially full tapes is reached.
10-18-2019 05:32 AM
Can you please show us the following output for one of these tapes?
nbemmcmd -listmedia -mediaid <media-id>
As per my previous post - tapes that are not in the library will never be requested for backups.
10-18-2019 05:37 AM
@Ejustin wrote:
Hello,
How do I check regularly is for tapes that are frozen and max number of partially full tapes is reached.
You can run reports such as 'Tape Summary' report with 'Verbose' option selected.
Another handy report is this one that can only be run from cmd (in ...\netbackup\bin\goodies directory):
available_media
If there are too many lines in the output to fit on a single screen, send the output to a folder that exists, e.g.
available_media >C:\temp\media.txt (assuming that C:\temp folder exists).
10-18-2019 05:50 AM
which directory do I run this command from (bemmcmd -listmedia -mediaid <media-id>)
10-18-2019 06:04 AM
nbemmcmd is in ...\netbackup\bin\admincmd
10-18-2019 07:26 AM
[root@####### admincmd]# bemmcmd -listmedia -mediaid 0187L3
-bash: bemmcmd: command not found
[root@####### admincmd]# pwd
/usr/openv/netbackup/bin/admincmd
Could there be anything am missing out?
10-18-2019 07:28 AM
10-18-2019 08:45 AM
Hello,
Thank you for your prompt response, have tried running the command:
[root@####### admincmd]# nbemmcmd -listmedia -mediaid 0187L3
-bash: bemmcmd: command not found
10-19-2019 04:54 AM