09-03-2012 02:39 AM
hello all
We regularly take backup for SAP systems, recently i faced some abnormal behaviour..
The policies configured 1 year ago are able to compress backup h/w level(tape drive level), but when i configure new policy with all parameters same... it is not able to compress
old policies can write 1.5 Tb data on single tape (IBM LTO 4 tape 800/1600Gb) , new policy is barely able to write 800Gb.
what is wrong with me ... even if i copy old policy to create new ..it wont compress.
what is the issue and the solution if any one have solved this issue....
on old policies software level compression is not enabled and still it compesses perfectly but new r not..???
Please Help!!!!!
09-03-2012 03:46 AM
A policy can't control compression on the tape drive level. But there are options that will prevent the tape drive from compressing data - that's the client side compression and encryption options. Please check those policy settings.
Please also check that in fact the tapes are LTO4. If LTO3 are used in LTO4 tape drives, they will be written in LTO3 format with maximum capacity of 400 (800 compressed).
09-03-2012 06:46 AM
Are there any difference between data to be backed up?
Compression ratio will become very low with some type of data (e.g. already compressed files like zip, gz, jpg, mpeg,....)
09-05-2012 04:47 AM
@ Nicolai
What are those client side settings ?? can u share any doc if possible..
and I am sure that I am using LTO4 tapes same as used with old policy there is no difference in tapes...
@ Yasuhisa
It is SAP application data archive which is same everywhere in my DC.
Is there any other option ????
09-05-2012 05:17 AM
Open the policy in qustion - check if the "Compression" or "Encryption" box is checkmarked.
Is the write speed of the tape drives affected as well ?
09-05-2012 05:31 AM
As the others have said - H/W compression is out of the hands of NetBackup and will be done automatically at the drive firmware level.
If you enable NBU encryption or compression then this prevents the drive compressing it at the firmware level
So any form of encryption or compression implemented prior to the data arriving at the tape drive will block H/W compresion
The only places this is set is on the Policy Attributes tab
Just one other thought ... is the NetBackup Key Management Service runnign on your Master?
09-05-2012 06:44 AM
Hello all
thanx for quick reply
There is no encryption or compression implemented in any policy
but how come some policies are able to write data in h/w level compression and other not
As i said i cross verified all the options used to create policies and also copied old policies to create new one so there is no chance that i have missed any settings..
can netbackup support will help me???? and if i want to try how and where???
let me know the contact info n mail ID to raise case for the same..
and also if u have any solution i can try that toooo
09-05-2012 07:05 AM
Go to http://www.symantec.com/business/support/index?page=home - click on the Contact Support on the right - get help by phone - choose your country
You may find that some systems have compressed file systems or encrypted file systems (forget the name of it now but Windows has new features for that) which slows thinsg down and reduces compression
Either that or you have a bad tape drive?
09-05-2012 09:10 AM
Is this only happening on SAP backups? If so, check the settings on your database and ensure encryption and compression have not ben enabled there.
Are all of the tape drives LTO4? If they are, be sure you have disabled compression option in the NetBackup policy. The LTO4 drives should (at least in our case) handle the compression automatically. If Netbackup compresses the data first, the drive cannot compress further.
09-06-2012 01:17 AM
I have tried with new and several tapes also still facing same issue..
all are LTO4 in SUN SL48 2-drives ...
HERE WHAT HAPPENING
I tried same data with old and new policies to write on same tape
with old policy it is compressing aroud 1.5 Tb but with new created policy it is not 800Gb this is the BIG JOKE... same data same tape-drive only diff is policy creation.
even i tried and created multiple policies for diff data it is not compressing
do I need to apply any patch ar update here ...
if u want any cmd uptput please post the full command
09-06-2012 02:15 AM
Can you post up ...
/usr/openv/netbackup/db/class/<working policy>/info
/usr/openv/netbackup/db/class/<non working policy>/info
Also, what happens if you 'copy to new the working policy to create a new one. Doe the compression work then ?
Martin
09-06-2012 02:20 AM
Sounds very much like a corrupted policy or one that has had encryption or compression enabled and then disabled but the change has not been updated somewhere leaving it as it was, even though you cannot see that in the GUI
You could run "nbpemreq -updatepolicies" to get the system to read-read all polices or just create a new one and discard the old one.
As Martin says - the info files may also hold the key.
09-06-2012 04:57 AM
Working policy: monday
as I already said copying working policy to create new also not able to compress(not working).....
09-06-2012 07:16 AM
dont copy it - the corruption will follow - make a new one or try the nbpemreq command
09-07-2012 12:26 AM
how do u come to know that there is corruption and imp how to avoid it from happening.
what nbpemreq command does .. any option with this cmd???
any precaution should be taken before execution of this cmd.. cause it is PROD and required policies are compressing properly, i dont wanna disturb that ...
surely i m looking for solution here but with all precaution...
09-07-2012 01:11 AM
From media management can you take a picture showing tapes that compress / do not compress. It important we get as much details as possible.
How do you determine that the tape only can hold 800GB ?
09-07-2012 01:38 AM
as u can see backup_STG_sunday / monday...... can write upto 1.5 Tb but while backup1-development has taken 2 tapes first tape filled .....
u can see the amount of data written is different in each policy while the data type is same for all policies..
backup_STG_sunday / monday..... are old policies others are new .
some can write upto 1 Tb also but lot policies are around 800 Gb only...
09-07-2012 02:40 AM
Are tape "backup1-development" status full ?. If the status is not full, there is still free space on them.
Are backup1-development and backup_STG* the same type of data ?
Have you tried to write backup_STG* to backup1-development ?
Could you also (physical) verify that both tape and drive really are LTO4.
The amount stored on the tape really look like LTO3.
09-07-2012 03:35 AM
As u can see from above 3 images backup1-development policy CI0081 L4 n 012349 L4 used in same write... please see 2nd image...
Yes All the tapes are LTO4 I am the one who handles all tapes and we have recently purchased IBM LTO4 tapes...
if u want me to try some workaround /options please let me know(same as backup_STG * using backup-dev policy...
I will try that this weekend..)
09-10-2012 03:26 AM
Please give us the full screen shot of the media so that we can see the Status of the tapes involved to see that they are all Full (or active or suspended)
Thanks