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Netbackup-compression of backup on tape (h/w level)

paroksha
Level 4

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!!!!!

31 REPLIES 31

Nicolai
Moderator
Moderator
Partner    VIP   

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).

Yasuhisa_Ishika
Level 6
Partner Accredited Certified

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,....)

paroksha
Level 4

@ 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 ????

 

 

Nicolai
Moderator
Moderator
Partner    VIP   

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 ?

Mark_Solutions
Level 6
Partner Accredited Certified

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?

paroksha
Level 4

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

 

 

Mark_Solutions
Level 6
Partner Accredited Certified

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?

RonCaplinger
Level 6

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.

 

paroksha
Level 4

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

mph999
Level 6
Employee Accredited

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

Mark_Solutions
Level 6
Partner Accredited Certified

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.

paroksha
Level 4

Working policy: monday

 

root@BackupServer #
root@BackupServer # more /usr/openv/netbackup/db/class/monday/info
CLIENT_TYPE 0
FOLLOW_NFS_MOUNTS 0
CROSS_MOUNT_POINTS 0
CLIENT_COMPRESS 0
PRIORITY 1
CLIENT_ENCRYPT 0
DISASTER_RECOVERY 0
MAX_JOBS_PER_CLASS 2147483647
MAX_FRAG_SIZE 0
ACTIVE 0
EFFECTIVE_TIME 1291635000
COLLECT_TIR_INFO 0
EXTENDED_SECURITY_INFO 0
IND_FILE_RESTORE_FROM_RAW 0
BLOCK_INCREMENTAL 0
STREAMING 0
FROZEN_IMAGE 0
BACKUP_COPY 0
NUMBER_OF_COPIES 1
FAIL_ON_ERROR 0
CHECKPOINT 0
CHKPT_INTERVAL 0
ENABLE_PFI 0
OFFHOST_BACKUP 0
USE_ALT_CLIENT 0
USE_DATA_MOVER 0
DATA_MOVER_TYPE 2
COLLECT_BMR_INFO 0
RES_IS_SS 0
GRANULAR_RESTORE_INFO 0
JOB_SUBTYPE 0
USE_VIRTUAL_MACHINE 0
GENERATION 52
CLASS_ID 5EF877A61DD211B2B3E400144F8CBB44
RESIDENCE BackupServer-hcart-robot-tld-0 *NULL* *NULL* *NULL* *NULL* *NULL* *NULL* *NULL* *NULL* *NULL*
POOL backup_STG_monday NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup
SHARE_GROUP *ANY*
DATA_CLASS *NULL*
#VMD5_DIGEST=11 ec 01 21 88 6c 46 87 4d 8a 80 48 5f c5 aa 03
root@BackupServer #
____ NON WORKING policy:backup2_QER_QBI
root@BackupServer #
root@BackupServer # more /usr/openv/netbackup/db/class/backup2_QER_QBI/info
CLIENT_TYPE 0
FOLLOW_NFS_MOUNTS 0
CROSS_MOUNT_POINTS 0
CLIENT_COMPRESS 0
PRIORITY 1
CLIENT_ENCRYPT 0
DISASTER_RECOVERY 0
MAX_JOBS_PER_CLASS 2147483647
MAX_FRAG_SIZE 0
ACTIVE 0
EFFECTIVE_TIME 1314264342
COLLECT_TIR_INFO 2
EXTENDED_SECURITY_INFO 0
IND_FILE_RESTORE_FROM_RAW 0
BLOCK_INCREMENTAL 0
STREAMING 0
FROZEN_IMAGE 0
BACKUP_COPY 0
NUMBER_OF_COPIES 1
FAIL_ON_ERROR 0
CHECKPOINT 0
CHKPT_INTERVAL 0
ENABLE_PFI 0
OFFHOST_BACKUP 0
USE_ALT_CLIENT 0
USE_DATA_MOVER 0
DATA_MOVER_TYPE 2
COLLECT_BMR_INFO 1
RES_IS_SS 0
GRANULAR_RESTORE_INFO 0
JOB_SUBTYPE 0
USE_VIRTUAL_MACHINE 0
GENERATION 66
CLASS_ID 343849061DD211B29A3900144F8CBB44
RESIDENCE BackupServer-hcart-robot-tld-0 *NULL* *NULL* *NULL* *NULL* *NULL* *NULL* *NULL* *NULL* *NULL*
POOL backup2_QER_QBI NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup NetBackup
SHARE_GROUP *ANY*
DATA_CLASS *NULL*
#VMD5_DIGEST=0a f7 0c fe 92 6d 1e 6c 48 b8 a4 20 9a 12 e4 09
root@BackupServer #
 

as I already said copying working policy to create new also not able to compress(not working).....

Mark_Solutions
Level 6
Partner Accredited Certified

dont copy it - the corruption will follow - make a new one or try the nbpemreq command

paroksha
Level 4

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...

 

Nicolai
Moderator
Moderator
Partner    VIP   

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 ?

paroksha
Level 4

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...

Nicolai
Moderator
Moderator
Partner    VIP   

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. 

  • 1.2TB on LTO3 is very often seen while backing up databases.
  • Around 1TB per tape using unstructured data (file,mail, etc etc)

 The amount stored on the tape really look like LTO3. 

paroksha
Level 4

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..)

 

Mark_Solutions
Level 6
Partner Accredited Certified

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