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low speed backup many large files

Ivan5
Level 0

Hello.

I have trouble with netbackup 7.7.3.

I want to backup img files of virtual mashines. But it takes a lot of times.

After first file copied, netbackup is waiting about an hour to start backup next file.

I’ve tried to disable compress.

How can I fix this ?

Thank you.

2 REPLIES 2

sdo
Moderator
Moderator
Partner    VIP    Certified

1) If the virtual machines are running at the time, then the backups are probably useless because AFAIK... RedHat KVM does not have an integration layer to stun / flush / snap the running virtual machines when a backup job begins, and so the VM is still writing to disk as and when the backups runs, and so it is quite easily possible to capture what is effectively a corrupt impression (backup) of virtual machine file-systems because the virtual machine file-systems are being written to by the VM at the very same time that NetBackup Client (on the KVM hypervisor host) is reading the IMG files..  AFAIK a backup of a RedHat KVM based virtual machine is only valid if the VM is turned-off / shutdown for the entire duration of the backup job.

2) Now then if you want to begin attempting to find out why the backup is slow then you need to enable bpbkar logging, see:

https://www.veritas.com/content/support/en_US/doc/86063237-127664549-0/v88899058-127664549

...this probably won't have all the answers but it is a first step in the right direction towards trying to find out what might be causing your problem.

3) If you want to find out how fast your backup client (i.e. RedHat KVM hypervisor host) NIC to NetBackup Media Server is, then can try to use a GEN_DATA policy.

4) If you want to find out how fast (without network and without NetBackup) is the RedHat KVM hypervisor host is able to read the disk storage that the IMG files reside upon, then you need to try a bpbkar to null speed test.

for both 3 & 4, see these:

https://www.mass.dk/netbackup-quick-hints/netbackup-admins-test-tool/

https://vox.veritas.com/t5/NetBackup/BPBKAR-TEST/td-p/633298

https://www.veritas.com/support/en_US/article.100030600

Nicolai
Moderator
Moderator
Partner    VIP   

Addition to SDO post:

The compression option in the policy configuration, enables software compression, performance will take a major hit so please don't enable it.

All modern tapes drives does inline compression using hardware that is superior compared to software based compression, so please leave "compression" in the policy unchecked.