1st backup of client seems the fastest

[matt077]

Hi all, i'm just seeing if someone can shed any light on the below -

When backuping up a client, the 1st backup (which is a full backup) will run at around 218653kb/sec but if i run the backup again on the same client using the same policy (Full backup), it drops to around 118712kb/sec. Its picking up the same data, over the same network and to the same tape library. If i expire the images from the media and run the test again, the same happends.

[sdo]

Client type?  Is it a VM backup?  Or a plain client?  If plain, OS version?

[revarooo]

Have you actually timed the backups. Time the first backup then time a second backup. Is it the same, maybe a reporting issue

[sdo]

How big is the backup?  In fact, can you show us the activity monitor detail for both jobs?

[Mark_Solutions]

Lots of questions to answer so to add to them here are my thoughts:

1. Are you using dedupe, client-side, accelerator? .. thinking that is is spending time fingerprint matching on subsequent backups

2. Any other backups running at the same time? thinking it is queued for a while so the rate is actually an average of the whole backup period span .. and hence lower if it was queued.

So type of backup, NBU versions, where it is backed up to, what else is running .. all can make a difference.

[matt077]

Type of backup - Full backup of Drive C:/
NBU version - 7.6.1
Where is it backup to - VTL LTO 5 drive

System is only running tis backup. No other backups or services runnning on host.

1st backup -
Time taken - 3 minutes 15 seconds
kb/sec - 219,233
total backup size - 39,427,909

2nd backup -
time taken - 5 minutes 47 seconds
kb/sec - 118,296
total backup size - 39,431,386

[revarooo]

I assume these are all FULL backups?

What about 3rd, 4th, 5th and 6th backups time and speed?

Would need to see a detailed status output from the job to see how long to obtain resources etc.

[matt077]

Hi yes, all backups are full backups being ran.

I've notice the below which is little confussing -

1st backup - will run at 170,00kb/sec

2nd backup - will run at 93,00kb/sec

3rd backup - will run at 175,00kb/sec

4th backup - will run at 92,000kb/sec

and so on ....

The backups are of the same size too. I've also ran the same test on different clients and also differnt file paths but all seem to have a patten that every 2nd backup will run the quickest.

[sdo]

On the master, and on the media server, several times repetitively on each, do:

bptestbpcd -verbose -client myclientname

...is the same client always responding?  Or are you getting responses from different actual clients?

[revarooo]

Try sending the backup to a different storage unit (or even a NULL storage unit)

http://www.veritas.com/docs/000013708

If that shows the same behaviour, try a different type of client? Perhaps a unix client?

Same issue?

[sdo]

Good point revaroo... check to see if there are multiple storage units in the target storage unit group?  Are the backups always going to the same storage unit?