Veritas-bu

[Veritas-bu] duplication speed

2006-02-01 09:26:57
Subject: [Veritas-bu] duplication speed
From: dave.markham AT fjserv DOT net (Dave Markham)
Date: Wed, 01 Feb 2006 14:26:57 +0000
I have 4 drives and am multiplexing things so all drives are in use 
which i suppose is how i backed things up in 8 hours and yes i gave 2048 
set for frag size ( which i've just thought is 2 meg not 2 gig isnt 
it....one to change )

I have worked out the duplication has picked its first image, then 
mounted that tape and found other images on that and has started 
duplicating them. What it hasnt done is realize other images to be 
duplicated ( found with the bpduplicate -PM option ) are on different 
tapes and then mount them in the other drive.

What i have done is to launch another bpduplicate with the -policy flag 
as i have worked out they are on different tapes than the ones already 
in progress. I assume when the original job tries to duplicate ones 
further down the list it will realize a job has already begun to do 
that.....I hope so anyway.

The percentage figure jumped from 1% to 6% when it had finished the 
first tape on the sets it is doing.
That still was going to be out of time however as 6% in 140 minutes 
meant it would take 38 hours for the whole thing to complete. ((100/6) * 
140) / 60

This is bad as im moving everything tomorrow at 4pm eek.

D




Ed Wilts wrote:

>On Wed, Feb 01, 2006 at 12:14:25PM +0000, Dave Markham wrote:
>  
>
>>People i am moving an infrastructure from one site to the other. As part 
>>of this we are splitting things between different trucks for resilience.
>>
>>    
>>
>How long did this backup take?
>
>  
>
>>I am slightly concerned as it reckons the job is only 1% through on the 
>>gui.
>>    
>>
>
>I never trust the % complete.  It's rarely right.
>
>  
>
>>When i run iostat -xn |egrep "rmt/0|rmt/2" i can see around 5mb/s which 
>>is about right for the DLT7000 drives i have in the L1000.
>>    
>>
>
>  
>
>>There are 32 images in total to duplicated and the backups took around 8 
>>hours to complete 290 gig. 
>>    
>>
>
>At 5MB/sec, that's 18GB per hour.  To back up 290GB would take 16 hours.
>I don't see how you completed this in 8 hours unless you were doing a
>lot of compression.
>
>I need the duplications to be finished by 
>  
>
>>tomorrow and as it has been nearly 2 hours now and saying only 1% 
>>complete im worried it wont be done.
>>    
>>
>
>Can you estimate the actual speed by how fast it's changing tapes?  A
>DLT7000 is only 80GB compressed so you should be changing tapes every few
>hours.  290GB in 8 hours is 36GB per hour so that would be a fresh tape
>every 2 hours tops.  
>
>  
>
>>I am wondering what file num =  Surely its not actually a file number 
>>and its only written 23 files in 2 hours.
>>    
>>
>
>Are those 2GB file fragments?  If so, that's about right - 46GB in 2
>hours or 23 GB per hour - that's better than 5MB/sec.  That would put
>your total time to complete at about 13 hours.
>
>        .../Ed
>
>  
>


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