Calculating digests issue

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Calculating digests issue

Veeam Logoby dvdrbc » Tue Mar 29, 2016 9:41 pm

Hi Guys,

I have a Linux VM that I replicate hourly. 2 nights in a row now the replication has taken 4 hours+ to replicate locally, it gets held up for a very long time on calculating digests of the hard drive.

I am replicating locally. My B&R Server/Proxy is in my head office (10.0.5.0 VLAN) and I replicate to the DR ESXi hosts in the building across the road connected via fibre on a different subnet (10.0.6.0 VLAN)

All the other VM's I replicate hourly function fine, yet this one has just started giving me troubles and I can't afford to be waiting 3 hours at the minimum. We are using V9 with the latest patch applied.

Can anyone offer any insight?

Image
dvdrbc
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Re: Calculating digests issue

Veeam Logoby foggy » Fri Apr 01, 2016 11:09 am

David, haven't you recently re-sized any of the source VM disks?
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Re: Calculating digests issue

Veeam Logoby dvdrbc » Fri Apr 01, 2016 11:52 pm

Hi Jim, no we haven't. I've noticed another 2 VM's having this issue also now
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Re: Calculating digests issue

Veeam Logoby Vitaliy S. » Mon Apr 04, 2016 9:42 am

David, maybe you have re-attached these disks recently? The reason for digest recalculation can be any modification of the source disk, which seems to happen in your case. Let us know what the subsequent job run will be, digest recalculation should not be happening.

On a side note, If you want to track changes for the virtual infrastructure configuration, please take a look at these Veeam ONE reports > VMware Configuration Tracking Report Pack
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Re: Calculating digests issue

Veeam Logoby dvdrbc » Mon Apr 04, 2016 12:17 pm

Nope, no disk reattaching, there has been no changes in our virtual environment for at least 3-5 months, and prior to upgrading to V9 I wasn't having this issue (could be completely unrelated though, so im not blaming the upgrade)

Also, the issue is happening on multiple VM's every single night some taking 45 mins minimum to calculate, some taking up to 5 hours

I'll take a look at the link
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Re: Calculating digests issue

Veeam Logoby Vitaliy S. » Mon Apr 04, 2016 12:37 pm

If nothing pops up after quick investigation, then ask our support team to look through backup job logs. There should contain some relevant information as well.
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Re: Calculating digests issue

Veeam Logoby readie » Fri Apr 22, 2016 7:43 am

After moving to a new VC (and running the migration tool from support) and remapping our VMs, I knew to expect a 'calculating disk digests', but these seem painfully slow, even to the extent that I am wondering whether a new full replication might be quicker.
We have two VMs which are each about 3 TB, made up of 6 x 512GB VHDs. Each of these 512GB is taking between 4 and 7 hours to calculate disk digests - which means the whole 3TB is going to take at least 24 hours . . .
Is this expected, or should I raise a support call?
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Re: Calculating digests issue

Veeam Logoby Shestakov » Fri Apr 22, 2016 10:31 am

Hello Bob,
The migration tool doesn`t help with replication jobs so digests need to be recalculated what indeed takes significant amount of time.
So yes, that`s an expected behavior.
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Re: Calculating digests issue

Veeam Logoby foggy » Fri Apr 22, 2016 10:42 am

Digests calculation depends on the data size. I remember previously it took roughly 1 minute to calculate digests for 1GB of data, though this was improved in one of the latest versions. But still, considering the size of your VMs, I'd say you're seeing an expected performance.
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Re: Calculating digests issue

Veeam Logoby readie » Fri Apr 22, 2016 2:14 pm

OK thanks both, I will be patient. I might do an experiment to find out if starting again with a fresh full might be quicker.
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Re: Calculating digests issue

Veeam Logoby Shestakov » Fri Apr 22, 2016 2:35 pm

It would be quicker if you created a new job since recalculation takes more time in most cases.
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