Increasing Deduplication Performance on Server 2012/R2 … a bit

Updated 02.02..2015

It’s been a while since the dedup feature came to us with Server 2012.
Actually 2 years ago I started playing around and since then it’s one of my favourite features.
For testing purposes I have had deduped nearly everything I could and still use it in “unsupported” scenarios like non VDI environments.
I got quite an overview how rock solid this feature really is.

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DeDuplication Issues on Server 2012 – running out of space

DeDuplication is one of the coolest new features on Server 2012 and I can’t wait to get the new R2 with all improvements.

All (File) Servers I’m using are brand new setups but there is an older system which was 2008 R2 and upgraded inplace a couple of months before without worries.
There are many image files, drivers, backups laying around but the dedup rate was very low right from the beginning.

Usually I can see dedup rates around 40 – 50% on most fileservers. Sometimes much more especially If there are sys preps and Microsoft related stuff.
This one special fileserver was running out of space the second time and it seems there is a problem with the garbage collection.

I started a thread at the Technet Forum and got a couple of informations.

The interims solution for me at the moment is a powershell command to run the clean up manually and get space back.

PS C:\> Start-DedupJob E: –Type GarbageCollection -full

Within the next days I’m crawling a bit deeper and take a look into the system log trying to get more useful error messages or something.

Recreating AD DNS SRV records on server 2012

Today I installed a new Domain Controller and I got an interesting error which I’ve never had before on a couple of new Servers as I tried to put them in to the new and fresh created domain.

The Message was:
Note: This information is intended for a network administrator.  If you are not your network’s   administrator, notify the administrator that you received this information,   which has been recorded in the file C:\Windows\debug\dcdiag.txt.The following error occurred when DNS was queried for the service   location (SRV) resource record used to locate an Active Directory Domain   Controller for domain

The error was: “DNS name does not exist.”
(error code 0x0000232B RCODE_NAME_ERROR)
The query was for the SRV record for
Common causes of this error include the following:

- The DNS SRV records required to locate a AD DC for the domain are   not registered in DNS. These records are registered with a DNS server   automatically when a AD DC is added to a domain. They are updated by the AD   DC at set intervals. This computer is configured to use DNS servers with the   following 

IP addresses:

- One or more of the following zones do not include delegation to its   child zone:             
. (the root zone)
For information about correcting this problem, click Help.

I went straight to the DNS console and got confused as I couldn’t see any of the common SRV records at the _msdcs and so on.
After reading some threads and looking around I got it fixed and here is how I done it.

First of all you should check your DNS Settings as described here:

If it isn’t helpful you can try to do the same as I did and hack into the cmd  ipconfig /registerdns and dcdiag /fix.
After that  I restarted the DNS Server and netlogon service. Another dcdiag /a run later it almost ran through as usual and the missing records appeared in the DNS console.
The Servers I tried to join the domain went through the procedure and the problem was solved.

I learned two things.

First … It doesn’t matter how often you’ve done something and you believe it’s going well as everytime, you have to check it to be safe.

In my case I thought I’m installing an ADC as I done it hundred times before. I don’t need the usual check list.
This time I forgot to check the DNS records after setting up the ADC and creating the Domain.
Half a day later after creating dozens of groups, OUs, users and all this … You can image. 😉

Second … The reason of the problem was made by myself as I forgot to set “Register this connection’s addresses in DNS” checkbox at the advanced TCP/IP Settings before I installed the AD.

I’ve done that to avoid an entry to an existing DNS Server. It’s not unchecked by default. 😉

One of the heaps of different threads I found:

Server 2012 – SMB 3.0 Performance

Last week at the Hyper-V training course we had the opportunity to get a good view on Server 2012 SMB Performance.
The enhancement is really impressive.
The Server is distributing the SMB network traffic up to 5 ports and there is no need to team NICs or something like this.
It works… just like this. 😉

A picture is telling more than words.