Should I enable DNS Scavenging on my DNS Servers? What are the implications? DNS DB location?

Alex John
Alex John used Ask the Experts™
Hi Experts,

I am running Best Practice Analyzer on all four of my DNS Servers (Server 2008 R2).

On all four DNS Servers I get the warning message stating that "The DNS server should have scavenging enabled" as the size of the DNS database can become excessive.

I am assuming the DB size is small, but how can I check?

Where is the location of the DNS database file so I can check whether the file is taking a lot of space?

If I enable scavenging, what are the implications? What could go wrong if it is enabled?
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Toni UranjekConsultant/Trainer

Scavenging removes stale resource records from DNS.
If you do not have aging and scavenging enabled records in DNS are deleted only manualy.

On Windows operating systems, DNS data can be stored in Active Directory or in dns file. DNS files are usually located in Windows\System32\DNS folder.
Shaun VermaakSenior Consultant
Awarded 2017
Distinguished Expert 2018

Do not set it too low, I recommend sticking to 7 days.
Setting it too low means it will get salvaged quicker than the actual refresh rate
Toni UranjekConsultant/Trainer

Aging and scavening intervals depend on DHCP lease time.

If you use default DHCP lease time of 8 days, it will work with default DNS settings. 7 days for no refresh interval, 7 days for refresh interval.

Aging and scavening interval should never be shorter than 24 hrs or else you could delete service resource records of domain controllers.
DrDave242Principal Support Engineer

It's unlikely your DNS database will grow large enough to cause problems; I don't think I've ever seen that happen, and as already stated, if your DNS zones are AD-integrated, DNS data is stored in Active Directory.

Having said that, implementing scavenging is almost always a good idea, but you should be aware of how it works before you do so. To that end, I highly recommend reading this TechNet blog entry from start to finish. It was written in 2008, but it's still relevant and very informative.

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