[clamav-users] Linode Clam AV Updates

[Paul Smith]

On 20/03/2021 04:31, Joel Esler (jesler) via clamav-users wrote:
> Please check out cvdupdate or Freshclam for your updates.  Once or twice a day to check is fine.
>
FWIW, running cvdupdate only once or twice a day is a BAD idea.

If you are running a private mirror, then if Freshclam tries to get the 
latest CDIFF (according to DNS) from the private mirror, and it's not 
there, it immediately downloads the full CVD from the private mirror.

So, if CDIFF 26116 is advertised in DNS but has not been downloaded by 
cvdupdate yet, then the private mirror gets hammered by all the 
Freshclam clients getting the full CVD - and the next time all the 
Freshclams check, they will get the full CVD *again*, and *again*, until 
cvdupdate finally updates the private mirror with the latest CDIFF.

So, you need to run cvdupdate at least every hour or so, so that 
hopefully each Freshclam instance doesn't download the full CVD more 
than once per released CDIFF...

Hopefully there'll soon either be a documented way to run our own 
'DNSDatabaseInfo' server in conjunction with cvdupdate, or a Freshclam 
update will make it be less impatient before it downloads the full CVD 
after a new CDIFF is published.


-- 
Paul


-- 


Paul Smith Computer Services
Tel: 01484 855800
Vat No: GB 685 6987 53

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