bind memory usage

[JINMEI Tatuya / 神明達哉]

At Sat, 13 Dec 2008 11:50:52 -0200,
Leonardo Rodrigues Magalhães <leolistas at solutti.com.br> wrote:
 
>     i'm trying to run bind 9.5.0-P2 on a very low memory system. It's a 
> RouterBoard 450 with 32Mb RAM running OpenWRT.
> 
> root at sede:~# cat /proc/meminfo
> MemTotal:        29920 kB
> 
>     the problem is that bind seems to consume a LOT of memory ... well, 
> a lot for low memory devices, i never noticed that on machines with BS 
> of RAM.

[snip]

>     question is .... is there something i can do to low bind's memory 
> usage and successfully run it on those very low embedded devices ???

Admittedly, BIND9 tends to require a lot of memory.  I'm not sure if
it can reasonably function with a total system memory of 32MB.

Some related points:
- if you enable threads, disable them.  With the thread support BIND9
  will require even more memory.
- "max-cache-size 1048576" is a meaningless configuration:
             Any positive values less than 2MB will be ignored reset
             to 2MB.
  (from ARM)
- 'rndc flush' doesn't release allocated system memory.  It just
  frees all cache entries within the BIND9 process, so it's not
  surprising that you didn't see the memory footprint decrease after
  the flush operation.

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.