[OpenAFS] Re: Best way to debug "Lost contact with file server"

Benjamin Kaduk kaduk@MIT.EDU
Tue, 28 Feb 2012 19:56:30 -0500 (EST)

On Mon, 27 Feb 2012, Andrew Deason wrote:

> On Fri, 24 Feb 2012 02:51:48 -0800
> Ken Elkabany <Ken@Elkabany.com> wrote:
>> Off-email question: If a volume has N read replicas, how do clients
>> choose which one to use?
> By default, it's effectively random. Technically the client also takes
> into account the ip addresses of the client and server to try and
> estimate how "close" it is to each fileserver, but it does so using
> antiquated classful addressing techniques and usually isn't very useful.

Er, I would have thought that this would cause a group of clients deployed 
near each other to all prefer the same replica, which is not really 
"random".   That is, though from the point of view of a single client the 
choice may be random, from the point of view of managing server load it is 
not.  Is that incorrect?


> You can view the preferences the client is using by running
> 'fs getserverprefs'. You can set your own preferences to override the
> default semi-random ones with 'fs setserverprefs'. Servers with lower
> numbers are preferred over the others.