[Gluster-devel] Choice of Translator question

[Kevan Benson]

Gareth Bult wrote:
> This could be the problem.
> 
> When I do this on a 1G file, I have 1 file in each stripe partition of size ~ 1G.
> 
> I don't get (n) files where n=1G/chunk size ... (!)
> 
> If I did, I could see how it would work .. but I don't ..
> 
> Are you saying I "definitely should" see files broken down into multiple sub files, or were you assuming this is how it worked?

That sounds like the striping isn't working, as you should see that if 
you were just doing AFR.

Everything I've read on the stripe translator, bot in the docs, and on 
the list from devs and people using it lead me to believe that when 
defined, the stripe translator should take files matching the naming 
convention and over the size specified in the "option block-size" 
translator option and break them into chunks, to be stored on the 
disparate shared the stripe translator defines.

Here's an example config that I would think should do this, all 
implemented on one system, with names to simulate their location if 
there were two different systems.  You should be able to use it as a 
client as well as a server config.

volume server1disk1
	type storage/posix
	option directory /tmp/server1disk1
end-volume

volume server1disk2
	type storage/posix
	option directory /tmp/server1disk2
end-volume

volume server2disk1
	type storage/posix
	option directory /tmp/server2disk1
end-volume

volume server2disk2
	type storage/posix
	option directory /tmp/server2disk2
end-volume

volume afr1
	type cluster/afr
	subvolumes server1disk1 server2disk1
end-volume

volume afr2
	type cluster/afr
	subvolumes server1disk2 server2disk2
end-volume

volume stripe
	type cluster/stripe
	option block-size *:1MB # Stripe files over 1MB in 1MB chunks
	subvolumes afr1 afr2
end-volume



I would think with this you would see 1000 files written to each 
"server" for a 1GB file write.  e.g.  500 in server1disk1 and 500 in 
server2disk1 for afr1, and 500 in server1disk2 and 500 in server2disk2 
for afr2.  Neither afr1 nor afr2 have a complete copy of the file, each 
have half of it, as the stripe translator striped it in 1MB chunks 
across them.


-- 

-Kevan Benson
-A-1 Networks