Multi node storage, ZFS

[Michal]

On 24/03/2010 17:14, Freddie Cash wrote:

> 
> Yes, that would be helpful (mirrored slogs, until we get slog removal
> support).
> 
> As would an L2ARC (cache) device in the head node.
> 
> As well as lots and lots and lots of RAM.
> 
> And as fast of ethernet NICs as you can get between the head node and the
> storage nodes.
> 
> And, and, and, and ... :)
> 

As far as I know more RAM is more important the fast CPU, so RAM is the
order of the day, and I guess it depends what you think fast CPU is, but
I wasn't planning on a duel CPU or anything top of the range. I have
some duel core's knocking around...I think testing will show how
good/bad my calculations/assumptions are. Most are done in batched,
nightly and weekly so extremely fast isn't THAT important as we are
looking at device/server backup's and stored data which is moved off
servers once a week. At the minute we are not looking at 100 user file
system or anything along those lines.

For NICS I can sort out a Gb switch or some point-to-point Gb
connections betweeen the nodes, there is also the option is trying
getting some cheap fibre cards (I have a few laying around) and a cheap
fibre switch (something off ebay for testing might do) to have fibre
between the nodes. This however all goes out the water for trying to do
replication to other sites which are 100mb lines, but for the minute I
will focus on 1 location to stop it getting too complex. There are quite
a lot of hardware things which need to be done correctly, and yes I do
need to look at lots of other things. But stage one is just getting a
few Storage devices talking to a Storage controller and seeing if my
ideas work (improve IO, improved redundancy, easy to add storage)

Michael, I sort of understand what you are talking about with ZIL, but
not completely, so thanks for the pointers, there are clearly things I
have not thought about.