DragonflyBSD NAS cluster

[Patrick Marchand]

Hello,

First time poster to this list. I'm a linux and OpenBSD sysadmin
from Montreal, Quebec. I also organize the (freshly minted) Montreal
BSD user group.

I've played a bit with DragonflyBSD before, but my experience is
still mostly limited to reading documentation and mailing lists.
I'm planning to build a replicated file server but I had a few
questions beforehand, mostly related to installation.

I bought two HP t620 thin clients on Ebay, see
https://www.parkytowers.me.uk/thin/hp/t620/ for more information.
The BIOS dated back to 10/09/2014, but I managed to flash them with
the latest version (03/05/2019).  I've upgraded them from the initial
4GB of DDR3 RAM to the maximum of 16GB of DDR3 RAM. They came with
no disks, but have m.2 SATA and mSATA connectors along with internal
USB slots. I've given each a 24GB mSATA SSD and a 1TB m.2 SATA SSD.

Does anybody have recommendations as to how I should set these up?
This is mostly an experiment, so scalability and reliability are
only of theoretical concern.

Main questions:

Should I put the OS on the mSATA SSD or use it as swapcache(8) ?

If I'm using the mSATA SSD for the OS files, can I have part of my m.2 SATA SSD handle swapcache ?

If I use a swapcache, how much should I use? (Depending on the
answer to the questions above)

Could the OS files be kept on an internal USB key ? (Not sure that
would even boot..)

I'm planning on having my router be able to PXE boot some other
machines, would it make sense to PXE boot these machines as well ?

hammer secondary PFS are read-only, I believe hammer2 secondary PFS
can be read-write, but I'm unsure how far along this is. So should
I be using hammer or hammer2 for network replication of a PFS ?

If hammer2 can handle a read-write networked secondary PFS, can I
then export the filesystem with NFS and put them behind a load
balancer ?

If hammer2 cant handle this yet and if I'm using the mSATA SSD as
swapcache, can I use hammer2 for my system files and hammer for my
data files ?

Any other ideas, warnings, links to posts or tutorials would also be welcome.

Merci !

-- 

Patrick Marchand
https://www.patrick.marchand.ski