On Sat, 06 Feb 2016 14:58:34 +0000, John Rumm
wrote:
I seem to be sinking under a pile of spare hard drives at the moment -
typically 2.5" 500GB ones. It would be nice to find a way of making use
of them *cheaply*. It would be nice to build a NAS platform for use as a
backup repository, and for perhaps archiving stuff like films.
Performance is not that critical, but I would like fault tolerance. Not
too fussed about uptime. So it needs to be a RAID setup of some sort
that can survive any individual drive failure (e.g. RAID 5 or 6), but it
can be shutdown for maintenance etc without any worries - so I don't
need to worry about hot swap or redundant components.
A small low power mobo in an old PC case could be a starting point, or
for that matter, even as RaspPi 2 B or similar level single board
computer, but that will soon run out of sata ports (or not have any to
start with). One option that springs to mind would be a powered USB hub,
and a bunch of drive caddies which would be a cheap way of adding lots
of drives if required.
That then raises the question of software to drive it... How workable
would the various MD style RAID admin tools and file systems be at
coping with drives mounted on mixed hardware interfaces - say a mix of
SATA and USB? Has anyone tried multiple budget SATA cards on stock PC
hardware?
Yes and no (but probably more no as a solution for you). ;-)
My current server is an Dual Core Atom running 3 x 500G 2.5" SATA
drives on Windows Home Server V1. Two SATA are on board and there are
another 3 on a PCI card (1 used).
They used a technique that sounds like it would suit your needs (as
it still suits mine) in that you simply add drives to a pool (it's
easy to do because it's Windows g) and they can be any size or
interface. So, an old Mobo with 4 SATA and 2 PATA ports could use 6
drives straight away. It was called Drive Extender and the good thing
was the drives were just running straight NTFS and so each could be
read independently if required (unlike a single drive from a RAID 5
array)
As soon as the system detects a new drive it asks you how you want to
use it, either by adding it to the / a pool or as a backup drive. If
you have an existing pool of say 1.5TB and then you add another 500G
drive your pool then becomes 2TB.
Data redundancy is provided by folder mirroring where a mirrored
folder will be mirrored across two separate drives.
If a drive starts to play up (or you want to replace it with a bigger
one), you just remove it from the pool (all the data will
automatically be migrated to the remaining drives), you take it out,
fit the replacement and join it back into the pool.
Mine has been running every day for checks 1812 days:
https://dl.dropboxusercontent.com/u/5772409/WHS_V1.jpg
However, it is woken up by the first (Windows / Mac) client that turns
on and goes to sleep after the last client has shut down, assuming
there is no ongoing network or CPU activity above a certain threshold
or an unfinished torrent etc.
It also backs up all the Windows clients every day to the point where
if a client had drive fails catastrophically, I can replace the drive
and re-image the machine over the LAN in less than an hour and a few
clicks (and have done so a couple of times so far).
Or you can browse the list of backup available for each machine and
get a single file from say six months previous, depending on your
backup settings.
The backup system knows when it's backing up identical files from
different machines so only stores them once.
MS dropped WHS V1 (based on WS 2005) for WHS V2011 (based on WS 2008)
but you can still find copies on the likes of eBay.
I initially tried making a Linux server but gave up long before I even
considered the automatic (image) backup or all of the other features
that were so easy for me to install on WHS. I just wanted a NAS / file
server, not a new geeky hobby and was happy to pay the 45 or so quid
for the privilege.
Cheers, T i m
p.s. You can still get drive pooling on other Windows solutions (I
don't know which, I'm not a Windows fanatic) and you can also get
independent solutions like Drive Bender:
http://www.division-m.com/drivebender/
http://www.division-m.com/videos/drivebender-demo1/