Re: [gentoo-user] Re: Strategy for using SAN/NAS for storage with Gentoo...

[Steve <gentoo_sjh@shic.co.uk>]

On 15/03/2010 18:21, Stroller wrote:
> It's hard to be more specific without knowing your usage.
Yes... I was deliberately vague to see what options came up... but I can
be more specific.  The budget is miniscule - and the performance demands
(bandwidth and latency) are completely non-challenging.  It's in this
context that I'm looking for reliability and availability... and I'd
like to have unix permissions working properly.  Security is a moderate
concern - the physical network is secured - but there is a broadband
connection which exposes various services.

> For storage of a "mere terabyte" you can buy a networked storage
> enclosure which will accommodate two drives. These are cheap, do
> mirroring, will accommodate standard 1TB, 1.5TB, 2TB drives, but are
> probably not too fast.

A cheap NAS enclosure is a definite possibility - there'd be no
performance issue - though this leaves three key questions:
1) Will it support unix file-permissions and can I be (fairly sure) it
will be secure if someone hacks my Wi-Fi?
2) Will I be able to put the (majority of the) gentoo filesystem on it -
or will I need to have a fully booted system to connect?
3) Can I use two entirely separate devices and mirror to both?  (I
expect the failure of the enclosure to be at least as likely as the
failure of a drive.)

> If you build your own server you can use software or hardware RAID.

Hmmm... building my own server - I've done that in the past, but my plan
is to minimize DIY with a view to minimizing the number of components
that might fail.  Ideally, I'd have four devices - one with a CPU and
memory (the server)... booting from Flash or CD or whatever  (+a
replacement in the cupboard); two separate boxes with drives in them
(mirrored storage); one (wired) Ethernet hub and broadband gateway.  I'd
connect to the network from a separate desktop/laptop to interact with
it - either locally or remotely.

> I wouldn't get too het up about Samba / CIFS vs NFS. Samba / CIFS can
> be faster than NFS, even in an all-Linux environment. Other times it's
> not. This seems pretty much random, depending upon whom is doing the
> benchmarking. On an intellectual level, at least, I find neither
> wholly satisfying - it would be really nice to have a Linux-native
> network filesystem that does authentication / permissions properly.
> But both do work.

Well the 'server' will be running Samba - and it's the back-end storage
for that I'm trying to resolve.  CIFS definitely looks problematic -
since Unix permissions for server data are one valuable separation
between publicly accessible services and my private data.  NFS might be
OK (it doesn't "feel" great) - though I *really* don't want to move from
one server to two when I'm aiming for reliability. 

> I looked at ZFS, but decided that Solaris, from a look at the HCL, was
> too picky over hardware. I think ZFS is great, I no longer think it's
> the future. My selection of cheap hardware is far wider under Linux, I
> can install Gentoo and just `emerge mediatomb` and stream movies to my
> PS3.
I like ZFS, conceptually, though I don't like Solaris.  I'm aware that
Apple have toyed with adopting ZFS and that it is available for BSD... A
*really* neat solution would be a (pair of) cheap NAS devices running an
appliance distribution of BSD with ZFS - exporting a NFS mount...
possibly over a VPN?  Hmmm - I'm trying to avoid complexity, too. Hmmm.