[mdlug] NAS Recommendations

[Adam Tauno Williams]

On Sat, 2014-03-15 at 10:25 -0400, Robert Adkins II wrote: 
> I think the first step in my server migration should be to review NAS
> solutions that will provide me with some flexibility and redundancy. 
> I would like some recommendations and suggestions based upon the things I'm
> looking at doing.

My suggestion would be to skip NAS and go with a SAN, especially as you
are doing visualization anyway.  A SAN makes for a simpler device, often
better performance, a clearer distinction between your storage network
and your application network, and is much more flexible [1]

Most SANs now support iSCSI [ethernet], Fiber-Channel, or ***direct
SAS*** connect [2]; using direct-connect SAS avoids all intermediary
hardware costs with the connection being as simple as a SAS cable [3] 

[1] if you want to host a Samba service for shared volumes, etc.... just
do that via a virtual machine hosting Samba services - you can upgrade,
configure, etc... in all the myriad ways Samba can be configured and
upgrade it whenever - otherwise you are limited by the vendor's updates,
supported configurations, etc...

[2] the limitation of direct SAS connect is the number of hosts that can
connect - usually 4.  But for a 'standard' virtualized cluster of three
hosts this works fine.

[3] iSCSI really demands secondary isolated Ethernet switches and
cabling and FC (the fastest solution) requires FoC adapters in the
servers and fiber-optic patch cables.

> Goals:
> Mount a share to the Virtual Email Server that will be used for hosting the
> /home directory structure for the IMAP service. Not allow this share to be
> accessed by client systems, except via email clients through the IMAP
> server. 
> Use the Samba PDC to authenticate users using the same mix of shares and
> permissions that I am currently utilizing. It's not an overly complex setup,
> but it's not a simple setup either. I also have strict size limitations
> enforced via partitioning in part to force myself to archive older jobs so
> that they aren't accidentally deleted or modified by end users long after
> the jobs have shipped.
> A separate location to store Virtual Machine images that could potentially
> still be accessed without the PDC operating in case the Host server
> completely dies, in order to be able to quickly bring up a temporary
> solution on other systems, while a new host server is procured.
>