MetaSAN by Tiger-Technology
Review by Graeme Nattress
MetaSAN
is a SAN solution for OS X, Linux and Windows, but in this review,
I'll only be talking about how it works under OS X, and especially
how it works with Apple's Final Cut Pro video editing software.
What is a SAN?
A SAN, or Storage Area Network is a means of sharing storage
between computers. However, SANs are generally designed for speed,
and for working with very large amounts of fast storage, and
usually over fiber channel, rather than ethernet. We're all used
to sharing over an ethernet network and accessing the local storage
of another Macintosh. In this case, the local storage's host
computer will make sure that when you access a file, you have
permission to, and you don't try to delete it or alter it while
another computer is accessing it. However, this can often be
slow, even over gi-gabit ethernet.
When you connect a number of computers
direct to some storage, SAN software is needed to make sure that
multiple computers don't clash over their access to the files.
SANs are often connected together with fiber channel, a very
fast method of connection, but this does necessitate the use
of an expensive fiber switch. The upside of this though, is that
you can get very fast access to your shared storage: fast enough
for high end high definition work or many multiple users at standard
definition or with com- pressed formats. On the downside, while
large files like video come across the SAN fast, small files,
or file management actions on lots of files are significantly
slower. For video users, this is a small price to pay for the
benefits of collaberative workflows and access to large amounts
of fast storage.
Some SAN systems work at a "volume"
level, whereas SANs such as MetaSAN and Apple's
XSAN work at the file level. With a volume level SAN, a single
user has "write" permissions to a volume at a time.
This limits the flexibility and complicates workflows, and means
that your storage needs to be broken up into multiple volumes.
With a true file level SAN, you have much more flexibility because
locking is only done on a file level.
The Test System
Normally, due to the expense of a SAN system, they are generally
installed only in large production facilities where the added
complexity is a worthwhile trade for workflow efficiency. For
this review of MetaSAN, I'm going to install it in a very simple
system of two G5's that I would like to be able to access one
3.5TB Xserve RAID simultaneously. Each G5 has an Apple fiber
card installed. The first G5 is a dual 2ghz PCI model, that has
for over a year now had the Xserve RAID directly attached and
is used as my pri- mary edit suite. The fiber card has two 2gigabit
ports on it that were used to direct con- nect to the RAID. The
Xserve RAID is configured as two RAID 5, striped together as
RAID 0, giving me both speed and reliability.
The newer G5 is the Quad processor
model, and hence has the Apple PCI-e fiber card installed. The
Quad is used with Silicon
Color's FinalTouch. MetaSAN also needs a (preferably) gigabit
ethernet network to handle the transmission of metadata. This
metadata is not the files that you're transferring over the SAN,
but the control information that makes sure that file access
from multiple computers doesn't clash. I'm using a $100 Netgear
gigabit ethernet switch and two CAT5e cables for the metadata.
To test MetaSAN, I used a Qlogic
5200 switch, connected to the Xserve RAID and the two G5's
with Apple copper cables.
Installation
The first thing you should do before installing any SAN system
using existing storage is back up that storage. Luckily, my RAID
is not full and I was able to find room on my system to store
a backup of all the data. One of the nice features of MetaSAN
is that you can install and use it with your existing storage
without having to reformat or reconfigure the storage. Unlike
Apple's XSAN, MetaSan doesn't need a separate drive for metadata
and it doesn't use its own special formatting. This has tremendous
advantages, because it means any disk utilities you normally
use with your storage direct attached, will work with your new
MetaSAN storage, and if you disconnect your storage from the
SAN and revert is back to direct attached, it will function exactly
as it did before. Tiger-Technology, through their reseller network
can supply you with a 30 day trial serial number for the software.
The software installs quite easily, and appears as a preference
pane in the main system preferences. There are five tabs in the
MetaSAN preferences that control all operation.
The MetaSAN software is licensed
on a per-computer basis. The basic price is $995US.
Unlike Apple's XSAN, you don't need a dedicated metadata controller,
saving money on both the software license and the computer. This
alone makes the MetaSAN solution much more tempting for a small
shared storage system.
Once the software is installed,
the license key code needs to be entered to activate the software,
and this is easiest if the computer is connected to the internet
so that you can automatically get a license from the Tiger-Technology
server. If you're not connected to the internet on that computer,
you can also get a license manually. Once installed and activated,
an internet connection is not needed any more.
There are a few "gotchas"
in the installation of MetaSAN: You need to turn off the mounting
of non-san volumes > 2TB in size before trying to add them
to the SAN. This obviously applies to my RAID, and it took a
few minutes reading the PDF manual to spot this!
You need to be ever-so careful
that MetaSAN doesn't default to the wrong ethernet connection.
On my system, it defaulted to using my wi-fi connection for metadata
rather than the gigabit ethernet. This caused system instability
as wi-fi is not suitable for metadata transfer, and my wi-fi
connection can, at times, drop out, making it doubly unsuitable.
Setting Up MetaSAN
There are basically two stages to setting up the SAN. The first
is to select the storage, and the second is to connect the computers
into the system. Both are relatively easy, but it helps to know
the IP addresses of any computer you want to have on the SAN.
The IP address is used to "name" the computers on the
SAN, so it's important to get the IP address correct from the
start.
The main computer you install on
ends up being the initial metadata controller. There is a fall-over
scheme where other computers on the SAN can take over being the
metadata controller, hence you don't need a dedicated computer
to perform this function, but there's nothing stopping you using
a dedicated computer if you want to. After installing the MetaSAN
software on the other computers you want to add to the SAN, they'll
see the metadata controller and can be easily added, or, if you
want, you can add them from the metadata controller.
Once the computer has been rebooted,
it will see the shared storage. Installation can be as simple
as that, but I had issues where I accidentally had the metadata
network assigned to my wi-fi internet connection. To fix this,
I made a new SAN in MetaSAN, and made sure I didn't allow MetaSAN
to automatically pick an ethernet connection, instead, I assigned
it to the gigabit ethernet connection. Once the new SAN had been
created, I reassigned the other computer, and everything began
working great.
Speed
Other than allowing access to shared storage, the big thing you
want from a SAN solution is speed. There are many factors that
govern the speed of a SAN: the metadata network; the storage;
the fiber switch; and not least, the SAN software itself. One
of the main problems with testing the speed of hard drives, is
that every different disk speed testing application will give
different results. However, using real world tests in Final Cut
Pro, I found I can reliably work with many compressed DVCproHD
video streams on both FCP suites simultaneously, or edit DVCproHD
on one suite while playing 1080p30 uncompressed on the other.
I can get just enough throughput for two uncompressed 1080p30
streams and, the overall performance is very similar to what
I'd get direct connected to the storage, before I moved to using
MetaSAN. Using FinalTouchHD, I could play and color correct 1080p
HD footage in real time over the SAN.
Features
One of the best features of MetaSAN is that it is cross platform,
working on Mac OS X (Mac OS X on Intel support is in the works),
Windows and Linux. Couple this with the ability for your Windows
or Linux machine to access your HFS+ formatted file system, makes
for a very powerful enhancement for cross platform collaborative
workflows.
During operation, I found MetaSAN
to be very stable indeed. In testing, I removed the fiber connection
to one Mac, and MetaSAN then went into fallback MetaLAN mode,
allowing me to continue to access the SAN over the gigabit ethernet
network instead. MetaLAN is another SAN related product from
Tiger-Technology that allows for faster than normal sharing of
drives over ethernet. MetaLAN can be used with MetaSAN to provide
fast shared storage access to clients that cannot take a fiber
card, or where the expense and speed of fiber is not needed.
If you have computers on the SAN
with dedicated needs, MetaSAN can allow you to prioritize and
allocate bandwidth to client computers on the SAN. This can ensure,
say, a capture station has enough guaranteed bandwidth to capture
without dropping frames, no matter what demands are being made
by the rest of the SAN clients.
Conclusion
MetaSAN is a fully-featured SAN solution that is not only powerful,
cross-platform and affordable, but easy to set up, use and administer.
I recommend MetaSAN to anyone investigating a shared storage
solution, especially to any Final Cut Pro based production house
wanting to maximize their multi-station editing workflow.
Graeme
Nattress is a software developer who has been developing
cutting edge algorithms for the improvement of video quality.
Nattress Productions Inc
offers Special Effects filters and plugins for Final Cut Pro.
Graeme is a frequent contributor to the kenstone.net, LAFCPUG,
DV Info and DVX User websites and forums and is the www.red.com
Problem Solver.
copyright © Graeme
Nattress 2006