A Poor Man’s SANS

“Unless you have an Xsan (fibre) set up you can't edit over a network, it is too slow. You need to have external scratch drives at each seat.”

Well, not exactly…

No, you can't edit video on the Xserve. And No, you can’t edit video over a typical network. For one thing, Mac OS Server can't do it by itself. Too many bottle-necks. But, YES, you CAN edit from a network location, if the configuration and hardware is right.

Folks, Yes you Can! You CAN edit footage from a central location (notice I did not say Server), without a FiberRAID system. It's called "Video-Over-Gig-E" on the street. We are doing it. Have been for a year. Our main goal was to allow a student to sit down at any station and edit their project, no matter where the project was started, no matter where it was captured/transfered. So, we did some research. Now listen, I’m no Network Specialist, and I don’t pretend to fully understand it all. But, I will gladly share with you what we are doing here, which works. This is how we have 10 Final Cut Pro stations, all sharing the same “Shared Video Drive”.

Not only can any of these 10 stations open a particular project, we have actually had all 10 stations open the SAME project at the same time! Of course, this is not practical, because the last person that saves the FCP project, overwrites everyone elses. But you CAN have 10 separate stations all editing the exact same video clip at the exact same time! Yes, you CAN. Please note, we edit in HD, Apple ProRes422 (1920X1080). Do the math, we should get 3 HD streams per station, up to 10 stations. We’ve tested this, it works without a glitch, NO DROPPED FRAMES.

First, you should know that this setup is NOT using a Mac Server. This is using a dedicated Mac Pro with the video drive setup to be shared. Are you ready? Shared using Apple File Sharing, or Apple Filing Protocol (AFP). That’s right, DO NOT USE Mac OS Server! Here’s the deal, right now you can share from one Mac to another, even EDIT footage from another machine in Final Cut Pro, using AFP.

But wait, that’s not good enough! You want multiple machines to be able to share this same “Shared Video Storage”. Geeez, whadoyawant for crying out loud!

First roadblock; your ethernet port may be too slow. It MUST be a Gigabit 1000Mb/s port. A Gigabit ethernet port is typically fast enough for about 3 HD streams. (Apple Prores 422 HD)

This must be a dedicated ethernet port for video only. We use one port on our Mac Pro, manually configured, to be the dedicated port for the shared video storage. The second port is for internet and Xserve access, and is connected to another switch. If you have iMacs, you would have to dedicate the Ethernet port to be manually configured for the shared video, and use the built-in Wi-Fi for internet or other network use.

Chas01A VERY IMPORTANT configuration change, pertaining to each stations ethernet port for video only, involves what is called Jumbo Frames1. There is a “magical” number to set your manually configured video port to. Ours is set to 8100.

Second roadblock; your ethernet switch MUST be Gigabit, with the fastest backplane you can get. There are a short few on the market that are fast enough. This switch must also support Link Aggregation2.

Also, you MUST eliminate all network and internet traffic from this “dedicated video switch”.  In other words, you need a switch that has NOTHING connected but your MAC stations, including the station that has the video storage RAID on it. NO GATEWAY to the internet, NO connection to your school network.

Chas02Third roadblock; the ethernet path to the "Shared Storage" station MUST be MUCH FASTER than one Gigabit. Obviously you will want more than one Mac station able to access the video files simultaneously. So, if each station has one Gigabit path, then the station with the Shared Video Storage, would need multiple Ethernet paths connected to it. It only makes sense, right? What would happen if you had a 10 lane highway where all traffic had to merge into one lane to get to its destination. Major Traffic Jam. To overcome this you install a six port Ethernet card into the Mac Pro where the Shared Video Storage will be connected. We use this one by Smalltree.

Chas03Earlier, I said the switch must support Link Aggregation. Link aggregation is trunking multiple data lines into one. Our switch supports Link Aggregation for 6 ethernet ports to be connected as 1. It sees it as 1 data path. Think of it like this; it combines 6 separate highways into one 6-lane highway. In a way, you now have 6 times the speed to this one Mac Pro that has the Shared Video Storage on it. The crazy side of me calls this FM, or “Freakin Magic”!

STOP here. If you’ve done all of the above, then any or all of your Macs can “see” and share files from this one Mac Station from any shared drive on this Mac station. (Sidenote: 1 drawack. You can only have 10 stations logged in at one time using AFP).

Fourth roadblock; the "Shared Storage" must be fast enough for multiple Macs to be reading & writing to it at the same time.

We purchased a 16TB Storage unit (upgradable to 32TB) from Maxx Digital.

Chas04You can get your own from anywhere, SAS (Serial Attached SCSI) is what ours is, therefore theinterface I recommend. The package came with the SAS controller to install in the Mac Pro, which is connected to the external SAS 16TB storage. It is in a RAID5 configuration, consisting of 8 2TB enterprise drives. (Enterprise drives are designed to run 24/7). We get a little more than 13TB available, due to the nature of RAID5. You can read up on RAIDs to learn the different configurations. RAID5 not only speeds up the data throughput but gives us redundancy. In other words, if one drive fails, I can hot swap it, without losing ANY data. We do not worry about backing up videos anymore! As for speed, for any of you that believe in numbers, we are getting 750MB/s speed on this RAID. That’s FM!

Now, in Final Cut Pro 7, my students MUST always set their Capture Scratch to a specified location on the Shared Video Drive. They also must be sure and save their project to that same specified folder on the Shared Video Drive. This way they can open it on any station on the network. They have a login, an AFP account on the Mac with the Shared Video Drive. You can have as many login accounts in AFP as you want, just only 10 connected at once.Chas05

There you have it. What did we gain by doing this ourselves? It cost us under $10,000, vs. a $50,000 fibreRAID system. We’ve been running this more than a year now. I should mention, we’ve not figured out how to have DVD Studio Pro burn if the media is not local. We also tend to have a little trouble with Motion, so we edit all Motion projects local as well.

Oh yeah! Here’s our latest COOL addition. We have a program on one of the Mac Pro’s called On the Air Video Express ($500), and this Mac has a Blackmagic card in it, allowing us to use it as a Playback machine for our daily LIVE broadcast. So, when a student finishes a project ON ANY STATION, it is exported in QT current settings (HD). Then our Playbacks operator loads that HD clip up, and it’s ready for AIR, playing LIVE off the Shared Video Drive! No need to copy elsewhere.

I’m done. Don’t hate. We worked very hard for this. It’s cheap, comparatively speaking.

If you decide to try this, feel free to contact me via email, I will share more detail on all of the steps listed above.

Coming soon, I will report my results of using Final Cut X on our Poor Man’s SANS.


Charles Aldridge teaches Audio/Video Production at Texas High School in Texarkana, Texas.  He has taught for 18 years. Charles has a background in Electronic Engineering email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it website: www.tigervision.org


Note 1: What is Jumbo Frames?: http://en.wikipedia.org/wiki/Jumbo_frame
Note 2: What is Link Aggregation?: http://en.wikipedia.org/wiki/Link_aggregation