Q: Xsan with RAID and Fibre switch only?

Navarro Parker - wrote:
If I have several Mac Pros with Fibre Channel cards and I want them all to connect to a single Fibre RAID, all I need is xSan and a Fibre switch?

No. You need a bit more than that. First, you will want to define a metadata controller and ideally a metadata backup. These systems should NOT be workstations. They should be dedicated devices focused on providing control for the SAN. The backup can be used to do an AFP reshare if needed but the controller should do Xsan, Open Directory (if needed) and DNS (if needed). Next, you need a second Ethernet network to run your metadata across. Xsan uses FC for data only. Metadata is sent across a dedicated, preferably non-routed, private network. Now, this is relatively easy and just about any 1000Base switch will provide.

An Xsan license is required for each San node. Thus, anything connected over FC will need a license. If you build this right, you will need to add two controllers to your current 3 workstations.

Does each Mac Pro need two Fibre ports on the switch? (So an 8-port switch would only give me 4 connections? Or rather 3 workstations and 1 to the RAID?)

As mentioned above, you will have at least 5 FC initiators (workstations/servers) and each can should have 2 connections each to the FC switch. Then assuming you have a Promise or Active array, you will (should) use all four connections from the storage array. This is 14 FC connections. Now, you have not mentioned backup. I am a fan of FC tape backup so that will be at least two more connections (one for the backup host and one for the lib). Now you are at 16 connections.

Since you hit 16, you should get two FC switches for redundancy. Now you can connect all devices to both switches and the complete loss of one switch will not take the SAN down. SAN is all about redundancy. Trust me, do it.

Xsan is not for the feint of heart. Do your research. Talk to your certified Xsan consultant for information and understanding.

Hope this helps

Navarro Parker - wrote:
Thanks for the detailed response. So I sounds like I still need to get an Xserve as a metadata controller, ya? Hoping to avoid the cost of one as I just need the pooled, fast storage across workstations.

Xserve or Mac Pro is your best bet. If you have Active Directory and don't plan to reshare the SAN over AFP/SMB, then you can go Mac Pro and avoid OS X Server. Oh, and realistically you should have two metadata controllers. I've built systems (under duress) with one but you are gambling with a lot of data.

Setting up an Xsan/Fibre/RAID solution doesn't sound as plug 'n play as I'd hoped. Is it not for tech DIY crowd?

Xsan is by far the easiest SAN to setup but it is not trivial. There are a lot of small details that need to be handled or you risk anything from poor performance to utter disaster. You do need to consider things like power, cooling and even weight. I built and support a 41 TB installation and we needed floor reinforcements.

The solution has its effective deployment locations. But, you need to examine the cost to benefit ratio.

Hope this helps.

Navarro Parker - wrote:
Again, thanks for the information. I guess my problem is that I have just 5 video workstations that need fast, shared storage. My current 1Ge connection to Drobos and small 5-drive Firewire800/eSATA RAIDs just don't have the performance I need.

5 stations is actually a lot. I support one SANs in an environment with only a single edit station (we do an AFP reshare however). And two SANs in environments with two edit stations.

GASP!!! Dorbo? Holy cow, run don't walk to something else. This is a bad choice of product to use for ANY data storage. We killed our demo unit so fast that the Drobo rep didn't even make it to the elevator. I urge you to look at other storage with extreme haste. I can not stress enough the number of personally involved horror stories related to Drobo and data loss. Be very careful and backup frequently.

xSAN/Fibre/Mac Pro almost seems overkill -- it could easily run $20,000 on the low end.

Try $80 to 100K for a properly configured starter system ($15,000 for each array * 2) + ($8000 per FC switch * 2) + ($7000 per Xserve * 2) + wiring, HBAs, transceivers, software, AppleCare, backup solutions, etc. It is pricey quick. I will agree.

It's a pretty deep price & performance chasm between 1GE and Fibre. Is there something in between?

Yes and no. Look at the products from CalDigit (http://www.caldigit.com/). This is a step up from Firewire based drives and an enormous leap away from Drobo. These units are fast, reliable, and the company has provided good support when a problem occurs.

The problem is that the CalDigit solution still leaves you with the underlying problem you have now... data isolation. You are silo'ing your data in individual islands and your editors can not share or distribute work unless you start sneaker netting everything as you are likely doing now.

Xsan provides a function possibly greater than the speed benefit (and the speed benefit is huge, don't get me wrong). Xsan is consolidating your content onto a single volume that everyone has access to concurrently. In addition, tools like Qmaster and Compressor become more powerful because you can use the cluster storage to provide the common storage for distributed rendering.

When a true cost analysis is performed, the speed benefit of a SAN and the additional capabilities like distributed rendering, data consolidation, Spotlight, etc, over traditional direct attached solutions proves the San's worth. Plus, when you start adding up all the money you spent, or will spend, on direct attached storage, you are probably already over $20k and still have all the headaches you had before.

Think in terms of an editors time. If they have slow storage they are dropping frames during an edit. This is slowing them down. If they have isolated storage then they are doing isolated renders that are taking all night. Plus, sharing content or moving projects to distribute workload takes half the morning. Consider the power and efficiency gain if you could cut a 2 hour render down to 20 minutes (times are used as illustrative, not representative of actual render). Plus, imagine not having to copy files anymore. Ah, nirvana. These things are possible allowing fast workflows, more efficient storage, and more flexible storage (you can expand an Xsan volume when you need more space).

Hope this helps