ISCSI Vs Fibre Channel SAN

[Shane Sokolosky]

Hey Richard to answer your questions,

[Richard Milner] “What would the sustained throughput be per Gigbit Ethernet channel? 45Megabytes a second? — with audiodoes that come down to about 10 or 12 streams at one time?Or 20 to 24 streams?”

I’ve seen 55-65 MB/s depending on what kind of Ethernet NIC your using. How many audio tracks would depend on what format your working with (i.e. MP3, WAV, 24 bit, 16 bit?) just compare the data rate of that format to 60MB/s.

[Richard Milner] “What is the throughput for a 15 drive SAN or 7200 SATA drives (using RAid 3?)?
“
With Fiber Channel controllers you can get close to 400MB/s depending on how it’s made and setup.

I guess you could look at it like this- a Fiber Channel SAN is like the top dog with lots of speed (with 2GB you can get close to 200MB/s per connection) , iSCSI is like the small dog with limited speed (with GigE it’s just over 1/4th of the speed of Fiber channel).

Both are used to share media in a SAN enviorment where bandwidth is needed more than anything.
A typical NAS system over ethernet does the job but with very low bandwidth.

Shane Sokolosky

SAN Product Manager
ProMax Systems inc.
16 Technology Dr. Ste.106
Irvine, CA. 92618

Office (949) 727-3977 x108
Toll free (877) 776-6292
Fax (949) 727-7002
Website-https://www.Promax.com
shane.sokolosky@promax.com

[Richard Milner]

Shane,

Thanks for the response.

What about products and their costs?

Specifically, fibre channel and ISCSI costs per seat for both hardware and software. What are the choices in software for both Fibre and ISCSI?

[Michael Hughes]

What about products and their costs?

Specifically, fibre channel and ISCSI costs per seat for both hardware and software. What are the choices in software for both Fibre and ISCSI?

As far as iSCSI is concerned, I think it’s worth clarifying that iSCSI is actually a block level protocol (like FC except using an IP-based transport like Ethernet). When calculating costs, both FC and iSCSI based solutions require a SAN file system, managed via a Metadata Controller, running on every network client.

Where GigE performance is concerned, I think that the numbers that were quoted in a previous response were per client, not necessarily the maximum amount of data that can actually be supported per link. We’ve found that a single GigE link can be driven to ~110MB/sec. out of the theoretical limit of 125MB/sec. (1000Mb/sec.).

Another point to note is that network attached storage (NAS) devices are actually multi- protocol file servers that deliver file level services and don’t really have anything to do with the iSCSI protocol. Similarity is that both employ the same wire (i.e. GigE) to move the data. NAS devices do not require client-side software, and are typically much simpler to manage from an IT perspective than are SANs.

Regards,

Mike

[Larry Sherwood]

Is this the Michael Hughes I know and love?

LS

P.S. – sorry if it’s not the Michael Hughes I’m thinking of.

[John Mcclary]

With FC you get throughput of 200 (2Gb) to almost 300 (4Gb) megabytes a second. The “catch” is that with most FC systems (XSan, MPSan, etc) the system also needs a metadata server by ethernet – basically running two networks to achieve the highest speed and interoperability. This is why they are more complicated and usually cost more. Systems like Facilis Technology don’t need the metadata network because they don’t try to keep track of who last wrote to every sigle file, just by volume. This keeps the speed up and cuts down the cost premium.

When you’re looking at network speeds and costs you should look at total costs. Most companies aren’t wired with the Cat 5e cable needed for iSCSI (ours isn’t) so network cabling costs are much closer than they first appear (and optical cable is MUCH easier to string up).

The iSCSI system prices I was quoted a year ago were more expensive than the Terrablock solution was for the same capacity. Plus the Terrablock setup procedure was (1) string one optical cable per client and add the FC card (2) take the server out of the box and bootup, then (3) start digitizing video.

And I had no FC experience. If your workflow supports it, Terrablock is a great solution.

John McClary