[NTLUG:Discuss] Re: Practice with clustering at home? -- summary of external busses ...

[Bryan J. Smith]

In a nutshell, here are a list of external devices.
It's more than just USB v. FireWire out there.
Again, FireWire is not a good option for this.

USB:  Abysmal range, low-to-mid speed
2 dumb data wires, multi-targetting not even an option. 
Doesn't support device-to-device transfers, much less
multi-targetting.

FireWire: Short-range, mid-speed
4 data wires, good software standards, device-to-device
transfers, improperly assumed to be and often used as a
multi-targettable bus.  It is not.  You'll get issues and
then just total data loss (like one company did rather
quickly and I did a big ass "I told you so" at the end).

SCSI:  Short-range, high-speed
Can be made multi-targettable with intelligent end-devices. 
Used to be expensive, but you can get things off of eBay and
other places for low-cost these days.  <- Good option?

SATA:  Short-range, high speed
Doesn't support device-to-device transfers, much less
multi-targetting.

SAS:   Short-range, high-to-very high speed
Designed to be multi-targettable with trunking and
concentrators.  Very high speed using 4-8 channel trunking.

FC-AL:  Mid-to-long range, low-to-high speed
Designed to be multi-targettable from day 1.  Very expensive.

iSCSI:  Mid-to-long range, high speed (with HBAs)
Designed to be multi-targettable from day 1.  Slow (no HBAs)
or semi-expensive ($1K+ HBAs), your choice.


-- 
Bryan J. Smith                | Sent from Yahoo Mail
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