firewire disk support?

[Sean Bruno]

On Mon, 2009-02-02 at 19:51 +0000, Dieter wrote:

> How well does FreeBSD support firewire disks?
> Does hotplugging work properly?
> Does a bus reset endanger data?
> Can I turn the disk write cache on and off?
> Can I access SMART info?
> How fast are they?
> Specific firewire-to-sata bridges that are recommended?
> Specific bridges to avoid?
> Any known problems?
> 
> I have a couple of USB-to-*ATA bridges and they are slow,
> and they don't allow turning the disk's write cache off,
> or access to SMART info.  I know that firewire will be
> slower than esata, but the USB ones are really slow
> (10-15 MB/s) and not being able to turn the write cache
> on and off is a serious problem.


Excellent questions all.  Here is what I know:

FreeBSD firewire drives 400/800 do work just fine.

hotplug works much better now after a comitt to HEAD.(187993)
-- Some of which will be MFC'd to 7 soon

BUS_RESET's should behave fine, more data validation testing should be
done.

Caching and SMART do not work.  SBP doesn't pass through these commands
yet.  TODO

Disk speed on my Seagates in an FW800 enclosure do nicely ~40MB/s

My Firewire-SATA bridge:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817716028

Bridges/enclosures to avoid?  Unknown.

Known problems?

If a enclosure is 400/800, your BSD box is 400/800 capable and you
connect the 400 ports together, negotiation will fail
and attempt to use 800 speed on a 400 link.

I don't know if BSD is bootable from firewire either.

Hope this helps.

Sean