Data authentication for geli(8) committed to HEAD.

[Daniel O'Connor]

On Friday 09 June 2006 03:11, Ulrich Spoerlein wrote:
> I have an external HDD that I initially attached via Firewire, but I've
> since switched to USB, as our firewire subsystem is less than rock

Interesting. I find the reverse :)
Then again I started using Firewire in 4.x where USB2.0 didn't exist and the 
USB 1 code was kind of dodgy.

> The question really is, are 512 byte disk writes considered to be some
> kind of "atomic" as it is the smallest disk block size? What does the
> ATA subsystem do with writes of 4096? Are they completed atomically too,
> or not?

I think that in reality with a modern high capacity disk you don't get atomic 
writes at all because they all re-write whole tracks.

Yes this violates the assumption soft updates makes, I believe the only way 
around it is to buy SCSI drives (not because they're SCSI per se, but because 
they're smaller capacity so they don't do this)

-- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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