Hi,
Andre Hedrick wrote:
> > > Please continue to think of TCP checksums as valid for a data transport,
> > > you data will be gone soon enough.
> > >
> > > Initiator == Controller
> > > Target == Disk
> > > iSCSI == cable or ribbon
> > >
> > > Please turn off the CRC on your disk drive and see if you still have data.
> >
> > This maybe works as PR, but otherwise it's crap.
>
> So, please turn off the CRC's in your onboard storage today and see how
> long it lasts.
If you want to compare apples with apples, you should rather tell me how
I turn off the checksumming of my nic.
> > With a network protocol you have multiple possibilities to increase the
> > reliability. The lower you do it in the network layer the easier is it
> > to put it into hardware and to optimize it and the more generically it's
> > usable. Doing it in the protocol is only the last resort. The iSCSI
> > protocol is a nice protocol - if you ignore all the crap the hardware
> > vendors put in (that stuff only makes sense if you want to produce ultra
> > cheap hardware).
>
> I will be happy to see everyone turn off the CRC's on the data and headers
> on their products or the open sources ones which fail to follow the rules.
> I am well away of everyones contempt for standards.
You know RFC2119?
bye, Roman
On Wed, 2003-01-08 at 00:04, Roman Zippel wrote:
> If you want to compare apples with apples, you should rather tell me how
> I turn off the checksumming of my nic.
For some cards you can do this. For instructive information on the effects
look at the saga of sunos 3.x and NFS over wans. Old SunOS turned off UDP
checksums for NFS. It provided an adequate demonstration that UDP checksums
for NFS are needed. Sun of course addressed this design error long long
ago.
On Wed, Jan 08, 2003 at 01:43:01AM +0000, Alan Cox wrote:
> On Wed, 2003-01-08 at 00:04, Roman Zippel wrote:
> > If you want to compare apples with apples, you should rather tell me how
> > I turn off the checksumming of my nic.
>
> For some cards you can do this. For instructive information on the effects
> look at the saga of sunos 3.x and NFS over wans. Old SunOS turned off UDP
> checksums for NFS. It provided an adequate demonstration that UDP checksums
> for NFS are needed. Sun of course addressed this design error long long
> ago.
BK has a pretty lame checksum but good enough to catch a lot of errors
and we still catch 'em. Software, hardware, network, whatever, they
happen all the time.
--
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Larry McVoy lm at bitmover.com http://www.bitmover.com/lm