RE: Are there any coming iSCSI HBAs? Preferably at 100Mb speed?

[Andre Hedrick <andre@linux-ide.org>]

Julo,

Have you ever attempted to virtualize a soft raid device to iSCSI?
We are finding out that native ATA using a fastpath with channel io
balancing romps even expensive SCSI drives.  The new SATA 1.0 with SATA
2.0 HBA's effective running SAS with first party dma, just blisters
anything out there today.

I have actually gotten one SATA HBA and drive to burst to wire speeds.
Smoking the bus with writes approaching 144MB/sec (burst) and nil on the
CPU overhead blew me away.  Given much of todays PATA is just a PHY bolted
on the bottom, using such a HBA with dongles+pata can not be far behind.

The numbers I posted were based on a 6 drive 5400 rpm pata's with sata
dongles.

Cheers,

Andre Hedrick
LAD Storage Consulting Group

On Tue, 15 Apr 2003, Julian Satran wrote:

> Bob,
> 
> I wonder if your opinion is based on real experience or prejudice.
> Our measurements indicate that an inexpensive box with SCSI disks performs 
> BETTER than an IDE (typical) desktop drive
> using iSCSI over a 100MB/s connection (widely available for home use) - 
> and that includes paging (usually marginal) and all the rest.
> 
>         Julo
> 
> 
> 
> Robert Snively <rsnively@Brocade.COM> 
> Sent by: owner-ips@ece.cmu.edu
> 14/04/03 18:06
> 
> To
> Russell Lewis/Tucson/IBM@IBMUS, ips@ece.cmu.edu
> cc
> 
> Subject
> RE: Are there any coming iSCSI HBAs?  Preferably at 100Mb speed?
> 
> 
> 
> 
> 
> 
> My experience with diskless workstations is that 
> they are limited by paging activity and background 
> updating to really unacceptable performance, even in 
> simple word-processing programs like frame maker 
> doing medium sized books, and even on a local 10 Mb/s 
> network. 
> You are far better off running a workstation with 
> a local disk for system and swap, but running 
> dataless.  NFS or comparable networking programs 
> run fine for that.  The local caching of the files 
> on disk and in memory assure adequate performance, while 
> the maintenance of your data remotely assures 
> appropriate centralized data management and backup. 
> Remember too, that it is a rare broadband connection 
> that gives you anything approaching 100 Mb/s.  A T1 DSL link 
> is specified at 1.54 Mb/s, and it is the fastest of the 
> common broadband links. 
> In addition, there is nothing more frustrating than being 
> unable to operate because your link is down or severely 
> congested, something that happens far more often than the 
> unavailability of a local disk. 
> My view?  iSCSI is not an appropriate protocol for home 
> networking data access.  Use your IDE or SATA drive locally 
> for boot, swap, system, and any hot programs and use 
> NFS or other remote file access program against a remote 
> server for data and other programs. 
> Bob Snively 
> 408-333-8135 
> rsnively@brocade.com 
> > -----Original Message----- 
> > From: Russell Lewis [mailto:russelll@us.ibm.com] 
> > Sent: Friday, April 11, 2003 9:25 AM 
> > To: ips@ece.cmu.edu 
> > Subject: Are there any coming iSCSI HBAs? Preferably at 100Mb speed? 
> > 
> > 
> > 
> > 
> > 
> > 
> > Does anybody know of any current or coming iSCSI HBAs which 
> > show up (to the 
> > BIOS) as ordinary SCSI adapters?  I'd like to drop such an HBA into a 
> > legacy computer and run a totally diskless workstation at home. 
> > 
> > However, since it will be a home computer, I'm willing to 
> > operate at 100Mb 
> > speed - I'm willing to eat the performance hit.  It seems to me that 
> > somebody could make an iSCSI HBA with a 100Mb interface and make it 
> > affordable for the home user (say, $50-$100).  Anybody know 
> > of such plans? 
> > 
> > 
>