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

[Robert Snively <rsnively@Brocade.COM>]

Julian,

 

The stated environment was a diskless home system with disks remote.

 

Home system means broadband attachment at less than 1.5 Mb/sec from

the home to the remote iSCSI device, so it really doesn't matter how

fast your local connection is (10 Mb/s or 100 Mb/s, you only get 1.5 Mb/s max)

 

Been there, done that, it is not so hot, unless system, swap, and

program are local, meaning not diskless.  Dataless with NFS works

okay, because all the operational functions run locally and only file

access runs remotely, and that does not require iSCSI (and in fact works better

without iSCSI for comparable technology).

 

The stated environment was legacy, which means there is no administrative

tool or specialized file system to allow the use of shared remote storage.

 

I absolutely agree that native SCSI disks will perform better than IDE disks attached

via local or remote iSCSI.

 

Bob

-----Original Message-----
From: Julian Satran [mailto:Julian_Satran@il.ibm.com]
Sent: Monday, April 14, 2003 4:36 PM
To: Robert Snively
Cc: ips@ece.cmu.edu; owner-ips@ece.cmu.edu; 'Russell Lewis'
Subject: RE: Are there any coming iSCSI HBAs? Preferably at 100Mb speed?

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?
>
>