As I惴 an inexperient about iscsi, I would like to ask some few questions:
Does iscsi target and iniciator work well in the linux fedora platform ?
Which of the HBA (Qlogic愀 for an example) works fine with fedora and
iscsi stuff ?
All of this because I working on a storage project, and I would like to
create my own
storage system....Thank愀 in advance...
--
Marcos G. M. Santos
SysAdmin - DIGILAB S.A.
Tel: 55 48 3234 4041
www.digilab.com.br
Yes.
> Which of the HBA (Qlogic´s for an example) works fine with fedora and
> iscsi stuff ?
Well, the QLA4xxx works OK, but you need to use the QLogic tools which are
woefully out of date. Once you have it setup it works nicely.
I have been studing the PCI Express for higher volume information
throughput. And the iscsi Qlogic´s HBA model
is the QLE4xxx, instead of QLA4xxx. Do you have any expirience about it
? Would this work as well as the QLA4xxx for Fedora environment ?
Thanks!
It is the same chipset. Just a different form-factor.
> ? Would this work as well as the QLA4xxx for Fedora environment ?
Yes. The qla4xxx driver supports both form-factors and both port-options (dual or single port).
So, do you think that I´m in the right direction, when I say that I´m
going to create my own
repository with some proprietary hardware and free software? Or it could
be a bad trip...
Thank´s!
What is it that you are intending to do? If you are just looking to use iSCSI
I would recommend you first play with the Open-ISCSI initator (I presume you
already have an iSCSI target?). If you want no CPU load when doing iSCSI, then
the hardware HBA's are the choice.
In my inicial goal, I would like to have a linux box as a target and
Gbit NIC cards for acessing
it. Putting four 500GB SATA II HD in a RAID10 assemble for reliability,
creating a 1TB redundant storage...
The redundancy was nice with mdtools, but the performance with the
open-iscsi was not good...
Speaking about the CPU load, as the storage will be a dedicated file
server, the whole CPU will
be for file sharing and storage...
So that´s why I am asking about the QLogic HBA´s...
Are your test results available? I would be curious to see what made the
Microsoft Software Initiator (v2.0?) faster than the Open-ISCSI one.
Both of them are software based so there shouldn't be a big difference
in the speed of them.
>
> In my inicial goal, I would like to have a linux box as a target and
> Gbit NIC cards for acessing
> it. Putting four 500GB SATA II HD in a RAID10 assemble for reliability,
> creating a 1TB redundant storage...
> The redundancy was nice with mdtools, but the performance with the
> open-iscsi was not good...
>
> Speaking about the CPU load, as the storage will be a dedicated file
> server, the whole CPU will
> be for file sharing and storage...
Right. That is unavoidable on the target side. I was thinking on the client
(initiator) where the data-gram check-summing would be offloaded to the HBA.
There is nothing you can do about the target side to off-load the check-summing
(well, not yet).
>
> So that愀 why I am asking about the QLogic HBA愀...
If you go with the HBA, you will get the no CPU usage on your initiator (good)
and there won't be any extra overhead in unmarshalling TCP->iSCSI->SCSI. I don't
know how "much" faster it would be in doing I/O. If you go this route I would
advise on buying it with a return-back policy so that you can test it against the
software based initiators and if the I/O benchmarks don't make it look that sexy -
you can return the HBA.
Also be aware that the switches (or the lack of them) between your target and
initiator are important.
I do not think I have ever heard that result before. For fedora target
do you mean, scsi-target-utils rpm that comes with fedora or is it a
IET/iscsi-target based rpm?
What list? This one or one of the fedora lists?