Mailing List Archive

iscsitarget or targetcli?
Hi all,

I want to set up an iSCSI server (target in iSCSI terminology) running on
Gentoo.
Does anyone know which of the following 2 are better:
- sys-block/iscsitarget
- sys-block/targetcli

Both don't seem to have had an update for over 2 years, but targetcli seems to
be just the config-tool for whatever is in current kernels where, I think,
iscsitarget is a userspace daemon?

Many thanks,

Joost
Re: iscsitarget or targetcli? [ In reply to ]
On 29/01/15 10:25, J. Roeleveld wrote:
> Hi all,
>
> I want to set up an iSCSI server (target in iSCSI terminology) running on
> Gentoo.
> Does anyone know which of the following 2 are better:
> - sys-block/iscsitarget
> - sys-block/targetcli
>
> Both don't seem to have had an update for over 2 years, but targetcli seems to
> be just the config-tool for whatever is in current kernels where, I think,
> iscsitarget is a userspace daemon?
>
> Many thanks,
>
> Joost
>

I'd actually suggest using SCST
http://monklinux.blogspot.ie/2012/02/scst-configuration-how-to-using-gentoo.html

works very well and has a few extra niceties (dynamic resize
notification being one) that seem to be missing on other iscsi targets.
nice and easy syntax too
Re: iscsitarget or targetcli? [ In reply to ]
On Thursday, January 29, 2015 11:28:56 AM thegeezer wrote:
> On 29/01/15 10:25, J. Roeleveld wrote:
> > Hi all,
> >
> > I want to set up an iSCSI server (target in iSCSI terminology) running on
> > Gentoo.
> > Does anyone know which of the following 2 are better:
> > - sys-block/iscsitarget
> > - sys-block/targetcli
> >
> > Both don't seem to have had an update for over 2 years, but targetcli
> > seems to be just the config-tool for whatever is in current kernels
> > where, I think, iscsitarget is a userspace daemon?
> >
> > Many thanks,
> >
> > Joost
>
> I'd actually suggest using SCST
> http://monklinux.blogspot.ie/2012/02/scst-configuration-how-to-using-gentoo.
> html
>
> works very well and has a few extra niceties (dynamic resize
> notification being one) that seem to be missing on other iscsi targets.
> nice and easy syntax too



I managed to get dynamic resizing working when I did my first tests with
targetcli and the kernel-inbuild stuff:

Device Drivers --->
<M> Generic Target Core Mod (TCM) and ConfigFS Infrastructure --->
<M> TCM/IBLOCK Subsystem Plugin for Linux/BLOCK
<M> TCM/FILEIO Subsystem Plugin for Linux/VFS
<M> TCM/pSCSI Subsystem Plugin for Linux/SCSI
<M> Linux-iSCSI.org iSCSI Target Mode Stack

I only had to tell the iscsi-client to recheck the new size:
server : # resize filesystem
(Server was using targetcli with the kernel-inbuild stuff)

client : # iscsiadm -m node -T iqn....vm5... -R
client : # resize2fs /dev/sdb

What is the difference between the kernel-stuff (targetcli is only the config-
tool) and scst?

--
Joost
Re: iscsitarget or targetcli? [ In reply to ]
On 29/01/15 11:25, J. Roeleveld wrote:
> Hi all,
>
> I want to set up an iSCSI server (target in iSCSI terminology) running on
> Gentoo.
> Does anyone know which of the following 2 are better:
> - sys-block/iscsitarget
> - sys-block/targetcli
>
> Both don't seem to have had an update for over 2 years, but targetcli seems to
> be just the config-tool for whatever is in current kernels where, I think,
> iscsitarget is a userspace daemon?
>
> Many thanks,
>
> Joost
>

Hi,

sys-block/iscsitarget is composed of a kernel module and a userspace
daemon, both compiled and installed by the ebuild.

I would second the recommendation for SCST, which is actively developed
and in my experience is quite more stable and tends to recover better
from unexpected events than sys-block/iscsitarget (I have used both for
quite some time).

The only downside of SCST is that it requires a bit more work to
install, mainly because there is no ebuild for it; moreover, while it
can be built against and run on a stock kernel, it comes with a couple
of kernel patches which should be applied for optimal performance or are
needed fot specific features (e.g. the vdisk backend).

andrea
Re: iscsitarget or targetcli? [ In reply to ]
> What is the difference between the kernel-stuff (targetcli is only the config-
> tool) and scst?

http://scst.sourceforge.net/comparison.html

It was written by the SCST team, so it should be taken with a grain of
salt; it is nonetheless a useful overview of the alternatives out there.

andrea
Re: iscsitarget or targetcli? [ In reply to ]
On Thursday, January 29, 2015 02:18:13 PM Andrea Conti wrote:
> On 29/01/15 11:25, J. Roeleveld wrote:
> > Hi all,
> >
> > I want to set up an iSCSI server (target in iSCSI terminology) running on
> > Gentoo.
> > Does anyone know which of the following 2 are better:
> > - sys-block/iscsitarget
> > - sys-block/targetcli
> >
> > Both don't seem to have had an update for over 2 years, but targetcli
> > seems to be just the config-tool for whatever is in current kernels
> > where, I think, iscsitarget is a userspace daemon?
> >
> > Many thanks,
> >
> > Joost
>
> Hi,
>
> sys-block/iscsitarget is composed of a kernel module and a userspace
> daemon, both compiled and installed by the ebuild.

That's what I thought as well.

LIO / targetcli does seem to work and is implemented into the Linux kernel.

Is there anyone with actual experience with this together with Gentoo?
As I said, my initial quick tests showed that it works the way I want it to.

> I would second the recommendation for SCST, which is actively developed
> and in my experience is quite more stable and tends to recover better
> from unexpected events than sys-block/iscsitarget (I have used both for
> quite some time).
>
> The only downside of SCST is that it requires a bit more work to
> install, mainly because there is no ebuild for it; moreover, while it
> can be built against and run on a stock kernel, it comes with a couple
> of kernel patches which should be applied for optimal performance or are
> needed fot specific features (e.g. the vdisk backend).

I had a look at it, but the howtos I find are all based on older kernels
(2.6.x). I am currently using 3.14.27 for my testing as ZFS requires a kernel
older then 3.16.

I am reluctant to apply kernel patches, would prefer just some modules.
The documentation for installing SCST is scarcer then for LIO/targetcli. (The
latter has recent documentation on the Arch-linux site)

--
Joost
Re: iscsitarget or targetcli? [ In reply to ]
On Thursday, January 29, 2015 02:23:14 PM Andrea Conti wrote:
> > What is the difference between the kernel-stuff (targetcli is only the
> > config- tool) and scst?
>
> http://scst.sourceforge.net/comparison.html
>
> It was written by the SCST team, so it should be taken with a grain of
> salt; it is nonetheless a useful overview of the alternatives out there.
>
> andrea

I found a few comparisons like that. I would prefer one from an independent
source as both SCST and linux-iscsi.org (which seems to promote LIO/targetcli)
both paint the picture theirs is stable and the other one might be....

--
Joost