Re: iSCSI: NetBSD-9 target, Linux initiator

[Chavdar Ivanov <ci4ic4%gmail.com@localhost>]

On Fri, 21 Feb 2020 at 18:46, BERTRAND Joel <joel.bertrand%systella.fr@localhost> wrote:
>
> Michael van Elst a écrit :
> > joel.bertrand%systella.fr@localhost (BERTRAND Joel) writes:
> >
> >> If I understand... Error is triggered by test
> >> /usr/src/netbsd-9/src/external/bsd/iscsi/lib/../dist/src/lib/disk.c line
> >> 1405 when initiator sends data greater than 1MB.
> >
> >> Why this limitation ?
> >
> > Apparently to avoid allocating an arbitrary sized buffer.
>
>         Yes, but why not allocate for example a 4MB buffer ?
>
> > In my experience the iscsi target (and the userland iscsi initiator)
> > are pretty limited and somewhat broken. I suggest you use the
> > iscsi target from pkgsrc (net/istgt). Much better, faster and more
> > compatible.

Years ago, perhaps around NetBSD v.5 or 6, I tried the built-in iSCSI
target and found the same - it was, shall we say, rather flaky. I then
started using net/istgt, it worked for me as well.

Lately, since I enabled it on one of my systems running -current of
the day with 2-3 updates a week, I've found the built-in target to be
reasonably ok, at least with initiators running on various Windows
versions; I haven't had any reason to try it with other initiators so
far. As I mentioned before, my extents are either /dev/rdkxx from a
GPT disk, or a ZFS zvols. I do get
src/external/bsd/iscsi/lib/../dist/src/lib/disk.c:1364: ***ERROR***
UNKNOWN OPCODE 0xa1 (or 0xdf or 0x9e), but they don't seem to affect
the operation. Performancewise, things are not so good - i have a
FreeNAS 11.3 on the same gigabit switch, from the same Windows 10
initiator I get 2-4 times better figures (measured by
CrystalDiskMark), even if the FreeNAS server is only a guest on a
XCP-NG host, whereas the NetBSD machine is physicall; both with
gigabit interfaces.

I should try again net/istgt just to check the performance figures.


>
>         Same configuration files or not ?

Definitely not...

>
>         Best regards,
>
>         JKB



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