Re: iscsi (initiator) unstable

[Zafer Aydoğan <zafer%aydogan.de@localhost>]

FYI
I have traced it back to 6.99.15.
The problems disappear with 6.99.15.
The in-kernel iscsi code did not change between
6.99.15 till now, which means that
changes in the file system code in that
timeframe are very likely responsible
for the problems.

Z.


2014-07-06 15:20 GMT+02:00 Zafer Aydoğan <zafer%aydogan.de@localhost>:
> Hello List,
>
> I am new to the iscsi world and I am experiencing some difficulties getting
> iscsi to work reliably with NetBSD without knowing the core reason.
> I hope to figure it out and to fix the issues with this discussion.
>
> Status Quo:
> I have a server running 6.99.45 amd64 very smoothly and I have an
> iscsi target in
> the same network that I can connect to as described in iscsictl(8).
>
> After the logging in the sd0 disk device is present (or dk0 when
> formatted with gpt)
> and I can successfully newfs and mount the disk.
>
> Everything looks fine to this point.
>
> But the trouble starts as soon as I am writing data to the new storage.
>
> Copying files or creating a big sparse file (50 GB) with dd will stop
> the connection
> to the storage quite fast. Disk activity with small files will delay
> the interruption. The smaller the later.
> There is no obvious network problem. I can see packets flying around
> until they suddenly stop.
> When the connection stops, then the process is in state tstile (ps D).
>
> Everything else works fine. No crash or hang.
> I can cd to /storage but writes to the disk will not complete and
> wedge in tstile as well.
> Additionally, I can re-establish the iscsi session, which will give me
> a new disk device sd1, that I can mount and the story starts over.
> Running iscsid in debug mode does not reveal anything special.
>
> I tried different mount options (sync, log) because I thought
> that syncing data to the disk was the reason. But no luck.
>
> In my frustration I tried different file systems (lfs, ext2fs, v7fs),
> but all of them will stop working sooner or later, except v7fs, but
> thats due to the very low write-speed, I think.
>
> Any help is appreciated.
>
> Cheers,
> Zafer