[Open-FCoE] Actual data transfer (FCoE)

hansraj Jadhav hansrajpict at gmail.com
Wed Jan 21 10:42:30 UTC 2009


Hi Joe,

Im creating LUNS on the target.
+ This is the command i use:

*dd if=/dev/null of=/target/mydisk bs=1M count=100 2>/dev/null

echo "open mydisk /target/mydisk" > /proc/scsi_tgt/vdisk/vdisk

*+ It shows the size of mydisk as zero.

Name              *Size(MB)*    Block size  Options         File name
mydisk            * 0  *               512
/target/mydisk

Is this the problem?

@Robert
The* fdisk -l* on the inititator shows only the physical disks attached.
It does not show any other disks.
I can see the Luns when i do a "cat /proc/scsi/scsi"  &
I can also see new devices if i do " ls /dev/s* ".

+ Please find the text file below.

Regards
Hansraj




On Wed, Jan 21, 2009 at 12:44 AM, Joe Eykholt <jre at nuovasystems.com> wrote:

> Robert Love wrote:
> > On Tue, 2009-01-20 at 21:37 +0530, hansraj Jadhav wrote:
> >> Hi Joe,
> >>
> >> Thanks for your quick response.
> >>
> >> I tried out the instructions mentioned.
> >> + I checked the pause and set the tx and the rx 'on' and autoneg ' off
> '.
> >> + I also tried
> >> dd if=/dev/sdXX of=/dev/null count=100 iflag=direct
> >>
> >> dd: reading `/dev/sdc': *Input/output error*
> >> 0+0 records in
> >> 0+0 records out
> >> 0 bytes (0 B) copied, 0.00198219 seconds, 0.0 kB/s
> >>
> >> + Please find a text file, captured using tshark.
> >>
> > Unfortunately I don't get the attachment. I have two accounts subscribed
> > to this list and I don't get it on either.
> >
> > What does 'fdisk -l' show on the initiator side? If you're seeing dev
> nodes on the initiator you must be connecting to your target and SCSI must
> be talking to the LUNs. I'm curious if
> they're showing any capacity though, fdisk should answer that.
>
> Robert, you guessed the problem I think.  The sense
> says the LBA is out of range, so LUN 0 has no capacity.  This isn't too
> unusual.
> Hansraj, maybe you used another LUN number for the disk, but in any case,
> the problem
> is on the target side.
>
> Here's the end of your trace with my comments:
>
>  3  11.083730     01.01.01 -> 01.02.00     FCP SCSI: Read(10) LUN: 0x00
> (LBA: 0x00000000,
> Len: 1)
>
> 0000  0e fc 00 01 02 00 0e fc 00 01 01 01 89 06 00 00   ................
> 0010  00 00 00 00 00 00 00 00 00 00 00 2e 06 01 02 00   ................
> 0020  00 01 01 01 08 29 00 00 00 00 00 00 01 2f ff ff   .....)......./..
> 0030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02   ................
> 0040  28 00 00 00 00 00 00 00 01 00 00 00 00 00 00 00   (...............
> 0050  00 00 02 00 08 67 54 bf 42 00 00 00               .....gT.B...
>
>  4  11.084619     01.02.00 -> 01.01.01     FCP SCSI: Response LUN: 0x00
> (Read(10)) (Check
> Condition) LUN:0x00
>
> 0000  0e fc 00 01 01 01 0e fc 00 01 02 00 89 06 00 00   ................
> 0010  00 00 00 00 00 00 00 00 00 00 00 2e 07 01 01 01   ................
> 0020  00 01 02 00 08 98 00 00 66 00 00 00 01 2f 4b e0   ........f..../K.
> 0030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 0a 02   ................
> #                                         sense start 70 key 5
> 0040  00 00 02 00 00 00 00 1a 00 00 00 00 70 00 05 00   ............p...
> #     4  5  6  7 addl len a    additional sense code 21
> #                 8  9  10 11 12 13 14 15 16 17 18 19
> 0050  00 00 00 0a 00 00 00 00 21 00 00 00 00 00 00 00   ........!.......
> #      2  3  4  5  6  7  8  9 10 11 12 13 14 15
> 0060  00 00 00 00 00 00 00 02 00 94 91 51 42 00 00 00   ...........QB...
>
>
> >> Regards
> >> Hansraj
> >>
> >>
> >>
> >> ---------- Forwarded message ----------
> >> From: Joe Eykholt <jre at nuovasystems.com>
> >> Date: Tue, Jan 20, 2009 at 3:00 PM
> >> Subject: Re: [Open-FCoE] Actual data transfer (FCoE)
> >> To: hansraj Jadhav <hansrajpict at gmail.com>
> >> Cc: devel at open-fcoe.org
> >>
> >>
> >> hansraj Jadhav wrote:
> >>
> >>> Hi all,
> >>>
> >>> + Im using the Open FCoE initiator.
> >>>   Im creating virtual LUNS on the target. and i m also able to see
> these
> >>> luns
> >>>  on the initiator when i do a
> >>>  cat /proc/scsi/scsi.
> >>>
> >>> + Im stuck here, how do i see an actual data transfer from the
> initiator to
> >>> the target.
> >>> + I also tried doing mkfs on the Luns discovered, but it failed after
> some
> >>> time.
> >>>
> >>>
> >>>
> >>> Thanks,
> >>> Hansraj
> >>>
> >>>
> >> Hi Hansraj,
> >>
> >> First, be sure you have Ethernet link pause autonegotiated or
> >> turned on for both nodes and a point-to-point connection
> >> with no switch in the middle unless it supports lossless behavior
> >> (very few do).  You can check pause with 'ethtool -a ethX'.
> >> It should show 'tx on rx on' for both sides.  If not, do
> >> 'ethtool -A ethX auto off tx on rx on'  If your NICs do not support
> >> pause, you could very well have data transfer problems.  Although
> >> SCSI will retry the operations, if the data overruns, it could
> >> overrun on the retry attempts indefinitely.
> >>
> >> Second, the drives should work just like any other disk device.
> >> Try doing reads with dd on the disks.  If you do
> >> 'dd if=/dev/sdXX of=/dev/null count=100 iflag=direct' you will
> >> get 100, 512-byte reads.  The 'iflag=direct' bypasses the buffer
> >> cache to make sure they are real I/Os after the first time.
> >> Of course, substitute your actual drive for /dev/sdXX.
> >>
> >> You can switch this around to do writes and test for data integrity.
> >> I make a random file and then copy it to the drive and
> >> read it back like this:
> >>        dd bs=64k count=100 if=/dev/urandom of=/tmp/patt
> >>        dd bs=64k if=/tmp/patt of=/dev/sdXX oflag=direct
> >>        dd bs=64k if=/dev/sdXX of=/tmp/read iflag=direct count=100
> >>        cmp /tmp/patt /tmp/read
> >>
> >> Since you had failures, I'm guessing the pause
> >> issue is the problem.   Let me know how it goes.  If you still
> >> have problems, you could send a small packet trace during the
> >> failures gathered with:
> >>
> >> tcpdump -i ethX -w trace.cap -s 300 -c 200 ether proto 0x8906
> >>
> >>        Joe
> >>
> >>
> >>
> >>
> >>
> >> _______________________________________________
> >> devel mailing list
> >> devel at open-fcoe.org
> >> http://www.open-fcoe.org/mailman/listinfo/devel
> >
>
>


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