Accessing SCSI-Devices >2TB

[Raphael H. Becker]

On Sat, Jun 11, 2005 at 09:54:40PM -0600, Kenneth D. Merry wrote:
> On Sun, Jun 12, 2005 at 00:25:08 +0200, Raphael H. Becker wrote:
> > The support told me, SuSE Linux is known to work with >2TB in one device,
> > means they might have some patches to work around. I will try a SuSE
> > live system next days just to get sure it works. But the System won't
> > be SuSE in future.
> 
> It would be interesting to see whether that works.  That would help narrow
> down the problem slightly.

I had some things to seek out last days.
First, it doesn't work with SuSE 9.2 Live system! 

See http://rabe.uugrn.org/temp/FreeBSD/bigraid/dmesg.suse92_onebig.txt

[...] 
scsi1 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.36
        <Adaptec 3960D Ultra160 SCSI adapter>
        aic7899: Ultra160 Wide Channel B, SCSI Id=7, 32/253 SCBs

(scsi1:A:0): 160.000MB/s transfers (80.000MHz DT, offset 127, 16bit)
  Vendor: IFT       Model: A12U-G2421        Rev: 342D
  Type:   Direct-Access                      ANSI SCSI revision: 03
scsi1:A:0:0: Tagged Queuing enabled.  Depth 32
[...]
sdb : very big device. try to use READ CAPACITY(16).
sdb : READ CAPACITY(16) failed.
sdb : status=0, message=00, host=5, driver=00 
sdb : use 0xffffffff as device size
SCSI device sdb: 4294967296 512-byte hdwr sectors (2199023 MB)
SCSI device sdb: drive cache: write back
 sdb:<6>tg3.c:v3.9 (August 30, 2004)
ACPI: PCI interrupt 0000:03:06.0[A] -> GSI 7 (level, low) -> IRQ 7
 unknown partition table
Attached scsi disk sdb at scsi1, channel 0, id 0, lun 0
[...]

Some mail with the RAID's distributor and his manufacturers support I
got the information in Linux(!) the support depends on the scsi
controllers (kernel)driver and (just?) LSI cards are know to work with
LBA64 under linux this time.

So the manufacturers position is "it works if you support LBA64 on the host".  

> > # camcontrol debug -c 1:0
> > # camcontrol rescan 1
> > Re-scan of bus 1 was successful
> > 
> > in /var/log/messages:
> 
> Hmm, well, you're not going to see the problem CDB that way, because the
> probe has already happened.  To see it, you either need to compile in the
> debugging flags, or do the following:
> 
> - unplug the cable from the machine to the RAID array
> - camcontrol rescan 1
> - plug the cable back in
> - camcontrol rescan 1

Did:
  - remote disconnected the RAID via internal controller
  - camcontrol rescan 1
  - camcontrol devlist (RAID disappeared)
  - remote attach the RAID
  - turn on debugging
  - camcontrol rescan 1 (needed some time)
  - camcontrol devlist (RAID reemerged)
See http://rabe.uugrn.org/temp/FreeBSD/bigraid/freebsd54_camdebug_rescan.txt

 
> It's either the RAID box or the ahc driver from what I can see at this
> point.  See below.
[...]
> So this pretty much means it is the 16 byte read capacity that is
> triggering the problem.
> 
> The question is, is this problem on the RAID box or in the ahc driver?  I
> would lean towards saying the RAID box has the issue, but Justin (CCed) may
> be able to give a little more insight.

According to the manufacturer it just depends on the controllers LBA64 support.


Regards
Raphael Becker