Re: SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14)

Re: SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14)

[Denny Page]

Ray,

The problem has to do with the speed negotiation that occurs on  
driver initialization.

That I know of, there are 2 ways to address the problem.

For kernel 2.6.17 (and later), you can go into the Adaptec scsi bios  
and explicitly limit the transfer speed for the target device to 160  
MB/s.

Alternatively, for kernel 2.6.16 (and later), you can add the  
following to your boot init file:

   # Fix scsi speed negotiation on tape drive
   SYS_TAPE=/sys/class/spi_transport/target0:0:3
   echo "12.5" > $SYS_TAPE/min_period
   echo "1"    > $SYS_TAPE/revalidate

[Remember to change the SYS_TAPE variable to match your target device]

You will know that you've done it correctly when you see 160MB/s as  
the value of User/Goal/Curr for your target in /proc/scsi/aic79xx/*.

In my case, it's still unclear to me whether or not the problem is  
the AIC79xx, the HP LTO drive, or the scsi driver.

Hope this helps.

Denny



On Nov 23, 2006, at 11:40 , Raymond Scholz wrote:

> Hello Denny,
>
> sorry for bothering you with this but I spent the whole day searching
> the net for the reason why our SCSI LTO-2 tape suddenly dropped
> performance down to 2MB/s after upgrading the Linux kernel.
>
> Your description and hardware comes close to the behaviour we  
> observed:
>
> http://www.spinics.net/lists/linux-scsi/msg06003.html
> http://thread.gmane.org/gmane.linux.scsi/22010/focus=22021
>
> Did you receive any response or (even better) found a better solution
> than downgrading the kernel?
>
> Cheers, Ray
> -- 
> Raymond Scholz - rscholz@zonix.de - GnuPG/PGP - http://www.zonix.de/
>

Re: SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14)

[Alexander Jolk]

Denny Page wrote:
> The problem has to do with the speed negotiation that occurs on  driver 
> initialization.
> 
> That I know of, there are 2 ways to address the problem.
> 
> For kernel 2.6.17 (and later), you can go into the Adaptec scsi bios  
> and explicitly limit the transfer speed for the target device to 160  MB/s.
> 
> Alternatively, for kernel 2.6.16 (and later), you can add the  following 
> to your boot init file:
> 
>   # Fix scsi speed negotiation on tape drive
>   SYS_TAPE=/sys/class/spi_transport/target0:0:3
>   echo "12.5" > $SYS_TAPE/min_period
>   echo "1"    > $SYS_TAPE/revalidate
> 
> [Remember to change the SYS_TAPE variable to match your target device]
> 
> You will know that you've done it correctly when you see 160MB/s as  the 
> value of User/Goal/Curr for your target in /proc/scsi/aic79xx/*.
> 
> In my case, it's still unclear to me whether or not the problem is  the 
> AIC79xx, the HP LTO drive, or the scsi driver.

I have successfully used your procedure in order to get an HP LTO-3 
driver to work that's attached to an LSI/Fusion/MPT controller.  That 
would seem to point to the drive or the scsi driver rather than the 
controller.

Alex


-- 
Alexander Jolk         /         BUF Compagnie
tel +33-1 42 68 18 28 /  fax +33-1 42 68 18 29

Re: SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14)

[Raymond Scholz]

· Alexander Jolk <alexj@buf.com> wrote:

> I have successfully used your procedure in order to get an HP LTO-3 
> driver to work that's attached to an LSI/Fusion/MPT controller.  That
> would seem to point to the drive or the scsi driver rather than the
> controller.

My initial (private) mail didn't contain any specific hardware
versions.  So if it helps to track down the reason for the negotiation
problem, here they are:

LTO tape:

Host: scsi2 Channel: 00 Id: 06 Lun: 00
  Vendor: CERTANCE Model: ULTRIUM 2        Rev: 1823
  Type:   Sequential-Access                ANSI SCSI revision: 03

Controller:

Adaptec AIC79xx driver version: 1.3.11
Adaptec AIC7902 Ultra320 SCSI adapter
aic7902: Ultra320 Wide Channel B, SCSI Id=7, PCI 33 or 66Mhz, 512 SCBs

Raymond
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Re: SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14)

[Alexander Jolk]

Raymond Scholz wrote:
> My initial (private) mail didn't contain any specific hardware
> versions.  So if it helps to track down the reason for the negotiation
> problem, here they are:
> 
> LTO tape:
> 
> Host: scsi2 Channel: 00 Id: 06 Lun: 00
>   Vendor: CERTANCE Model: ULTRIUM 2        Rev: 1823
>   Type:   Sequential-Access                ANSI SCSI revision: 03
> 
> Controller:
> 
> Adaptec AIC79xx driver version: 1.3.11
> Adaptec AIC7902 Ultra320 SCSI adapter
> aic7902: Ultra320 Wide Channel B, SCSI Id=7, PCI 33 or 66Mhz, 512 SCBs

Here are mine:
Host: scsi1 Channel: 00 Id: 01 Lun: 00
   Vendor: HP       Model: Ultrium 3-SCSI   Rev: G25H
   Type:   Sequential-Access                ANSI SCSI revision: 03

Fusion MPT SPI Host driver 3.04.02
ioc1: 53C1030: Capabilities={Initiator,Target}
scsi1 : ioc1: LSI53C1030, FwRev=01032700h, Ports=1, MaxQ=255, IRQ=19
scsi 1:0:1:0: Sequential-Access HP       Ultrium 3-SCSI   G25H PQ: 0 ANSI: 3
  target1:0:1: Beginning Domain Validation
  target1:0:1: Ending Domain Validation
  target1:0:1: FAST-160 WIDE SCSI 320.0 MB/s DT IU RTI PCOMP (6.25 ns, 
offset 64)

Alex


-- 
Alexander Jolk         /         BUF Compagnie
tel +33-1 42 68 18 28 /  fax +33-1 42 68 18 29