SCSI tape (Re: scsi negotiation problem on aic79xx (39320A) in 2.6.14)
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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
Quoted 18 lines · Raymond Scholz
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=22021Did you receive any response or (even better) found a better solution than downgrading the kernel?
Cheers, Ray
Signature · 1 line
Raymond Scholz - [email protected] - GnuPG/PGP - http://www.zonix.de/
Quoted 13 lines · Denny Page
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
Quoted 5 lines
[Remember to change the
SYS_TAPEvariable 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
Signature · 2 lines
Alexander Jolk / BUF Compagnie tel +33-1 42 68 18 28 / fax +33-1 42 68 18 29
Quoted 4 lines · · Alexander Jolk
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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Quoted 10 lines · Raymond Scholz
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
Quoted 5 lines
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
Signature · 2 lines
Alexander Jolk / BUF Compagnie tel +33-1 42 68 18 28 / fax +33-1 42 68 18 29