rp8420: scsictl shows bus speed at 160 MB/s and Negotiated Target Values at 40 MB/s

[Rudolf Fischer]

Hi all,

we are facing a problem regarding internal SCSI busses with a HP rp8420 with only one cell. If I do a "scsictl -c get_bus_parm" the bus limits and bus parms speed all at 160 MB/s, where "scsictl -c get_target_parm" shows the target limit at 160 MB/s and the negotiated target value at 40 MB/s. This is also true for the second internal SCSI drive. Both internal SCSI buses are negotiated at 40 MB/s.

We´ve checked the internal SCSI connections and it seems all ok. A internal SCSI disk from a rp3440 which runs in this server at a negotiated target speed of 160 MB/s is running in the rp8420 also at 40 MB/s so it couldn´t for me a problem with disk. Disk tests resulted in read speed at about 70 MB/s on rp3440 and at about 30 MB/s on rp8420.

I´ve appended the outputs from scsictl, ioscan and service menu. Has anyone an idea how to get the connected internal disks working at 160 MB/s?

Best regards,

Rudolf Fischer

##################################################################################

# scsictl -c get_bus_parm /dev/rdsk/c0t6d0

BUS LIMITS
----------
flags:          0x0
width:          16 bits (8 = Narrow; 16 = Wide)
req/ack offset: 62
xfer rate:      80000000
SPEED:          160 MB/s (Ultra160 Wide)

BUS PARMS
---------
flags:          0x0
width:          16 bits (8 = Narrow; 16 = Wide)
req/ack offset: 62
xfer rate:      80000000
SPEED:          160 MB/s (Ultra160 Wide)

# scsictl -c get_target_parm /dev/rdsk/c0t6d0

TARGET LIMITS
-------------
flags:          0x0
width:          16 bits (8 = Narrow; 16 = Wide)
req/ack offset: 62
xfer rate:      80000000
SPEED:          160 MB/s (Ultra160 Wide)

NEGOTIATED TARGET VALUES
------------------------
flags:          0x0
width:          16 bits (8 = Narrow; 16 = Wide)
req/ack offset: 31
xfer rate:      20000000
SPEED:          40 MB/s (Ultra Wide)

# ioscan -fnkCext_bus
Class     I  H/W Path        Driver   S/W State   H/W Type     Description
===========================================================================
ext_bus   0  0/0/0/2/0       c8xx     CLAIMED     INTERFACE    SCSI C1010 UltraWide Single-Ended
ext_bus   1  0/0/0/2/1       c8xx     CLAIMED     INTERFACE    SCSI C1010 UltraWide Single-Ended
ext_bus   2  0/0/0/3/0       c8xx     CLAIMED     INTERFACE    SCSI C1010 UltraWide Single-Ended
ext_bus   3  0/0/0/3/1       c8xx     CLAIMED     INTERFACE    SCSI C1010 Ultra160 Wide LVD

# ioscan -fnkCdisk
Class     I  H/W Path        Driver   S/W State   H/W Type     Description
===========================================================================
disk      0  0/0/0/2/0.6.0   sdisk    CLAIMED     DEVICE       HP 73.4GST373453LC
                            /dev/dsk/c0t6d0   /dev/rdsk/c0t6d0
disk      1  0/0/0/2/1.2.0   sdisk    CLAIMED     DEVICE       _NEC    DVD_RW ND-3540A
                            /dev/dsk/c1t2d0   /dev/rdsk/c1t2d0
disk      2  0/0/0/3/0.6.0   sdisk    CLAIMED     DEVICE       HP 73.4GST373453LC
                            /dev/dsk/c2t6d0   /dev/rdsk/c2t6d0

Service Menu: Enter command > scsi 0

Cell: 0
 =========
   Path (dec)         Initiator ID  SCSI Rate  Bus Width
   -----------------  ------------  ---------  ---------
   0/0/0/2/0               7           MAX        MAX
   0/0/0/2/1               7           MAX        MAX
   0/0/0/3/0               7           MAX        MAX
   0/0/0/3/1               7           MAX        MAX

[Torsten.]

It will be hard to find a similar system to compare ...

However, I would try

# scsictl -c domain_val   /dev/rdsk/c0t6d0

# scsictl -c get_target_parm /dev/rdsk/c0t6d0

[Rudolf Fischer]

Sorry Torsten,

scsictl -c domain_val did not solve the problem. Negotiated Target Value always at 40 MB/s.

I forgot, PHKL_36521 SCSI Ultra160 Cumulative Patch is installed.

[Torsten.]

It's all too long ago ...

Look at this:

# ioscan -fnkCext_bus
Class     I  H/W Path        Driver   S/W State   H/W Type     Description
===========================================================================
ext_bus   0  0/0/0/2/0       c8xx     CLAIMED     INTERFACE    SCSI C1010 UltraWide Single-Ended
ext_bus   1  0/0/0/2/1       c8xx     CLAIMED     INTERFACE    SCSI C1010 UltraWide Single-Ended
ext_bus   2  0/0/0/3/0       c8xx     CLAIMED     INTERFACE    SCSI C1010 UltraWide Single-Ended
ext_bus   3  0/0/0/3/1       c8xx     CLAIMED     INTERFACE    SCSI C1010 Ultra160 Wide LVD

Your problem disk is connected to the first, the second disk is connected to the 4th controller. This is Ultra160, the first Single-ended only.

 Both are part of the core I/O.

Hmm... maybe this is really the max of this bus?

This is interesting:

https://community.hpe.com/t5/System-Administration/ioscan-and-scsi-what-does-it-mean/td-p/4849985

[Rudolf Fischer]

Hi Thorsten,

Thank you for your reply.

You are right with the first disk. The second disk is connected to controller 0/0/0/3/0 which is the third controller. The rp8420 has four slots for internal disks. The physical location of the disks are

Slot 0 Drive 0/0/0/2/0.6.0 Upper left

Slot 1 Drive 0/0/0/3/0.6.0 Upper right

Slot 2 Drive 1/0/0/2/0.6.0 Bottom left

Slot 3 Drive 1/0/0/3/0.6.0 Bottom right

The disks are working in slot 0 and slot 1 and the disks in slot 2 and 3 should only works if a server expansion unit is installed. We don´t have a SEU installed.

I think the crucial question is - why are three of the SCSI controllers are shown as Ultra Wide Single-Ended and only one as Ultra160 Wide LVD? Should not all controllers be Ultra160?

Sorry Torsten,

I saw the link that you posted too late. What I can get out of this post is that a C1010 controller is capable of Ultra160 even if he is shown as Single-Ended.

[Torsten.]

OK, try this - while in boot menu service menu:

scsi rate 0/0/0/2/0 nolimit

[Rudolf Fischer]

I´ve altered the SCSI parameters in service menu many times before. Changed it to ULTRA160 and back to UNLIMITED with no success. As you can see in my first post - all SCSI rate and Bus Width parameters at MAX.

I remembered something else. The SCSI service menu for the rp3440 shows a column Auto Termination and the value was ON. That column is not available anymore for the rp8420. Could this be an indication of our problem?

[Torsten.]

I found a hint it could change with setting nolimit. Worth to try.

[Rudolf Fischer]

Hi Torsten,

I´ve executed the scsi command with option nolimit in service menu again without success.  After reboot of OS nothing has changed. The "Negotiated Target Values" remains at 40 MB/s.

The latest firmware 4.20 is installed. Don´t know how to get the SCSI bus working at the highest speed possible.

[Torsten.]

running out of ideas now ... :-(

What else to try?

Maybe this:

# what /stand/vmunix | grep c8xx
It’s important that the c8xx (ultra160) driver has all 3 objects (scsi_c8xx_dbg.c, scsi_c8xx.c &
scsi_c8xx_pdk.c). If not, install the latest Ultra160 patch (e.g. PHKL_29685).

What OS version is running?

According to the patch it is HP-UX 11.11.

Patch notes say

PHKL_25020:  This patch is one of the three needed to
support the SCSI Ultra160 interface on HP-UX 11.11.  The
three patches are PHKL_25020, PHKL_24854 and PHKL_24031.
These patches may be installed independently of each other
and in any order.