PDP-11 disk image question

Glen Slick glen.slick at gmail.com
Wed Feb 20 22:32:30 CST 2019


After spending way to much time on this today, I verified that at
least on the CMD CQD Q-Bus SCSI controller versions that I have if I
wanted the CMD CQD controller to report an MSCP disk size of exactly
891072 blocks to match the SIMH emulated RA81 disk size, I had to soft
resize the capacity of the SCSI hard drive to be 2 blocks larger, i.e.
a capacity of 891074 blocks. This is with the CMD CQD controller reset
to the default configuration with the 'Z' configuration option. The
behavior of Q-Bus SCSI controllers from other vendors will be
different.

After doing that I verified that VMS on a VAX CPU, and also the
2.11BSD standalone disklabel on a PDP-11 CPU saw an MSCP disk size of
891072 blocks with the SCSI disk size of 891074 blocks attached to the
CMD CQD Q-Bus SCSI controller.

I then installed RSTS/E 10.1 on a SIMH RA81 and then did the
equivalent of a dd from the SIMH RA81 disk image file of size
456,228,352 bytes to the SCSI hard drive of capacity 891074 blocks.
Then the PDP-11 CPU booted RSTS/E 10.1 from SCSI hard drive attached
to the CMD CQD Q-Bus SCSI controller.

Sorry for the extra long message. Gory details below. If I don't add
the details now I'll forget all the details myself tomorrow.

Resizing the 9GB SCSI hard drive down to a capacity of 891074 blocks
on a Windows PC using sg3_utils-1.37 (I seem to recall that previously
I tried this with a newer version of sg3_utils and something didn't
work right):

C:\sg3_utils-1.37>sg_scan
PD0     [C]     HDS728040PLAT20  PF1OA21B
PD1             IBM       DDRS-39130D       DC1B
CDROM0  [Z]     TEAC CD-224E  1.7A

C:\sg3_utils-1.37>sg_inq pd1
standard INQUIRY:
  PQual=0  Device_type=0  RMB=0  version=0x02  [SCSI-2]
  [AERC=0]  [TrmTsk=0]  NormACA=0  HiSUP=0  Resp_data_format=2
  SCCS=0  ACC=0  TPGS=0  3PC=0  Protect=0  [BQue=0]
  EncServ=0  MultiP=0  [MChngr=0]  [ACKREQQ=0]  Addr16=0
  [RelAdr=0]  WBus16=1  Sync=1  Linked=1  [TranDis=0]  CmdQue=1
  [SPI: Clocking=0x0  QAS=0  IUS=0]
    length=164 (0xa4)   Peripheral device type: disk
 Vendor identification: IBM
 Product identification: DDRS-39130D
 Product revision level: DC1B
 Unit serial number: RE1X3474

C:\sg3_utils-1.37>sg_readcap pd1
Read Capacity results:
   Last logical block address=17849999 (0x1105e8f), Number of blocks=17850000
   Logical block length=512 bytes
Hence:
   Device size: 9139200000 bytes, 8715.82 MiB, 9.1392 GB

C:\sg3_utils-1.37>sg_format --count=891074 --resize --verbose pd1
    inquiry cdb: 12 00 00 00 24 00
    IBM       DDRS-39130D       DC1B   peripheral_type: disk [0x0]
      PROTECT=0
    mode sense (10) cdb: 5a 00 01 00 00 00 00 00 fc 00
    mode sense (10): pass-through requested 252 bytes but got 28 bytes
Mode Sense (block descriptor) data, prior to changes:
  Number of blocks=17850000 [0x1105e90]
  Block size=512 [0x200]
    mode select (10) cdb: 55 11 00 00 00 00 00 00 1c 00
Resize operation seems to have been successful

C:\sg3_utils-1.37>sg_readcap pd1
Read Capacity results:
   Last logical block address=891073 (0xd98c1), Number of blocks=891074
   Logical block length=512 bytes
Hence:
   Device size: 456229888 bytes, 435.095 MiB, 0.45623 GB

Verifying that the SCSI hard drive with a capacity of 891074 blocks
attached to the CMD CQD Q-Bus SCSI controller is seen as a drive with
a capacity of 891072 blocks on VMS on a VAX CPU:

$ MOUNT /FOREIGN BA215$DUA0:
%MOUNT-I-MOUNTED, OVMSVAXSYS mounted on _BA215$DUA0:
$ SHOW DEVICE /FULL BA215$DUA0:

Disk BA215$DUA0:, device type RA81, is online, allocated, deallocate on
    dismount, mounted foreign, file-oriented device, shareable, available to
    cluster, error logging is enabled.

    Error count                    0    Operations completed                  4
    Owner process           "SYSTEM"    Owner UIC                      [SYSTEM]
    Owner process ID        00000214    Dev Prot            S:RWPL,O:RWPL,G:R,W
    Reference count                2    Default buffer size                 512
    Total blocks              891072    Sectors per track                   217
    Total cylinders              411    Tracks per cylinder                  10

    Volume label        "OVMSVAXSYS"    Relative volume number                0
    Cluster size                   0    Transaction count                     1
    Free blocks                    0    Maximum files allowed                 0
    Extend quantity                0    Mount count                           1
    Mount status             Process    ACP process name                     ""

  Volume Status:  Unknown ACP type.

Verifying that the SCSI hard drive with a capacity of 891074 blocks
attached to the CMD CQD Q-Bus SCSI controller is seen as a drive with
a capacity of 891072 blocks on the 2.11BSD standalone disklabel on a
PDP-11 CPU (ignore the "45Boot" which is a 2.11BSD bug that is fixed
in a newer patch to correctly report "53Boot" on an 11/53 CPU).

9 8 7 6 5 4 3 2 1

Commands are Help, Boot, List, Map, Test and Wrap.
Type a command then press the RETURN key: BOOT MU0

MU0

45Boot from tms(0,0,0) at 0174500
: tms(0,1)
Boot: bootdev=06001 bootcsr=0174500
disklabel
Disk? ra(0,0)
'ra(0,0)' is unlabeled or the label is corrupt.
Proceed? [y/n] y
d(isplay) D(efault) m(odify) w(rite) q(uit)? D
d(isplay) D(efault) m(odify) w(rite) q(uit)? d

type: MSCP
disk: RA81
label: DEFAULT
flags:
bytes/sector: 512
sectors/track: 217
tracks/cylinder: 10
sectors/cylinder: 2170
cylinders: 410
rpm: 3600
drivedata: 0 0 0 0 0

1 partitions:
#        size   offset    fstype   [fsize bsize]
  a: 891072 0  2.11BSD    1024 1024     # (Cyl. 0 - 410*)

d(isplay) D(efault) m(odify) w(rite) q(uit)? q
Label changed. Discard changes [y/n]? y

45Boot from tms(0,0,1) at 0174500
:

Booting RSTS/E 10.1 from the SCSI hard drive with a capacity of 891074
blocks attached to the CMD CQD Q-Bus SCSI controller after the SIMH
emulated RA81 disk image file with the RSTS/E 10.1 was dd to the SCSI
hard drive:

9 8 7 6 5 4 3 2 1

Commands are Help, Boot, List, Map, Test and Wrap.
Type a command then press the RETURN key: BOOT DU0

DU0

RSTS V10.1-L RSTS   (DU0) INIT V10.1-0L

Today's date? 20-FEB-19

Current time? 19:46

Start timesharing? <Yes>

<stuff deleted>

RSTS V10.1-L 20-Feb-19 07:46 PM
User: 1,2
Password:

Jobs detached under this account:
   Job  What  Size  State   Run-time   RTS
    1  ERRCPY 5K    SR          13.6  ...RSX
    3  OMS    9K    SL           1.6  ...RSX
    4  PBS... 19K   SL           1.6  ...RSX
Job number to attach to?
Last interactive login on 20-Feb-19, 07:46 PM at KB0:
Last non-interactive login on 20-Feb-19, 07:46 PM
3 other users are logged in under this account

$ SHOW DISK

Disk Structure:
Dsk  Open    Size      Free    Clu   Err Name      Level  Comments
DU0    22  891072  837824  94%  16     0 RSTS10     1.2   Pub, DLW


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