What's New as of December 29th, 1999

Changes For This Release

The following changes have been made to scu for this release:

Implementation Notes

Locating the SCSI devices is accomplished by searching the device directory, i.e. /dev or /dev/{changer,ntape,rdisk), and issuing a system dependent IOCTL to obatin the SCSI bus, target, and lun. Device scanning only occurs when a "show edt" command is executed, so single device access does not incur the directory search/device IOCTL overhead.

Since the device is actually openned to obatin this information, it is possible the open could block or be slow if no media is present. Note: If not running as 'root', you must have read access to the device. In this case, no errors are reported, but no device name will be reported.

For tape devices, the no-rewind device is used to avoid rewinding the tape when it is closed. For disk devices, the open is done only on the major disk name, i.e., Linux: /dev/sda, Tru64 Unix: /dev/rrz0c, etc, so you will only see these device names listed in the "show edt" display.

On Tru64 Unix, the tagged queuing depth is reported (if supported). This information may be useful for saturating tagged requests with AIO.

On TruClusters, only local devices are reported, and 'scu' now ensures remote devices are not selected to avoid operations to the wrong SCSI device (a very nasty problem). The remote check is performed using the hardware manager 'hwmgr', which requires 'root' privileges to run.

If you have problems with this new feature, please report it to myself, and then use one of the methods described above to disable it.

NOTE: This work is provided by the Data Products Group, managed by Charlie Newfell. These changes are not currently part of the Tru64 release.

Within Compaq, the updated scu kits are located @ URL:

http://www.zk3.dec.com/~rmiller/scu.html


Mail Send mail to admin of this page: [email protected] Home To Robin's home page.

Last modified: December 29th, 1999


Examples:


Linux V6.1 Example:
-------------------

linux% scu show edt

Equipment Device Table (EDT) Information:

    Bus/Target/Lun Device Type  ANSI  Vendor ID    Product ID    Revision N/W
    -------------- ----------- ------ --------- ---------------- -------- ---
/dev/sda /dev/sga
     0    0    0   Direct      SCSI-2 COMPAQ    DDRS-39130W        S99C    W
/dev/nst0 /dev/sgb
     0    3    0   Sequential  SCSI-2 HP        C1557A             U709    N
/dev/sgc
     0    3    1   Changer     SCSI-2 HP        C1557A             U709    N
/dev/sdb /dev/sgd
     1    1    0   Direct      SCSI-2 DEC       RZ29B    (C) DEC   0016    N
/dev/sdc /dev/sge
     1    2    0   Direct      SCSI-2 DEC       RZ29B    (C) DEC   0016    N
/dev/cdrom1 /dev/scd0 /dev/sgf
     1    5    0   CD-ROM      SCSI-2 DEC       RRD46   (C) DEC    1337    N

linux% ls -ls /dev/sd[a-d]
   0 brw-rw-r--   1 root     disk       8,   0 May  5  1998 /dev/sda
   0 brw-rw-rw-   1 root     disk       8,  16 May  5  1998 /dev/sdb
   0 brw-rw-rw-   1 root     disk       8,  32 May  5  1998 /dev/sdc
   0 brw-rw-r--   1 root     disk       8,  48 May  5  1998 /dev/sdd
linux% 

Tru64 Unix V4.0F Example: ------------------------- tru64% export SCU_DEVICE_SCANNING=Yes tru64% scu show edt CAM Equipment Device Table (EDT) Information: Bus/Target/Lun Device Type ANSI Vendor ID Product ID Revision N/W -------------- ----------- ------ --------- ---------------- -------- --- /dev/rrz0c (tags 32) 0 0 0 Direct SCSI-2 DEC RZ1CF-CF (C) DEC 1614 W /dev/rrz1c (tags 32) 0 1 0 Direct SCSI-2 COMPAQ BB01811C9C 3B05 W /dev/rrz2c (tags 32) 0 2 0 Direct SCSI-2 COMPAQ BB01811C9C 3B05 W /dev/rrz4c 0 4 0 CD-ROM SCSI-2 DEC RRD47 (C) DEC 1206 N /dev/mc8a 1 0 0 Changer SCSI-2 DEC TL800 (C) DEC 0506 W /dev/nrmt1h 1 4 0 Sequential SCSI-2 DEC TZ89 (C) DEC 2150 W /dev/nrmt0h /dev/nrmt2h 1 5 0 Sequential SCSI-2 DEC TZ89 (C) DEC 2150 W tru64%
TruCluster V5.0 Example: ------------------------ Cluster# export SCU_DEVICE_SCANNING=Yes Cluster# PATH=".:$PATH" Cluster# time scu show edt CAM Equipment Device Table (EDT) Information: Bus/Target/Lun Device Type ANSI Vendor ID Product ID Revision N/W -------------- ----------- ------ --------- ---------------- -------- --- /dev/rdisk/dsk0c (tags 74) 0 0 0 Direct SCSI-2 DEC RZ28 (C) DEC D41C N /dev/rdisk/dsk1c (tags 74) 0 1 0 Direct SCSI-2 DEC RZ28 (C) DEC D41C N /dev/rdisk/dsk2c (tags 74) 0 2 0 Direct SCSI-2 DEC RZ28 (C) DEC D41C N /dev/rdisk/cdrom0c 0 6 0 CD-ROM SCSI-2 DEC RRD43 (C) DEC 1084 N /dev/rdisk/dsk3c (tags 74) 1 0 0 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk4c (tags 74) 1 0 1 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk5c (tags 74) 1 0 2 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk6c (tags 74) 1 0 3 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk7c (tags 74) 1 0 4 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk8c (tags 74) 1 0 5 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk9c (tags 74) 1 0 6 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk10c (tags 74) 1 0 7 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk11c (tags 74) 1 1 0 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk12c (tags 74) 1 1 1 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk13c (tags 74) 1 1 2 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk14c (tags 74) 1 1 3 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk15c (tags 74) 1 1 4 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk16c (tags 74) 1 2 0 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk17c (tags 74) 1 2 1 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk18c (tags 74) 1 2 2 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk19c (tags 74) 1 2 3 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk20c (tags 74) 1 2 4 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk21c (tags 74) 1 2 5 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk22c (tags 74) 1 2 6 Direct SCSI-2 DEC HSZ40 V32Z W /dev/rdisk/dsk23c (tags 74) 1 2 7 Direct SCSI-2 DEC HSZ40 V32Z W /dev/changer/mc0 2 0 0 Changer SCSI-2 DEC TL800 (C) DEC 0420 W /dev/ntape/tape0c 2 4 0 Sequential SCSI-2 DEC TZ89 (C) DEC 1837 W real 1m18.70s user 0m16.40s sys 0m3.00s Cluster#