Patch Name: PHCO_13198

Patch Description: s700_800 10.20 dd(1) patch for block/unblock conversion

Creation Date: 97/11/25

Post Date:  97/11/25

Hardware Platforms - OS Releases:
	s700: 10.20
	s800: 10.20

Products: N/A

Filesets:
	OS-Core.UX-CORE

Automatic Reboot?: No

Status: General Release

Critical: No

Path Name: /hp-ux_patches/s700_800/10.X/PHCO_13198

Symptoms:
	PHCO_13198:
	When using conv=block/unblock, the output buffer is flushed
	at cbs, rather than obs.  Assuming cbs is much smaller than
	obs (which it normally is), this means the file is written
	in relatively small chunks, requiring a much larger number
	of writes to complete the data copy.  The user can see this
	reflected in the dd(1) output; for "records out", it is
	likely to show 0 (zero) full records and a large number of
	partial records.  This problem is especially significant
	when the output file is a tape device, where inter-record
	gaps (IRGs) occur between writes.  This could result in the
	user reaching end-of-tape very unexpectedly.

Defect Description:
	PHCO_13198:
	dd(1) gives incorrect results when conv=block or
	conv=unblock is used and cbs < obs.  (And under normal
	circumstances, cbs is very likely to be less than obs.)
	For "records out", dd(1) shows 0 (zero) full records and
	a large number of partial records.  This is an especially
	significant issue if the output file is a tape device,
	where the user may reach end-of-tape very unexpectedly as
	a result of the driver inserting inter-record gaps (IRGs)
	between output records.

SR:
	1653209940

Patch Files:
	/usr/bin/dd

what(1) Output:
	/usr/bin/dd:
		$Revision: 78.2.1.1 $
		PATCH_10_20: dd.o 97/11/25

cksum(1) Output:
	4202436784 28672 /usr/bin/dd

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches: None

Patch Package Size: 80 KBytes

Installation Instructions:
	Please review all instructions and the Hewlett-Packard
	SupportLine User Guide or your Hewlett-Packard support terms
	and conditions for precautions, scope of license,
	restrictions, and, limitation of liability and warranties,
	before installing this patch.
	------------------------------------------------------------
	1. Back up your system before installing a patch.

	2. Login as root.

	3. Copy the patch to the /tmp directory.

	4. Move to the /tmp directory and unshar the patch:

		cd /tmp
		sh PHCO_13198

	5a. For a standalone system, run swinstall to install the
	    patch:

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHCO_13198.depot

	5b. For a homogeneous NFS Diskless cluster run swcluster on the
	    server to install the patch on the server and the clients:

		swcluster -i -b

	    This will invoke swcluster in the interactive mode and
	    force all clients to be shut down.

	    WARNING: All cluster clients must be shut down prior to the
		     patch installation.  Installing the patch while the
		     clients are booted is unsupported and can lead to
		     serious problems.

	    The swcluster command will invoke an swinstall session in which
	    you must specify:

		alternate root path  -  default is /export/shared_root/OS_700
		source depot path    -  /tmp/PHCO_13198.depot

	    To complete the installation, select the patch by choosing
	    "Actions -> Match What Target Has" and then "Actions -> Install"
	    from the Menubar.

	5c. For a heterogeneous NFS Diskless cluster:

		- run swinstall on the server as in step 5a to install
		  the patch on the cluster server.

		- run swcluster on the server as in step 5b to install
		  the patch on the cluster clients.

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHCO_13198.  If you do not wish to retain a
	copy of the original software, you can create an empty file
	named /var/adm/sw/patch/PATCH_NOSAVE.

	Warning: If this file exists when a patch is installed, the
	         patch cannot be deinstalled.  Please be careful
		 when using this feature.

	It is recommended that you move the PHCO_13198.text file to
	/var/adm/sw/patch for future reference.

	To put this patch on a magnetic tape and install from the
	tape drive, use the command:

		dd if=/tmp/PHCO_13198.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None