SUPPORT COMMUNICATION - CUSTOMER BULLETIN DOCUMENT ID: c02678348

[Eddie Salvatierra]

Hi All.

Have just received the above bulletin :

SUPPORT COMMUNICATION - CUSTOMER BULLETIN
Document ID: c02678348

Version: 1

CUSTOMER BULLETIN: HP-UX: VxFS data integrity concern with write (2) system call with O_SYNC/O_DSYNC flag set
NOTICE: The information in this document, including products and software versions, is current as of the Release Date. This document is subject to change without notice.
Release Date: 2011-01-07

Last Updated: 2011-01-07


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DESCRIPTION
This bulletin is to advise you of a data integrity concern related to the VxFS file-system that is used on HP systems running HP-UX 11iv1, HP-UX 11iv2, HP-UX 11iv3 operating systems or updated releases.

The HP systems that use any version of VxFS file-system on HP-UX 11iv1, HP-UX 11iv2 and HP-UX 11iv3 operating systems and perform O_SYNC/O_DSYNC write I/O of any size that involves changes to a file size are impacted. This issue may be seen only if the system crashes or the device becomes offline unexpectedly immediately after the write (2) system call returns. After the recovery of file system by fsck (1M), the effect of last successful O_SYNC/O_DSYNC write (2) with extending the file size would be lost.

SCOPE
Affected Operating Systems:

HP-UX 11i v1

HP-UX 11i v2

HP-UX 11i v3

RESOLUTION
HP recommends that system administrators follow these steps on all systems running HP-UX 11iv1, HP-UX 11iv2 or HP-UX 11iv3 operating systems:
Schedule system downtime to install relevant patches as soon as possible - please see below for patch numbers.

Apply HP-UX patches for all the version(s) of VxFS file-system used on the system. At this point, possibilities of new data integrity compromises have been eliminated.

Downloadable Solutions
Product Description Patch ID Expected Patch Release Date Download location
HP-UX 11iv3 VxFS 4.1 PHKL_41710 Mid of January 2011 http://itrc.hp.com
HP-UX 11iv3 VxFS 5.0 PHKL_41621 Already available
HP-UX 11iv3 VxFS 5.0.1 PHKL_41728 End of January 2011
HP-UX 11iv2 VxFS 3.5 PHKL_41708 End of January 2011
HP-UX 11iv2 VxFS 4.1 TBD Mid of March 2011
HP-UX 11iv2 VxFS 5.0 TBD End of April 2011
HP-UX 11iv1 VxFS 3.3 PHKL_41709 Mid of February 2011
HP-UX 11iv1 VxFS 3.5 TBD End of February 2011


Can someone advise on how to check if O_SYNC/O_DSYNC write I/O is set/ not set?


Thanks in advance for your replies.

Regards

Eddie

[Dave Johnson_1]

The O_SYNC/O_DSYNC mentioned in the communication are flags passed to open(2) when the file is opened. You cannot know how a file is opened unless you have access to the code.
Sorry,
-Dave

[Dennis Handly]

>Can someone advise on how to check if O_SYNC/O_DSYNC write I/O is set/not set?

Besides looking at the source as Dave mentioned, you run tusc on your running application to look at the open(2)/creat(2) parms.