IBM MQ support position for 4K physical sector drives on Microsoft Windows systems
Preventive Service Planning
Current versions of Microsoft Windows provide support for hard disk drives with a 4KB physical sector size. This technology is not supported by IBM MQ for drives used to store the queue manager's recovery logs.
Current versions of Microsoft Windows provide support for hard disk drives with a 4KB physical sector size. This includes "Advanced Format " hard disk drive functionality also known as "512E", which allows 512-byte sector size emulation on disks with a 4K sector size.
This technology is not supported by IBM MQ for drives used to store the queue manager's recovery logs.
Drives used for queue managers' recovery logs on Microsoft Windows must use 512-byte native physical and logical sector size.
This restriction does not apply to supported UNIX operating systems.
On Microsoft Windows systems, a queue manager's transaction log is written as a series of 1KB-aligned 512-byte pages. These are unbuffered writes, and confirmation from the OS of successful completion of the write to persistent storage is required by IBM MQ in order to advance the transaction log.
Because these writes are not 4KB-aligned, it is possible that the Microsoft Windows Advanced Format emulation layer may re-write sectors for which a successful write confirmation has already been returned for IBM MQ. A failure during such a re-write could invalidate IBM MQ's transactional integrity and so this technology is not appropriate for IBM MQ recovery logs.
To confirm if a drive is suitable for a queue manager's recovery logs, the following Microsoft Windows command can be issued:
|fsutil fsinfo ntfsinfo <drive letter>|
In the resulting output, both the "Bytes Per Sector" and "Bytes Per Physical Sector" must report 512:
More support for:
Software version: 7.5, 8.0, 9.0, 9.0.1, 9.0.2, 9.0.3
Operating system(s): Windows
Software edition: All Editions
Reference #: 2006146
Modified date: 18 July 2017
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