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How to Compare File System IO to ZFS Pool and Device Level (Doc ID 1402953.1)

Last updated on JANUARY 03, 2023

Applies to:

Oracle Communications Messaging Server - Version 6.0.0 and later
Oracle Solaris on SPARC (64-bit)
Oracle Solaris on x86-64 (64-bit)


When separate ZFS pools are used for each type of file system used by Messaging Server, you can monitor the IO statistics with the zpool iostat command.  But customers often do not configure it that way.  More often they create one pool and put all the file systems in that pool. (Or, worse yet, everything in one file system in the one pool.) The  iostat command only shows the overall IO activity for the devices that comprise the pool.  The zpool iostat command only shows the entire pool.  How can you tell which file systems are involved in the highest IO activity?

For information about using ZFS and the types of file systems used by Messaging Server, see Best Practices for Oracle Communications Messaging Server and Oracle Solaris ZFS and High Access Messaging Server Directories.

This article provides an example script to gather statistics from your system and an example spread sheets to analyze that data.  The script requires customization per your individual configuration.  Another script is provided to extract data to a form that can be cut-n-pasted into the the spreadsheet.

Troubleshooting Steps

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In this Document
Troubleshooting Steps
 Configuration and Tuning Best practices
 iostat, zpool iostat, and fsstat - and DTrace
 Why create separate file systems even if not separate pools?
 Identify file systems and types of data
 The script to gather data
 Example zpool iostat output
 Example iostat output
 Extracting the data to paste into spreadsheet
 Identify the timing of the symptoms
 The fssstat data
 The iostat data
 The zpool iostat data
 Analyze the graphs

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