HP HA s Software manual Rules for RAID Arrays, Pvsummary Calculations Case Conclusion State

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Monitoring Disk Resources

Rules for Using the EMS Disk Monitor with MC/ServiceGuard

Table 2-6 is a summary of how pv_summary is calculated where

•n is the number of paths for the volume group in /etc/lvmtab, (physical volumes, paths, or LUNs).

•p is the number of PVGs physical volume groups in the volume group.

•x is the number of paths currently available from a SCSI inquiry.

To give pv_summary the most accurate picture of data availability, you need to use PVGs to deﬁne your physical volumes as separate access points to data: mirroring should be PVG strict and arrays should have PV links, with redundant links in a separate PVG. Note that if you do not conﬁgure PV links into separate PVGs, p in Table 2-6 will always be equal to 1. Therefore any SCSI inquiry that does not return a value of UP for every path will result in a calculation of DOWN for pv_summary.

Table 2-6		pv_summary Calculations

		Case	Conclusion	State

	x = n		All physical volumes and all data are available.	UP

	x=n-(p-1)		All data is available.	PVG_UP

			If there are PVGs, and one PVG has all paths,	PVG_UP
	n/p <= x <= n-(p-1)		then all data is available.
	n/p <= x <= n-(p-1)
			If there are PVGs, and none of the PVGs has all	SUSPECT
			paths, then the disk monitor cannot determine if
			all data is available.

	x < n/p		Missing some data.
				DOWN
	x=0		No data or physical volumes are available.	DOWN
	x=0		No data or physical volumes are available.

Rules for RAID Arrays

RAID conﬁgurations must be conﬁgured with PV links. PV links are redundant links attached to separate controllers on the array. If PV links are conﬁgured, LVM automatically switches to the alternate controller when one fails.

To use the EMS disk monitor with MC/ServiceGuard, PV links must be conﬁgured in a separate PVGS (physical volume groups). This new requirement allows pv_summary to accurately calculate data availability based on physical volume availability, thus including both ACTIVE and INACTIVE volume groups. If PV

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Contents Using EMS HA Monitors B5735-90001 AugustLegal Notices Contents Monitoring Cluster Resources Monitoring Network InterfacesTroubleshooting Monitoring System ResourcesGlossary Contents Printing History Printing Date Part Number EditionB5735-90001 Page Preface PublicationsPage Installing and Using EMS Event Monitoring Services High Availability Monitors What are EMS HA Monitors?Chapter Role of EMS HA Monitors in a High Availability Environment Installing and Removing EMS HA Monitors Installing EMS HA MonitorsRemoving EMS HA Monitors Status AvailMB Using EMS HA MonitorsEvent Monitoring Service Resource Class Hierarchy PvpvlinkEvent Monitoring Service Screen Selecting a Resource to Monitor ScreenUsing Wildcards Creating a Monitoring Request Monitoring Request ParametersHow Do I Tell EMS When to Send Events? What is a Polling Interval? Which Protocols Can I Use to Send Events?What is a Notiﬁcation Comment? Copying Monitoring Requests Modifying Monitoring RequestsRemoving Monitoring Requests Conﬁguring MC/ServiceGuard Package Dependencies Service EMSPackage Conﬁguration Screen Package Resource Dependencies Screen Resource Parameters Screen Using EMS HA Monitors Monitoring Disk Resources Monitoring Disk Resources Disk Monitor Reference Disk Monitor Resource Class HierarchyPhysical Volume Summary Interpreting Physical Volume SummaryDisk Monitor Reference Physical Volume and Physical Volume Link Status Interpreting Physical Volume and Physical Volume Link StatusLogical Volume Summary Interpreting Logical Volume SummaryLogical volume is inactive Logical Volume StatusInterpreting Logical Volume Status Logical volume is DOWN, a complete copy of the data is notLogical Volume Number of Copies Interpreting Logical Volume CopiesRules for Using the EMS Disk Monitor with MC/ServiceGuard Rules for Using the EMS Disk Monitor with MC/ServiceGuard Rules for RAID Arrays Pvsummary Calculations Case Conclusion StateCreating Volume Groups on Disk Arrays Using PV Links Adding PVGs to Existing Volume Groups# mkdir /dev/vgdatabase Creating Logical Volumes Rules for Mirrored Individual Disks Creating Disk Monitoring Requests Disk Monitoring Request Suggestions Parameters When Disks Fail Resources to Monitor for RAID Arrays RAID Array ExamplePvgup Return Resources to Monitor for Mirrored Disks Mirrored Disks ExampleMonitoring Parameters Resource Notify Condition Option Number Pvsummary Valid Meaning Value Devices Resources to Monitor for Lock DisksExample for Interpreting the pvsummary for Mirrored Disks Resource Monitoring Parameters Notify Condition OptionResources to Monitor for Root Volumes Monitoring Cluster Resources Cluster Monitor Reference Cluster Monitor Resource Class HierarchyCluster Cluster Status Interpreting Custer StatusNode Status Interpreting Node StatusPackage Status Interpreting Package StatusCreating Cluster Monitoring Requests Monitoring Network Interfaces Network Monitor Reference Network Monitor Resource Class HierarchyInterpreting LAN Interface Status Chapter 30 sec Net/interfaces/lan/status/LANname When value isConﬁguring Network Monitoring Requests HourMonitoring System Resources System Monitor Reference System Resource Monitor Class HierarchyNumber of Users Interpreting Number of UsersResource Name Value Range Interpretation Job Queues Interpreting Job QueuesResource Name Value Interpretation Range Filesystem Available Space Filesystem Available SpaceResource Name Creating System Resource Monitoring Requests 6Troubleshooting EMS Directories and Files Etc/opt/resmon/log Logging and tracing EMS LoggingEMS Tracing System Performance Issues Network Performance IssuesPerformance Considerations Testing Cluster Monitor Requests Testing Monitor RequestsTesting Disk Monitor Requests Testing Network Monitor RequestsMaking Sure Monitors are Running Glossary Notiﬁcation See alert Glossary Glossary Index Index Index