Chapter 10 Notes when Using the Multipath Driver
10.2 Considerations for Linux Servers
FUJITSU Storage ETERNUS Multipath Driver V2 User’s Guide for Linux
Copyright 2014 FUJITSU LIMITED
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10.2
Considerations for Linux Servers
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Stopping and restarting a storage system
To stop or restart a storage system during operation, first shut down the Linux server.
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Syslog messages
When a large number of syslog messages are being output in a short time or the system is under a heavy
load, some of the messages will not be output to the syslog.
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When a known storage system is not found at server startup
When a storage system that has previously been recognized cannot be found when the server is started up,
the following message appears.
where %d is a number and %s is the disk device ID.
Check the state of the storage system indicated by the disk device ID %s and perform any maintenance
necessary to allow the storage system to be recognized again.
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Maximum number and size of disks
The maximum number and size of disks that may be used depend solely on the OS specification. There is no
limitation inherent in the Multipath Driver.
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Maximum number of storage systems recognizable
Up to 256 storage systems (including those via LUN Mapping, Affinity Groups, and zones) can be recognized
by a server.
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Maximum number of storage systems using recognition order
The recognition order function can be used for up to 32 storage systems (including those via LUN Mapping,
Affinity Groups, and zones). The recognition order setup command (mpdconfig -s) will fail if it is executed
when more than 32 storage systems are recognized.
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Changed CM assignments in a storage system with assigned CMs
Path status (active/standby) will only reflect changes in the CM assignments after the server is rebooted.
MPDH%d:WARNING: %s:Device is not found.
When using Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, or SUSE Linux Enterprise Server 11
(Service Pack 1 or later), the recognition order setting function cannot be used.
