veritas vxdmp.pdf

Veritas VXDMP What is Dynamic Multipathing (DMP)? DMP is a method of providing two or more hardware paths to a single drive. For example, the physical hardware can have at least two paths, such as c1t1d0 and c2t1d0, directing I/O to the same drive. VxVM arbitrarily selects one of the two names and creates a single device entry, then transfers data across both paths to spread the I/O, DMP is enabled by default. Volume Manager detects multipath systems with the Universal Worldwide Device Identifiers(WWD IDs) and manages multipath targets, such as disk arrays, which define policies for using more than one path. Benefits of DMP High availability - DMP provides greater reliability through a path failover mechanism. In the event of a loss of one connection to a disk, the system continues to access the critical data over the other sound connections until the failed path is replaced. Improved performance - DMP provides greater I/O throughput by balancing the I/O load uniformly across multiple I/O paths to the disk device. The disk paths can be in a active/active (use both paths) or active/passive state (use one path). list controllers vxdmpadm listctlr all list enclosures vxdmpadm listenclosure all vxdmpadm listenclosure <enclosure> Display Paths vxdmpadm getsubpaths ctlr=fscsi2 vxdmpadm getsubpaths dmpnodename=<dmp-device-name> Who controls the path vxdmpadm getdmpnode nodename=c3t2d0 vxdmpadm getdmpnode enclosure=<enclosure> Controller (enable/disable) vxdmpadm disable ctlr=<controller> vxdmpadm enable ctlr=<controller> Statistics vxdmpadm iostat start vxdmpadm iostat reset vxdmpadm iostat show all I/O balancing & load vxdmpadm getattr enclosure <enclosure> iopolicy vxdmpadm setattr enclosure <enclosure> iopolicy=<policy> adaptive priority balanced (default) round-robin minimumq single-active Path Type vxdmpadm setattr path <path-name> pathtype=<path-type> active nomanual nopreffered primary secondary standby Displays the restore/error daemon vxdmpadm stat restored vxdmpadm stat errord Starts the restore daemon vxdmpadm start restored Stops the restore daemon vxdmpadm stop restored Veritas VxDMP http://www.datadisk.co.uk/html_docs/veritas/veritas_vxdmp.htm 1 of 1 3/1/14 11:26 AM

Upload: anvesh-reddy

Post on 10-Dec-2015

221 views

Category:

Documents

4 download

Report

Download

Embed Size (px):

DESCRIPTION

Veritas VxDMP.pdf

TRANSCRIPT

Veritas VXDMP

What is Dynamic Multipathing (DMP)?

DMP is a method of providing two or more hardware paths to a single drive. For example, the physical hardware can haveat least two paths, such as c1t1d0 and c2t1d0, directing I/O to the same drive. VxVM arbitrarily selects one of the twonames and creates a single device entry, then transfers data across both paths to spread the I/O, DMP is enabled by default.Volume Manager detects multipath systems with the Universal Worldwide Device Identifiers(WWD IDs) and managesmultipath targets, such as disk arrays, which define policies for using more than one path.

Benefits of DMP

High availability - DMP provides greater reliability through a path failover mechanism. In the event of a loss of oneconnection to a disk, the system continues to access the critical data over the other sound connections until the failedpath is replaced.Improved performance - DMP provides greater I/O throughput by balancing the I/O load uniformly across multipleI/O paths to the disk device.

The disk paths can be in a active/active (use both paths) or active/passive state (use one path).

list controllers vxdmpadm listctlr all

list enclosuresvxdmpadm listenclosure all

vxdmpadm listenclosure <enclosure>

Display Pathsvxdmpadm getsubpaths ctlr=fscsi2

vxdmpadm getsubpaths dmpnodename=<dmp-device-name>

Who controls the pathvxdmpadm getdmpnode nodename=c3t2d0

vxdmpadm getdmpnode enclosure=<enclosure>

Controller (enable/disable)vxdmpadm disable ctlr=<controller>

vxdmpadm enable ctlr=<controller>

Statistics

vxdmpadm iostat start