How best to split mirror into new diskgroup?

Description

Using vxsnap

Prepare the volume

# vxsnap -g datadg prepare vol01 ndcomirs=1 alloc=vrts_appliances0_1

Breakoff the second plex into a new volume

# vxsnap -g datadg make source=vol01/newvol=SNAP_vol01/plex=vol01-02 alloc=vrts_appliances0_2

Split the diskgroup
# vxdg split datadg newdg SNAP_vol01

Check vxprint for both diskgroups: datadg & newdg

# vxprint -qhtg datadg
dg datadg default default 5000 1644844695.37.va743a-01

dm vrts_appliances0_1 vrts_appliances0_1 auto 65536 104791760 -

v vol01 - ENABLED ACTIVE 2097152 SELECT - fsgen pl vol01-01 vol01 ENABLED ACTIVE 2097152 CONCAT - RW sd vrts_appliances0_1-01 vol01-01 vrts_appliances0_1 0 2097152 0 vrts_appliances0_1 ENA dc vol01_dco vol01 vol01_dcl v vol01_dcl - ENABLED ACTIVE 67840 SELECT - gen pl vol01_dcl-01 vol01_dcl ENABLED ACTIVE 67840 CONCAT - RW sd vrts_appliances0_1-02 vol01_dcl-01 vrts_appliances0_1 2097152 67840 0 vrts_appliances0_1 ENA sp SNAP_vol01_snp vol01 vol01_dco

# vxprint -qhtg newdg
dg newdg default default 1000 1644844696.38.va743a-01

dm vrts_appliances0_2 vrts_appliances0_2 auto 65536 104791760 -

v SNAP_vol01 - ENABLED ACTIVE 2097152 ROUND - fsgen pl vol01-02 SNAP_vol01 ENABLED ACTIVE 2097152 CONCAT - RW sd vrts_appliances0_2-01 vol01-02 vrts_appliances0_2 0 2097152 0 vrts_appliances0_2 ENA dc SNAP_vol01_dco SNAP_vol01 SNAP_vol01_dcl v SNAP_vol01_dcl - ENABLED ACTIVE 67840 SELECT - gen pl SNAP_vol01_dcl-01 SNAP_vol01_dcl ENABLED ACTIVE 67840 CONCAT - RW sd vrts_appliances0_2-02 SNAP_vol01_dcl-01 vrts_appliances0_2 2097152 67840 0 vrts_appliances0_2 ENA sp vol01_snp SNAP_vol01 SNAP_vol01_dco

Manual method

Break off the plex:

# vxplex -g datadg dis vol01-02

Split the plex to newdg:

# vxdg split datadg newdg vol01-02

Check vxprint
# vxprint -qhtg datadg
dg datadg default default 11000 1644845169.47.va743a-01

dm vrts_appliances0_1 vrts_appliances0_1 auto 65536 104791760 -

v vol01 - ENABLED ACTIVE 2097152 SELECT - fsgen pl vol01-01 vol01 ENABLED ACTIVE 2097152 CONCAT - RW sd vrts_appliances0_1-01 vol01-01 vrts_appliances0_1 0 2097152 0 vrts_appliances0_1 ENA

Make a volume for the plex:

# vxmake -g newdg -U fsgen vol SNAP_vol01 plex=vol01-02

Start the volume:

# vxvol -g newdg start SNAP_vol01

Check vxprint
# vxprint -qhtg newdg
dg newdg default default 14000 1644845170.48.va743a-01

dm vrts_appliances0_2 vrts_appliances0_2 auto 65536 104791760 -

v SNAP_vol01 - ENABLED ACTIVE 2097152 ROUND - fsgen pl vol01-02 SNAP_vol01 ENABLED ACTIVE 2097152 CONCAT - RW sd vrts_appliances0_2-01 vol01-02 vrts_appliances0_2 0 2097152 0 vrts_appliances0_2 ENA

At this point the new volume can be mounted, or deported to another system, and mounted on that system.

# mkdir /newdg
# mount -F vxfs /dev/vx/dsk/newdg/SNAP_voll01 /newdg

NOTE: The -F vxfs option applies to Solaris, -t vxfs for Linux and -V vxfs for AIX.

# ls /newdg
array.info ddlconfig.info disk.info dmppolicy.info jbod.info lost+found

Resolution

In this technote, we start with an already existing mirrored volume. The requirement is to break off one mirror into a separate volume which is in a separate diskgroup.

Starting with volume configuration:

# vxprint -qhtg datadg
dg datadg default default 5000 1644844695.37.va743a-01

dm vrts_appliances0_1 vrts_appliances0_1 auto 65536 104791760 - dm vrts_appliances0_2 vrts_appliances0_2 auto 65536 104791760 -

v vol01 - ENABLED ACTIVE 2097152 SELECT - fsgen pl vol01-01 vol01 ENABLED ACTIVE 2097152 CONCAT - RW sd vrts_appliances0_1-01 vol01-01 vrts_appliances0_1 0 2097152 0 vrts_appliances0_1 ENA pl vol01-02 vol01 ENABLED ACTIVE 2097152 CONCAT - RW sd vrts_appliances0_2-01 vol01-02 vrts_appliances0_2 0 2097152 0 vrts_appliances0_2 ENA

Issue/Introduction

How to split off a mirror from a volume into a new diskgroup.

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