Consolidating Filesystems in AIX

Have you needed to consolidate and migrate a filesystem that is spread over 2 physical disks onto 1 physical disk? You can easily do this in AIX without even unmounting the FS.

mjd@techmute mjd $ lspv

hdisk0          00007690a14d9fee                    rootvg

hdisk4          00007690a14cae39                    None

hdisk5          0000769091324b51                    rootvg

There is a FS on testlv that resides in rootvg but has active storage on both hdisk0 and hdisk5. To consolidate and move that filesystem to hdisk4, its as simple as 3 commands:

extendvg rootvg hdisk4

migratepv -l testlv hdisk5 hdisk4

At this point, half of the testlv is on hdisk4, and half is on hdisk0:

mjd@techmute mjd $ lspv -l hdisk4

hdisk4:

LV NAME               LPs   PPs   DISTRIBUTION          MOUNT POINT

testlv                100   100   00..67..33..00..00    /test

mjd@techmute mjd $ lspv -l hdisk0

hdisk0:

LV NAME               LPs   PPs   DISTRIBUTION          MOUNT POINT

[...]

testlv                100   100   39..61..00..00..00    /test

[...]

To finish the consolidation/move, migrate the last half.

mjd@techmute mjd $ migratepv -l testlv hdisk0 hdisk4

mjd@techmute mjd $ lspv -l hdisk4

hdisk4:

LV NAME               LPs   PPs   DISTRIBUTION          MOUNT POINT

testlv                200   200   66..67..67..00..00    /test

This is easier than trying to use cplv or restoring a backup onto the new disk.