Procedure to remove and rediscover ESS disk's

1) Bring down applications.

2) Bring down databases.

3) Unmount all filesystems.

4) Convert all vpath VGs to hdisk VGs

    a) lsvg -o | grep -v rootvg | xargs -n1 varyoffvg
    b) rm /tmp/vp2hd.out
    c) lsvg | grep -v rootvg | while read vg
        do
            vp2hd $vg >> /tmp/vp2hd.out
            echo $vg
        done
    d) Check contents of /tmp/vp2hd.out.  Ensure all VGs converted successfully.
    e) lsvg -o | grep -v rootvg | xargs -n1 varyoffvg #

5) Remove all vpath devices and take dpo down to "Defined" state

    a) lspv | grep vpath | awk '{print $1}' | xargs -n1 rmdev -dl
    b) rmdev -l dpo

6) Remove all FC hdisk devices and fscsi drivers; take FC adapters to "Defined" state

    a) lsdev -Cc driver | grep ^fscsi | awk '{print $1}' | xargs -n1 rmdev -dRl
    b) lsdev -Cc adapter | grep ^fcs | awk '{print $1}' | xargs -n1 rmdev -l

7) Make your SAN change

8) Rediscover all hdisk devices

    a) lsdev -Cc adapter | grep ^fcs | awk '{print $1}' | xargs -n1 cfgmgr -vl

# Or run this by hand one adapter at a time if you prefer

9) Verify all hdisk devices are present

    a) lspv
    b) lsdev -Cc disk

10) Fix queue_depth for all FC hdisks

    a) lsdev -Cc disk | grep 2105 | awk '{print $1}' | \
        xargs -n1 chdev -a queue_depth=20 -l

# NOTE: This will take a long time. We've seen ~45 minutes for about 600 disks

11) Recreate vpath devices

    a) cfgmgr -vl dpo

12) Verify all vpath devices are correct

    a) lsvpcfg
    b) datapath query device

13) Convert all hdisk VGs to vpath VGs

    a) rm /tmp/hd2vp.out
    b) lsvg | grep -v rootvg | while read vg
        do
            hd2vp $vg >> /tmp/hd2vp.out
            echo $vg
        done
    c) Check /tmp/hd2vp.out to ensure all VGs were converted successfully

# Volume groups have been left online by hd2vp

14) Mount all filesystems

15) Bring up databases.

16) Bring up applications