here is the procedure i use for replacing disks in my 43p-150's that
have two mirrored disks:

Fixed Disk Replacement / Mirror Rebuilding
===========================================
[Bad drive referred to as hdiskX, good drive referred to as hdiskY]

Break Mirror
smit: System Storage Management
Logical Volume Manager
Volume Groups
Unmirror a Volume Group
VOLUME GROUP name: rootvg
PHYSICAL VOLUME names: hdiskX
Number of COPIES of each logical: 1
partition

Remove Disk from Volume Group
command: reducevg -d rootvg hdiskX

Remove Disk from ODM Database
command: rmdev -l hdiskX -d

Update BVL and Disk Pointers
command: bosboot -a -d hdiskY

Update Bootlists
command: bootlist -m both hdiskY

Shutdown system & Replace Physical Disk

Boot System

Add Disk to ODM Database
command: cfgmgr

Add Disk to Volume Group
command: extendvg rootvg hdiskX

Mirror Disks
smit: System Storage Management
Logical Volume Manager
Volume Groups
Mirror a Volume Group
VOLUME GROUP name: rootvg
Mirror sync mode: [Foreground]
PHYSICAL VOLUME names: [hdiskX]
Number of COPIES of each logical: 2
partition
Keep Quorum Checking On?: no
Create Exact LV Mapping?: yes

Synchronize Mirror
command: syncvg -v rootvg

Update BVL and Disk Pointers
command: bosboot -a

Update Bootlists
command: bootlist -m both hdisk0 hdisk1

Reboot
command: shutdown -Fr or reboot

-------------------------------------------
hope that helps you
bob

mkoster <member14794@dbforums.com> wrote in message news:<3081630.1057587154@dbforums.com>...
> hi,
>
> rs6000 6h0; aix 4.3.3;
>
> we have a defect internal harddisk (hdisk0). the hard disk running in
> raid 1 mirror with hdisk1.
>
> how is the best way, to change the disk hdisk0 without lost data ???
>
> thanks
> marcus
>
> the errorlog:
> >>>>>
>
> LABEL: DISK_ERR2
> IDENTIFIER: A668F553
>
> Date/Time: Mon Jul 7 04:01:17
> Sequence Number: 3118
> Machine Id: 005731AA4C00
> Node Id: luxtf002
> Class: H
> Type: PERM
> Resource Name: hdisk0
> Resource Class: disk
> Resource Type: scsd
> Location: 40-60-00-4,0
> VPD:
> Manufacturer................IBM
> Machine Type and Model......DDYS-T09170N
> FRU Number..................07N3778
> ROS Level and ID............53395241
> Serial Number...............4DGRB903
> EC Level....................F79924
> Part Number.................07N3821
> Device Specific.(Z0)........000003029F00013A
> Device Specific.(Z1)........07N4922
> Device Specific.(Z2)........0933
> Device Specific.(Z3)........01290
> Device Specific.(Z4)........0001
> Device Specific.(Z5)........22
> Device Specific.(Z6)........F79924
>
> Description
> DISK OPERATION ERROR
>
> Probable Causes
> DASD DEVICE
>
> Failure Causes
> DISK DRIVE
> DISK DRIVE ELECTRONICS
>
> Recommended Actions
> PERFORM PROBLEM DETERMINATION PROCEDURES
>
> Detail Data
> SENSE DATA
> A04 0000 2800 006D 5598 0000 0800 0000 0102 0000 F000 0400 6D55
> 9818 0000 0000
> 0200 0080 0001 8505 0001 0000 1498 00FF 011D 0000 0000 0000 0000
> 0000 0000 0000
> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
> 0000 0000 0000
> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
> 0000 0000 0000
> 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0001 DF08 000B 4A00
> ------------------------------------------------------------------
> ----------
> LABEL: LVM_SA_STALEPP
> IDENTIFIER: EAA3D429
>
> Date/Time: Mon Jul 7 04:01:11
> Sequence Number: 3117
> Machine Id: 005731AA4C00
> Node Id: luxtf002
> Class: S
> Type: UNKN
> Resource Name: LVDD
>
> Description
> PHYSICAL PARTITION MARKED STALE
>
> Detail Data
> PHYSICAL VOLUME DEVICE MAJOR/MINOR
> 0016 0000
> PHYSICAL PARTITION NUMBER (DECIMAL)
> 218
> LOGICAL VOLUME DEVICE MAJOR/MINOR
> 000A 0003
> SENSE DATA
> 0057 31AA 1DAA 81E6 0000 0000 0000 0000 0057 31AA 9405 B243 0000
> 0000 0000 0000