AIX bootdisk removal

Need to replace a failed rootdisk in AIX? The post below outlines the procedure for removing a disk from a mirrored root volume.

First take a look at what disks are in your rootvg.

In the example below we have hdisk0 and hdisk1

# lsvg -p rootvg
rootvg:
PV_NAME
PV STATE          TOTAL
PPs   FREE PPs    FREE DISTRIBUTION
hdisk0
active
542         264
109..00..00..46..109
hdisk1
 active
 542         278
 88..00..00..81..109

 lsvg -l rootvg

 LV
 NAME
 TYPE       LPs   PPs
 PVs  LV STATE      MOUNT POINT

 hd5
 boot       1
 2     2    closed/syncd  N/A

hd6

paging     64    128

2    open/syncd    N/A

hd8

jfslog     1     2

2    open/syncd    N/A

hd4

jfs        6

12    2    open/syncd

/

hd2

jfs        127   254

2    open/syncd    /usr

hd9var

jfs        4

8     2    open/syncd

/var

hd3

jfs        37

74    2    open/syncd

/tmp

hd1

jfs        3

6     2    open/syncd

/home

hd10opt

jfs        21

42    2    open/syncd

/opt

dumplv
 sysdump    14    14
 1    open/syncd    N/A

Now lets check to make sure that there’s a 1:2 relationship, meaning that there are copies.

Notice dumplv. It’s not copied so we need to make sure dumplv data isn’t on the failing disk. To check, run;

$ lslv -l dumplv
dumplv:N/A
PV
COPIES        IN BAND
DISTRIBUTION
hdisk0
014:000:000   100%
000:014:000:000:000

This is telling us that the logical volume dumplv is on hdisk0.  If hdisk1 is the failing
disk, then we are okay.  Otherwise, we would have to migrate the data over to the good drive and proceed.

# unmirrorvg rootvg hdisk1
# reducevg rootvg hdisk1
# rmdev -l hdisk1 –d

Before you power down, you need to make sure that your system is set to boot off of a disk that is still in the rootvg.

# bootinfo -b
hdisk1

This tells you what drive it was last booted up.  We want to change this to boot to the new drive, so;

# bosboot -ad
 /dev/hdisk0

And check bootlist

# bootlist –m normal
 –o

NOW WE CAN POWER DOWN THE BOX AND REPLACE THE DRIVE. Once disk has been replaced,
power up the server.  Once at command prompt, run;

# cfgmgr

This will install the new device and allow the OS to see it.

 lsdev -Cc disk

 hdisk0
 Available 40-60-00-4,0 16 Bit LVD SCSI Disk Drive

 hdisk1
 Available 40-60-00-8,0 16 Bit LVD SCSI Disk Drive

Make sure that the OS says it’s available.  If it is, we can assign it to a volume group.

# extendvg rootvg hdisk1

 This will assign it a PVID. and assign it to the volumegroup rootvg to make it available for use.  Now we can mirror;

# mirrovg rootvg

This will take a little while as it’s taking all data now on hdisk0 and making a copy to hdisk1.

# lsvg -p rootvg
rootvg:
PV_NAME
PV STATE          TOTAL
PPs   FREE PPs    FREE DISTRIBUTION
hdisk0
active
542         264
109..00..00..46..109
hdisk1
 active
 542         278
 88..00..00..81..109

Once it’s mirroring, we can make sure it’s assigned to rootvg by doing the above.  We can also check to make sure there’s copies;

# lsvg -l rootvg
rootvg:
LV
NAME
TYPE       LPs   PPs
PVs  LV STATE      MOUNT POINT
hd5
boot       1
2     2    closed/syncd  N/A
hd6
paging     64    128
2    open/syncd    N/A
hd8
jfslog     1     2
2    open/syncd    N/A
hd4
jfs        6
12    2    open/syncd
/
hd2
jfs        127   254
2    open/syncd    /usr
hd9var
jfs        4
8     2    open/syncd
/var
hd3
jfs
37    74    2
open/syncd    /tmp
hd1
jfs        3
6     2    open/syncd
/home
hd10opt
jfs        21
42    2    open/syncd
/opt
dumplv
 sysdump    14    14
 1    open/syncd    N/A

Now we need to modify the bosboot to recreate the boot image.

# bosboot –a

Double check your bootlist to make sure hdisk1 is in there.

# bootlist –m normal –o