TheWon's IT Blog

After confirmation from the Application and DBA teams that the application and databases are down the UNIX Administrators need to perform the following steps.
 

1) Remove the alternate i.e.old copy of rootvg altinst_rootvg to free hdisk1
 

2) Add hdisk1 to rootvg
 

3) Mirror the rootvg's hdisk0 with hdisk1
 

4) Create the boot device
 

5) Rebuild the bootlist
 

6) Add hdisk1 and hdisk0 to bootlist and reboot the server to disable the quorum
 

7) Check the status of server and check the boot log for any errors
 

8) Rearrange the bootlist with hdisk0 and hdisk1
 

9) Reboot with hdisk0
 

First complete a status check

Hostname:/:/> lspv
hdisk0          005db36d2f1e67e5                    rootvg          active
hdisk1          005db36d8792541c                    altinst_rootvg    active

Hostname:/> lsvg -p rootvg
rootvg:
PV_NAME           PV STATE          TOTAL PPs   FREE PPs    FREE DISTRIBUTION
hdisk0            active            542         337         109..08..03..108..109

Hostname:/:/> bootinfo -b
hdisk0
Hostname:/:/> lsvg
rootvg
altinst_rootvg
issvg
datavg

 

Now proceed with the activity:

Hostname:/:/> alt_rootvg_op -X altinst_rootvg   #This removes altinst_rootvg   ; hdisk1 is now accessable

 

Bootlist is set to the boot disk: hdisk0

Hostname:/:/> lsvg
rootvg
issvg
datavg

Hostname:/:/> lsvg -o
datavg
issvg
rootvg

Hostname:/:/> lspv
hdisk0          005db36d2f1e67e5                    rootvg          active
hdisk1          005db36d8792541c                    None

Hostname:/> extendvg -f rootvg hdisk1   #Add hdisk1 to rootvg; I had to use the -f force option

Hostname:/> lsvg -p rootvg
rootvg:
PV_NAME           PV STATE          TOTAL PPs   FREE PPs    FREE DISTRIBUTION
hdisk0            active            542         337         109..08..03..108..109
hdisk1            active            542         542         109..108..108..108..109

Hostname:/> mirrorvg rootvg
0516-1124 mirrorvg: Quorum requirement turned off, reboot system for this
       to take effect for rootvg.
0516-1126 mirrorvg: rootvg successfully mirrored, user should perform
       bosboot of system to initialize boot records.  Then, user must modify
       bootlist to include:  hdisk0 hdisk1.
You have mail in /usr/spool/mail/root

Hostname:/> lsvg -p rootvg
rootvg:
PV_NAME           PV STATE          TOTAL PPs   FREE PPs    FREE DISTRIBUTION
hdisk0            active            542         337         109..08..03..108..109
hdisk1            active            542         353         109..24..03..108..109

Hostname:/> 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     32    64    2    open/syncd    N/A
hd8                 jfslog     1     2     2    open/syncd    N/A
hd4                 jfs        1     2     2    open/syncd    /
hd2                 jfs        101   202   2    open/syncd    /usr
hd9var              jfs        12    24    2    open/syncd    /var
hd3                 jfs        24    48    2    open/syncd    /tmp
hd1                 jfs        14    28    2    open/syncd    /home
hd10opt             jfs        2     4     2    open/syncd    /opt
dump_disk0          sysdump    16    16    1    open/syncd    N/A
lv01                jfs        1     2     2    open/syncd    /var/adm/perfmgr

Hostname:/> bosboot -a
Hostname: Boot image is 30577 512 byte blocks.

Hostname:/>  bootlist -m normal hdisk0 hdisk1

Hostname> bootlist -m normal hdisk1 hdisk0

Hostname> reboot

Hostname> bootinfo -b
hdisk1

Hostname:/> alog -o -t boot | less

 

Search for your disk (hdisk1 for me) in the boot log:

Hostname>  bootlist -m normal hdisk0 hdisk1

Hostname> reboot

Hostname> bootinfo -b
hdisk0





http://www.computers-it.com/aix/aix_remirror_rootvg_after_migration_inst.php



 

Default location where AIX copies system dump is page space.

# sysdumpdev -l
primary              /dev/hd6
secondary            /dev/sysdumpnull
copy directory       /var/adm/ras
forced copy flag     TRUE
always allow dump    TRUE
dump compression     ON

# 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     12    24    2    open/syncd    N/A
hd8                 jfs2log    1     2     2    open/syncd    N/A
hd4                 jfs2       1     2     2    open/syncd    /
hd2                 jfs2       19    38    2    open/syncd    /usr
hd9var              jfs2       1     2     2    open/syncd    /var
hd3                 jfs2       5     10    2    open/syncd    /tmp
hd1                 jfs2       1     2     2    open/syncd    /home
hd10opt             jfs2       8     16    2    open/syncd    /opt

This can create a problem since system will not automatically reboot in case of a crash. instead the system will prompt for instructions what to do with the dump. Luckily, it is very easy to change this settings and allocate dedicated logical volume for storing system dump.

First you need to know how big sys dump logical volume should be.

# sysdumpdev -e
Estimated dump size in bytes: 483393536

So, in this case LV should be at least 460MB. If you take a closer look at the logical volume output above, you'll notice that all values in 'PPs' column are twice as big as values in 'LPs' column. That can only mean our root volume group is mirrored. So actually we will need 460MBx2. Let's check if our root volume group has enough free space.

# lsvg rootvg
VOLUME GROUP:       rootvg                   VG IDENTIFIER:  00cb8a0c00004c000000010bfabee774
VG STATE:           active                   PP SIZE:        128 megabyte(s)
VG PERMISSION:      read/write               TOTAL PPs:      542 (69376 megabytes)
MAX LVs:            256                      FREE PPs:       411 (52608 megabytes)
LVs:                8                        USED PPs:       131 (16768 megabytes)
OPEN LVs:           7                        QUORUM:         1
TOTAL PVs:          2                        VG DESCRIPTORS: 3
STALE PVs:          0                        STALE PPs:      0
ACTIVE PVs:         2                        AUTO ON:        yes
MAX PPs per VG:     32512                                     
MAX PPs per PV:     1016                     MAX PVs:        32
LTG size (Dynamic): 256 kilobyte(s)          AUTO SYNC:      no
HOT SPARE:          no                       BB POLICY:      relocatable

Seems that we have 51GB free. More than enough. Also we found out that we have 2 physical volumes in this volume group. Let's check what are the names of this PVs, we will need them soon.

# lsvg -p rootvg
rootvg:
PV_NAME           PV STATE          TOTAL PPs   FREE PPs    FREE DISTRIBUTION
hdisk1            active            271         207         54..29..18..54..52
hdisk2            active            271         204         54..26..18..54..52

Now, what we gonna do is create two logical volumes, one on each PV, and set one as a primary dump device and the other as a secondary dump device. The reason why we do this is that we don't want to mirror sysdump device, but we still need two copies in case one of the hard drives fails.

In this example physical partition is 128MB so we should add 4 PPs to our new logical volumes. Let's start.

# echo $((128*4))
512

# mklv -t sysdump -y sysdump1 rootvg 4 hdisk1
# mklv -t sysdump -y sysdump2 rootvg 4 hdisk2

# 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     12    24    2    open/syncd    N/A
hd8                 jfs2log    1     2     2    open/syncd    N/A
hd4                 jfs2       1     2     2    open/syncd    /
hd2                 jfs2       19    38    2    open/syncd    /usr
hd9var              jfs2       1     2     2    open/syncd    /var
hd3                 jfs2       5     10    2    open/syncd    /tmp
hd1                 jfs2       1     2     2    open/syncd    /home
hd10opt             jfs2       8     16    2    open/syncd    /opt
sysdump1            sysdump    4     4     1    closed/syncd  N/A
sysdump2            sysdump    4     4     1    closed/syncd  N/A

Logical volumes sysdump1 and sysdump2 are created. Now, let's change the system dump settings. First the primary device.

# sysdumpdev -Pp /dev/sysdump1

And now the second.

# sysdumpdev -Ps /dev/sysdump2

Let's check if it's applied.

# sysdumpdev -l
primary              /dev/sysdump1
secondary            /dev/sysdump2
copy directory       /var/adm/ras
forced copy flag     TRUE
always allow dump    TRUE
dump compression     ON

Everything seems fine. All we have to do now is to wait for a system to crash to test our new settings. :o)

http://www.miljan.org/wiki/index.php/How_to_Change_Default_System_Dump_Device_in_AIX 

1. Paging related commands
2. Deactivating paging space
3. Modifying default paging space 
    

Deactivating paging space

Like most modern UNIXes, AIX systems must be rebooted in order to fully deactivate paging space. The full process is as follows:

1. Unset the activation bit for the paging space in question
   chps -a n ${lv}
   
   
2. Ensure the paging space that you are deactivating is not the default dump space. Update the default dump space to something else should that be the case
   

   # sysdumpdev -l
   primary              /dev/dumplv
   secondary            /dev/sysdumpnull
   copy directory       /var/adm/ras
   forced copy flag     TRUE
   always allow dump    TRUE
   dump compression     OFF
   

   sysdumpdev -P -p ${new_dump_dev} # Sets the new dump device
   
   
3. Reboot.
   shutdown -Fr now
   
   
4. Confirm that the target paging space is no longer activated.

   # lsps -a
   Page Space  Physical Volume   Volume Group    Size   %Used  Active  Auto  Type
   paging00    hdisk3            rootvg        4096MB       1     yes   yes    lv
   hd6         hdisk2            rootvg        4096MB       1     yes   yes    lv
   

5. Remove the paging space and logical volume:
   rmps ${lv}

Modifying default paging space

Anytime you're messing with the default paging space (other than increasing the size), you're going to have to supply a temporary default paging space. The checklist that follows shows all the steps required to reduce the size of the default paging lv, hd6.

1. Create a temporary paging space logical volume
   
   mkps -a -n -s 30 rootvg ${disk}
   
   
2. Deactivate hd6 paging space:
   
   chps -a n hd6
   
   
3. Edit /sbin/rc.boot to update the swapon command from hd6 to the name output by the mkps command above (probably /dev/paging00).
   
4. Update, if necessary, the system dump device.
   1. Identify existing dump device by executing sysdumpdev -l
   2. Update by executing sysdumpdev -P -p /dev/paging00
      
5. Update the bootimage with the new paging/dump information by executinngbosboot -d /dev/hdisk0 -a
   
6. Ensure the system key, if present, is in the normal position and reboot the system.
   
7. After the sytem is up, ensure hd6 isn't being used by executing lsps -a
   
8. Remove hd6 by executing rmps hd6
   
9. Create a new hdy by executing mklv -t paging -y hd6 rootvg 30
   
10. Change the dump device back to hd6 by executing sysdumpdev -P -p /dev/hd6
    
11. Edit /sbin/rc.boot to update the swapon command from the temporary to hd6.
    
12. Update the bootimage with the new paging/dump information by executinngbosboot -d /dev/hdisk0 -a
    
13. Activate hd6 by executing chps -a y hd6
    
14. Deactivate the temporary paging space by executing chps -a n paginng00
    
15. Ensure the system key, if present, is in the normal position and reboot the system.
    
16. When the system is back up, remove the temporary paging space by executingnrmps paging00