Il peut arriver que des hdisk autrefois alloués à un VG et à une baie de disques soient conservés avec le vieux PVID, même s'ils apparaissent 'Available' pour le nouveau stockage.
Si le disque est vide ou au contenu pouvant être écrasé, il est simple de faire un 'chdev -l hdiskX -a pv=clear' pour effacer le PVID du disque. Lors de sa prochaine utilisation, le PVID sera redéfini.
Les opérations décrites ci-dessous expliquent comment vérifier les PVID et les récupérer.
Personnellement, je préfère utiliser la commande 'chdev -a pv=yes -l hdiskX' pour essayer de récupérer le bon PVID, plutôt que de faire du 'dd'.
Mais si cette méthode ne fonctionne pas, il reste toujours cet essai...
Sur le disque hdisk405 par exemple:                                                      
 
Le PVID devrait être:                                                             
 
00c4bcc0d4e5f703                                                              
 
Il peut être lu par la commande :                                 
 
lquerypv -h /dev/hdisk405 80 10 
 
 
 
L'information stockée dans la  VGDA peut être:                              
 
00c4bcc03f0d0d8e                                                              
 
et contrôlée par la commande                                               
 
readvgda -v3 hdisk405                                                         
Ci-dessous une solution officielle IBM, mais qui fait peur(dd) ou qui nécessite une fermeture du VG.
The pvid in the                                                               
vgda must be the same as the pvid of the disk, that is why there are 2        
possibilities:                                                                
1. change the PVID on the hdiskxxx to be identical with the one in the        
VGDA or                                                                       
2. change the value stored in the VGDA for that disk to be the PVID           
 
For option 1.                                                                 
Execute the following script in order to change manually the PVID on          
the disk, the value being the one displayed in the VGDA.                      
 
Chpvid sets the pvid on a disk to a given value. This was useful in buil      
examples for this book and may be of use as a last resort in recovery         
situations.                                                                   
Syntax: chpvid                                                                
 
 
 
You can find more information about this script at the link:                  
 
AIX Logical Volume Manager from A to Z: Troubleshooting and                   
Commands                                                                      
 
http://www.redbooks.ibm.com/abstracts/SG245433.html?Open                      
 
In Appendix E2.                                                               
 
 
 
 
Flags: none                                                                   
 
Note: It is most strongly recommended that the chpvid script is not used      
as a production tool in a production environment, as its effects are          
undefined. IBM will not be held responsible if you use this tool.             
 
Syntax: chpvid (new pvid) (hdisk)                                             
 
Flags: None                                                                   
 
#!/usr/bin/ksh                                                                
pvid=$1                                                                       
disk=$2                                                                       
set -A a `echo $pvid|\                                                        
awk ' {                                                                       
for (f=1; f <= length($0); f=f+2) {                                           
print "ibase=16\nobase=8\n"toupper(substr($0,f,2))                            
}                                                                             
}'|\                                                                          
bc 2>/dev/null`                                                               
/usr/bin/echo "\0"${a[0]}"\0"${a[1]}"\0"${a[2]}"\0"${a[3]}"\0"\               
${a[4]}"\0"${a[5]}"\0"${a[6]}"\0"${a[7]}"\0\0\0\0\0\0\0\0\c"|\                
dd bs=1 seek=128 of=/dev/$disk                                                
 
 
 
For option 2.                                                                 
 
recreatevg -y dwhilogvg  -Y NA -L / hdisk405 hdisk406 hdisk407 hdisk408       
hdisk409 hdisk410 hdisk411 hdisk412 hdisk413 hdisk414 hdisk415 hdisk416       
hdisk417 hdisk418
 
                    
