Basics LVM Administration IBM – AIX Interview Questions

Basics LVM Administration IBM – AIX Interview Questions

Question
Heirarchical relationship between lvm entities ?
Answer
Physcal volume – Volume group – Logical Volume and File system in sequence from Top to bottom
 
Question
Steps to replace one failed rootvg disk in aix ?
Answer
If mirrored in rootvg unmirrorvg (Vgname) ( failedHardisk) reducevg -d (Vgname) (Hardiskname) Add a new hard disk If hot swappable Run cfgmgr -v Add the new hard disk in vg extendvg -f (Vgname) (New Hardisk) mirrorvg (Vgname) (Harddiskname) create bosboot image bosboot -ad /dev/hdiskname set bootlist bootlist -m normal firsthardisk Newharddisk
 
Question
 
How many VGs can be created in a LVM ?
Answer
It depends on the no. of Physical hard disks you have in your operating system
 
Question
With respect to corrupt LVs, if some of the PPs are Stale, then what is the possibility of the data getting corrupt/lost ?
Answer
We can try to copy the corrupted LVs using LVM commands like cplv. If its not possible then we can only do that with the latest backup.
 
Question
For volume group varied on where can we find volume group VGID information.
Answer
 
lsvg (Vgname)
 
Question
Tell me about logform ?
 
Answer
When the size of the log logical volume is changed, the logform command must be run to reinitialize the log before the new space can be used.
 
Question
What is a command to check disk space in AIX ?
Answer
To check gigabyte use df -g in MB use df -m in Kbytes df -k
 
Question
How to identify a hot swap disk in AIX.
Answer
First check the slot which the disk connected in hot-swappable with lsslot -c slot then go to diagostics with diag command and check for fisk its showing then its hot swappable
 
Question
What is the mean by AUTO SYNC in Volume Group.?
 
Answer
AUTO SYNC option if its set yes then whenver there are change made to VG you dont have to run syncvg command. If its disabled or set as NO then everytime changes in VG you have to run syncvg (vgname) to keep ur vg updated.
 
Question
How to use PVG to mirror logical volumes on specific physical volumes
Answer
In LVM there is concept of completely mirroring the complete VG which includes the PVs available into it.In such scenario no sucn to mirror logical volumes on specific physical volumes as per i know.
 
Question
 
What is the filesystem cache concept, how to configure the minimum & maximum value ?
 
Answer
minperm and maxperm can be checked with vmo -a and can be changed vmo -r -o minperm/maxperm=value. Filesystem concept basically used as buffer memory for the filesystem same like paging space to physical memory.
 
Question
What is the relation between LP size & PP size?
Answer
LP is part of logical volume wherein PP is part of physical volume (hard disk) LP = PP in normal case. but in case of mirroring PP’s are doubled than LP
 
Question
What is a command to check disk size in AIX ?
 
Answer
bootinfo -s (diskname)
 
Question
How much we can give the PP size ?
Answer
PP size cant be changed dynamically.We can define PP size only at the time of VG creation
 
Question
 
What is the difference between big, original & scalable volume group?
Answer
NOrmal VG (max 32 PVs) (Max 256 LV) (Max 32512 PPs per VG) (Max PP size= 1GB) Big Vg (max 128 PVs) (Max 512) (Max 32512per VG) (Max PP size= 1GB) Scalable Vg (max 1024) Max 4096)(Max 2097152) (Max PP size= 128 GB)
 
Question
Can we change the LTG size in AIX.if yes pls tell me command to change it ?
Answer
chvg -L (Sie in KB) VGname
 
Question
Mention the behavior of volume group, when quorum is enabled ?
Answer
When Quorum enable you need to have VGDA available more than 51 %. If its not then VG gets offline.
 
Question
 
Explain about T-Factor in AIX ?
Answer
To specify the number of disks and the maximum number of partitions per disk, you use the t-factor.The t-factor is a multiple of 1016.For each t-factor increase, you double the number of physical partitions but cut in half the maximum number of disks allowed in the volume group.