| Question |
| Heirarchical relationship between lvm entities ? |
| Answer |
| Physcal volume – Volume group – Logical Volume and File system in sequence from Top to bottom |
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| 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 |
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| Question |
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| 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 |
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| 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. |
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| Question |
| For volume group varied on where can we find volume group VGID information. |
| Answer |
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| lsvg (Vgname) |
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| Question |
| Tell me about logform ? |
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| 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. |
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| 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 |
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| 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 |
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| Question |
| What is the mean by AUTO SYNC in Volume Group.? |
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| 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. |
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| 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. |
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| Question |
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| What is the filesystem cache concept, how to configure the minimum & maximum value ? |
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| 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. |
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| 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 |
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| Question |
| What is a command to check disk size in AIX ? |
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| Answer |
| bootinfo -s (diskname) |
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| 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 |
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| Question |
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| 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) |
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| 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 |
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| 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. |
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| Question |
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| 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. |
