lsjfs2 /mymntpt
dumpfs /mymntpt

<box 100% round orange|PHYSICAL VOLUME (PV)>Represents a hard disk (hdisk0).</box>

<box 100% round blue|PHYSICAL PARTITION (PP)>The smallest allocation unit in the LVM. All PPs within a VG are the same size, usually 4 or 8 MB.</box>

<box 100% round orange|VOLUME GROUP (VG)>A set of one or more PVs which form a single storage pool. You can define multiple VGs on each AIX system.</box>

<box 100% round blue|LOGICAL VOLUME (LV)>One or more PPs. A file system resides on top of an LV. Only one LV is mapped to a file system. A LV can't span across multiple VG. Up to 255 LVs in a VG</box>

LOGICAL PARITITION (LP)

One or more PPs. LP represents a mirrored copy of a PP. Up to two copies of a PP can be mirrored 
resulting in a LP count of three (2 mirrors plus original).

Volume Group Descriptor Area (VGDA)

Information about all the LVs and PVs within a VG. The first 64K of a PV is reserved for this area 
- defined in <sys/bootrecord.h>.

The VGDA consists of

BOOTRECORD: - first 512 bytes. Allows the Read Only System (ROS) to boot system
BAD BLK DIRECTORY - found in <sys/bddir.h>
LVM RECORD - found in <lvmrec.h>

Volume Group Status Area (VGSA)

Information about which PPs that are stale and which PVs are missing within a VG. The LVM and SCSI 
driver reserves somewhere between 7-10% of the available disk space for LVM maps, etc.

Physical Volume ID (PVID)

The PVID is an amalgamation of the machine’s serial number (from the systems EPROMs) and the date that 
the PVID is being generated. This combination insures theextremely low chance of two disks being created
with the same PVID. Finally, when a system is booted, the disk configurator goes and looks at the PVID 
sitting on each disk platter and then compares that to an entry in ODM. If the entry is found, then 
the disk is given the hdiskX name that is associated with the ODM entry for the PVID.

Quorum

Quorum is a sort of “sanity” check that LVM uses to resolve possible data confliction and prevent data 
corruption. Quorum is a method by which 51% or more quorum votes must be available to a volume group 
before LVM actions can continue. Quorum is issued to a disk in a volume group according to how the 
disk was created within the volume group. When a volume group consists of one disk, there are two 
VGDA’s on that disk. Thus, this single disk volume group has a quorum vote of 2. When another disk is 
added to the volume group with an “extendvg”, then this new disk gets one VGDA, but the original, first 
disk still retains the two VGDA’s. When the volume group has been extended to three disks, the third 
disk gets the spare VGDA sitting on the first disk and then each disk has a quorum vote of 1. Every 
disk after the third disk is automatically given one VGDA, and thus one vote.

Volume Group ID (VGID)

Just as the PVID is a soft serial number for a disk, the VGID is the soft serial number for the volume
group. It is this serial number, not the volume group’s ascii name, which all low level LVM commands 
reference. Additionally, it is the basis for the LVIDs created on that VGID.

Logical Volume Control Block (LVCB)

The logical volume control block (lvcb) consists of the first 512 bytes of a logical volume. This area 
holds important information such as the creation date of the logical volume, information about mirrored
copies, and possible mount points in a journaled filesystem.

Logical Volume ID (LVID)

The LVID is the soft serial number used to represent the logical volume to the LVM libraries and low 
level commands. The LVID is created from the VGID of the volume group, a decimal point, and a number 
which represents the order which the logical volume was created on the volume group.

diagnostic

diag - used to hot swap the disk
cfgmgr - used mak sure the new disk is seen

to add new disk from the scsi0 controller

cfgmgr -l scsi0
Create/Remove hard disk 	cfgmgr -l scsi0
mkdev -c disk -l <pv>
rmdev -dl <pv>
Physical Volumes
display 	lspv
lspv <pv>           (detailed)
lspv -l <pv>        (list logical volumes)
lspv -p <pv>       (physical partition usage)
PVID 	chdev -l <pv> -a pv=yes
chdev -l <pv> -a pv=clear

Note: PVID's are automatically added when the disk is placed into a vg
adding 	chdev -l <pv> -a pv=yes    (new)
chpv -v a <pv>                 (adds back the removed disk)
removing 	chpv -v r <pv>
change physical attributes 	chpv -a y <pv>                (changes allocatable state to YES)
chpv -a n <pv>                (changes allocatable state to NO)

moving 	migratepv <old pv> <new pv>

display 	lsvg

lsvg <vg>           (detailed)
lsvg -l <vg>        (list all logical volumes in goup)
lsvg -p <vg>       (list all physical volumes in group)
lsvg -o              (lists all varied on)
lsvg -M <vg>       (lists assicated disks and state)

## Details volume group info for the hard disk

lqueryvg -Atp <pv>
lqueryvg -p <disk> -v                 (Determine the VG ID# on disk)
lqueryvg -p <disk> -L                 (Show all the LV ID#/names in the VG on disk)
lqueryvg -p <disk> -P                 (Show all the PV ID# that reside in the VG on disk)

varyon / activate a volume group

varyonvg <vg>
varyonvg -f <vg>    (force)
varyonvg -s <vg>    (maintenance mode can use VG commands but lv 's cannot be opened for i/o access)
varyoffvg <vg>

Note: the varyon command activiates the volume goup which means it is available for use

ODM related ## Determine if the ODM and VGDA are correct (in sync)

getlvodm -u <vg>

## tries to resync VGDA, LV control blocks and ODM

synclvodm <vg>

## If the message 0516-366 lsvg: Volume group <vg> is locked is ever seen

putlvodm -K `getlvodm -v <vg>`
creating 	mkvg -y <vg> -s <PP size> <pv>

Check volume group type (normal, big,scalable):

 [root@aix01]/root# readvgda hdisk6  | grep readvgda_type
.....    readvgda_type: smallvg

[root@aix01]/root# readvgda hdisk5 | grep readvgda_type
.....    readvgda_type: bigvg

[root@aix01]/root# readvgda hdisk8 | grep readvgda _type
.....    readvgda_type: svg

mkvg -y datavg -s 4 hdisk1

Note: the PP size will be the size of the physical partition size you want 4MB, 8MB

extending 	extendvg <vg> <pv>
reducing 	reducevg -d <vg> <pv>

## removes the PVID from the VGDA when a disk has vanished without using the reducevg command

reducevg <vg> <PVID>

removing

varyoffvg <vg>
exportvg <vg>

Note: the export command nukes everything regardingthe volume goup in the ODM and /etc/filesystems checking

## check to see if underlying disk has grown in size

chvg -g <vg>

Note: use this command if you are using SAN LUN's that have increased in size change volume attributes ## auto vary on a volume at system start

chvg -a y

# Turns on/off quorum checking on a volume group

chvg -Q [y|n] <vg>

renaming

varyoffvg <old vg name>
lsvg -p <old vg name>                     (obtain disk names)
exportvg <old vg name>
import -y <new vg name> <pv>
varyonvg <new vg name>
mount -a

importing

importvg -y <vg> <pv>
importvg <pv>                     (will use rootvg as default vg)

exporting

varyoffvg <vg>
exportvg <vg>

Note: if the volume has an active paging space this must be turned off before

Logical Volumes display

lslv <lv>
lslv -l <lv>           (list all physical volumes in logical volume)
lslv -m <lv>          (list ppartition mapping)

## Display lv control block information

getlvcb -AT <lv>

creating

mklv <vg> <# of PP's> <pv>
mklv -y <lv name> <vg> <# of PP's> <pv>

## Create a mirrored named logical volume

mklv -y <lv> -c <copies 2 or 3> <vg> <# of PP's> <pv>

## create a JFSlog logical Volume

mklv -y <lv name> -t jfslog <vg> <# of PP's> <pv>

extending

extendlv <lv> <additonal # of PP's>
extendlv <lv> <size of volume in B||M|G>

reducing/resizing see filesystem below

removing

rmlv <lv>

moving

migratepv -l <lv> <old pv> <new pv>

adding a mirror to a non-mirrored volume

mklvcopy -s n <lv> <copies 2 or 3> <pv>

removing a mirror copy from a mirrored volume

rmlvcopy <lv> <copies 1 or 2>
rmlvcopy <lv> <copies 1 or 2> <pv>      (specified pv)

synchronize logical volume

syncvg -p <pv>
syncvg -v <vg>
syncvg -l <lv>

mirror any unmirrored volumes

mirrorvg <vg> <pv>
unmirrorvg <vg> <pv>

change volume attributes ## Enable the bad-block relocation policy

chlv -b [y|n] <lv>

renaming

chlv -n <new lv name> <old lv name>

Miscellaneous ## Initialises an LV for use as an JFSlog

logform </dev/lv>

Display filesystems

lsfs -a
lsfs -q <fs>      (detailed)

[root@aix1]/root# lsfs -q
Name            Nodename   Mount Pt               VFS   Size    Options    Auto Accounting
/dev/hd4        --         /                      jfs2  4194304 --         yes  no
  (lv size: 4194304, fs size: 4194304, block size: 4096, sparse files: yes, inline log: no, inline log size: 0, EAformat: v1, Quota: no, DMAPI: no, VIX: yes, EFS: no, ISNAPSHOT: no, MAXEXT: 0, MountGuard: no)
/dev/hd1        --         /home                  jfs2  1048576 --         yes  no
  (lv size: 1048576, fs size: 1048576, block size: 4096, sparse files: yes, inline log: no, inline log size: 0, EAformat: v1, Quota: no, DMAPI: no, VIX: yes, EFS: no, ISNAPSHOT: no, MAXEXT: 0, MountGuard: no)

[root@aix1]/root# lsjfs2

#MountPoint:Device:Vfs:Nodename:Type:Size:Options:AutoMount:Acct:OtherOptions:LvSize:FsSize:BlockSize:Sparse:InlineLog:InlineLogSz:EAformat:Quota:DMAPI:VIX:EFS:ISNAPSHOT:maxext:MountGuard
/:/dev/hd4:jfs2::bootfs:4194304:rw:yes:no::4194304:4194304:4096:yes:no:0:v1:no:no:yes:no:no:0:no:
/home:/dev/hd1:jfs2:::1048576:rw:yes:no::1048576:1048576:4096:yes:no:0:v1:no:no:yes:no:no:0:no:
/usr:/dev/hd2:jfs2::bootfs:6684672:rw:yes:no::6684672:6684672:4096:yes:no:0:v1:no:no:yes:no:no:0:no:
/var:/dev/hd9var:jfs2::bootfs:4194304:rw:yes:no::4194304:4194304:4096:yes:no:0:v1:no:no:yes:no:no:0:no:

Note: use the '-q' to see if the logical volume size is bigger than the filesystem size create ## create new filesystem, -A means to mount after restart

crfs -v jfs -d <lv> -m <mountpoint> -A yes -a log=INLINE

## Create logical volume, filesystem, mountpoint, add entry to /etc/filesystems at the specified size

crfs -v jfs2 -g <vg> -m <mountpoint> -a size=<size in 512k blocks|M|G) -A yes

Note: there are two types of filesystems jfs and jfs2, jfs2 allows you to decrease the filesystem size , you cannot reduce a jfs filesystem remove

rmfs <fs>

Note: if all filesystems have been removed from a logical volume then the logical volume is removed as well.

Resize a filesystem

chfs -a size=<new size> <fs>

chfs -a size=1G /var        (specific size, can be used to increase and decrease)
chfs -a size=+1G /var      (increase by 1GB)
chfs -a size=-1GB /var     (reduce by 1GB)

Note: this will automatically increase or decrease the underlying logical volume as well freeze/unfreeze chfs -a freeze=<time in seconds> <fs> chfs -a freeze=off <fs> split mirrored copy chfs -a splitcopy=<split copy mountpoint>-a copy=2 <fs>

chfs -a splitcopy=/backup -a copy=2 /testfs change ## Change the mountpoint chfs -m <new mountpoint> <fs>

## Do not mount after a restart chfs -A no <fs>

## Mount read-only chfs -p ro <fs> mount mount mount [<fs>|<lv>] mount -a mount all defrag defragfs -q <fs> (report defrag status) defragfs -r <fs> (runs in report only mode - no action) defragfs <fs> (actually defrags the filesystem) checking and repairing fsck [-y|-n] <fs> (check a filesystem) fsck -p <fs> (restores primary superblock from backup copy if corrupt) Miscellaneous Complete VG, LV and FS with mirroring example

## Create the volume group mkvg -s 256 -y datavg hdisk2

## Create the jfs2 log logical volume and initialize it this for the volume group mklv -t jfs2log -y dataloglv datavg 1 logform /dev/dataloglv

## Create the logical volume mklv -t jfs2 -y data01lv datavg 8

## Create the filesystems that will use the logical volume crfs -v jfs -d data01lv -m /data01 -A yes

## Add an additional hard disk to the volume group extendvg datavg hdisk3

## Now mirror both the volume group log logical volume and the logical volume mklvcopy dataloglv 2 mklvcopy data01lv 2

## Make sure everything is sync'ed both the log and the logical volume syncvg -v datavg

## Make sure everything is OK lsvg -l datavg

## a quick way to perform the above in two steps mklv -c 2 -t jfs2 -y data02lv datavg 8 crfs -v jfs -d data02lv -m /data02 -A yes

## mount everything and check mount -a Replaced failed mirror drive ## break the mirror (two ways to do this) rmlvcopy <lv name> 1 <broken disk> unmirrorvg <lv> <broken pv >

## remove the disk from the vg reducevg <vgname> <broken pv >

## remove the hdisk from ODM rmdev -dl <broken pv>

## physically replace the disk diag → function select → task selection → hot plug task → scsi and scsi raid hot plug manager → replace/remove a device attached to an scsi hot swap enclosure device → select disk and follow instructions

## configure new disk an check the new number (hopefully the same) cfgmgr -v lsdev -Cc <pv>

## add back to volume group extendvg <vg> <pv>

## create mirror (two ways to do this) mklvcopy <lv> 2 <pv> mirrorvg <lv>

## sync mirror syncvg -l <lv>

## If this is the rootvg there are additonal steps to take bosboot -ad /dev/<pv> bootlist -m normal <pv> <pv> bootlist -m normal -o Accidently remove a mirrored disk or SAN LUN disappeared off the network

## This procedure places back a mirror disk that you have accidently pulled or that a SAN LUN disappeared off the network ## and its states is classed as “missing”

## see that the disk is in a missing state (see PV state column), also see stale volumes lsvg -p <vg> lsvg -M <vg>

## To make the disk active again we use the varyonvg command varyonvg <vg>

## see that the disk is in a active state (see PV state column) lsvg -p <vg>

## Now re-sync the volumes in that volume group syncvg -v <vg>

## Make sure that no volumes are stale lsvg -M <vg>

## Determine if the ODM and VGDA are correct (in sync) getlvodm -u <vg>

[root@labo]/root# /usr/sbin/defragfs -q /mksysb
Total allocation groups                                            : 65
Allocation groups skipped - entirely free                          : 26
Allocation groups skipped - too few free blocks                    : 35
Allocation groups that are candidates for defragmenting            : 4
Average number of free runs in candidate allocation groups         : 206
[root@labo]/root# /usr/sbin/defragfs -r /mksysb
Total allocation groups                                            : 65
Allocation groups skipped - entirely free                          : 26
Allocation groups skipped - too few free blocks                    : 35
Allocation groups that are candidates for defragmenting            : 4
Average number of free runs in candidate allocation groups         : 206
[root@labo]/root# /usr/sbin/defragfs /mksysb
Defragmenting device /dev/mksysblv.  Please wait.

Total allocation groups                                            : 65
Allocation groups skipped - entirely free                          : 25
Allocation groups skipped - too few free blocks                    : 35
Allocation groups defragmented                                     : 5

defragfs completed successfully.

Total allocation groups                                            : 65
Allocation groups skipped - entirely free                          : 25
Allocation groups skipped - too few free blocks                    : 35
Allocation groups that are candidates for defragmenting            : 5
Average number of free runs in candidate allocation groups         : 165

VGDA – Volume Group Descriptor Area – describes the VG (Volume Group) layout, at least one copy on each disk in a VG

Best to save this before running VG related commands in case of a failure:

• Small VG:

dd if=/dev/hdiskX of=/tmp/hdiskX.vgda bs=128K count=17

• Big VG:

dd if=/dev/hdiskX of=/tmp/hdiskX.vgda bs=128K count=71

• SVG(Scalable):

dd if=/dev/hdiskX of=/tmp/hdiskX.vgda bs=512K count=137

http://www.datadisk.co.uk/html_docs/hp/aix_lvm.htm

[root@nim001]/root> for i in $(lsvg | grep -v rootvg)
do
echo "#### $i";readvgda $(lspv | grep -v rootvg | awk '{print $1,$3}' | grep $i | head -1 | awk '{print $1}' ) | grep readvgda_type

done

#### nimavg
.....    readvgda_type: svg
#### softavg1
.....    readvgda_type: smallvg
#### mksysbavg
.....    readvgda_type: svg
#### gpfsbkpvg
.....    readvgda_type: bigvg
#### testvg
.....    readvgda_type: smallvg

VGDA contains VGID, list of LV, quorum, …

[root@nim001]/root> readvgda hdisk5
vg_id:          00fa343b00004c00000001609c177ef5
numlvs:         20
maxlvs:         256
pp_size:        27
numpvs:         2
total_vgdas:    3
vgda_size:      2098
vgtype:         0
quorum:         0
auto_varyon:    1