How to add a new disk on Logical Volume Manager (LVM) in AIX Operating System

AIX logical volume manager (LVM) is a widely used tool for logical volume management which includes allocating disks and resizing logical volumes.

Using logical volume manager, a hard disk or set of hard disk is allocated to one or more physical volumes. Logical volume manage (LVM) allows users to create partitions from more than one disk and allows them to extend the filesystem size online within few seconds.

In below text, you can find how to add a new drive in AIX operating system using LVM.

Step by step method to add a new disk on LVM:

➤ Initially we need to add the new physical or virtual disk to the logical partition. After successfully adding virtual disk you need to re scan your server hardware so we can get the new disk information.

For scanning please run the below command on AIX server terminal.

ibm_aix:/> cfgmgr

The command output show you the available new disk which are connected to this AIX machine.

➤ Let’s assume that the new disk is hdisk01,please run the below command to check the disk.

ibm_aix:/> lsdev -Cc disk
hdisk00  Available  Virtual SCSI Disk Drive
hdisk01  Available  Virtual SCSI Disk Drive

In above output two disk is available hdisk00 & hdisk01.

➤ You need to create a new group and move the new disk hdisk01 in there. Let's assume the new group named is "rootvg". So please find the below command to create a new group and add the disk in it.

ibm_aix:/> mkvg -y rootvg hdisk01

in this step we add "hdisk01" into "rootvg".

➤ "lspv" command is used for getting an information about the new disk "hdisk01". Please find the "lspv" command output as given below.

ibm_aix:/> lspv hdisk01
PHYSICAL VOLUME:    hdisk01                   VOLUME GROUP:     rootvg
PV IDENTIFIER:      00f68f03d1e42951 VG IDENTIFIER     00f68f0300004c0000000153d1e429c1
PV STATE:           active
STALE PARTITIONS:   0                        ALLOCATABLE:      yes
PP SIZE:            128 megabyte(s)          LOGICAL VOLUMES:  17
TOTAL PPs:          799 (102272 megabytes)   VG DESCRIPTORS:   2
FREE PPs:           118 (15104 megabytes)    HOT SPARE:        no
USED PPs:           681 (87168 megabytes)    MAX REQUEST:      256 kilobytes
FREE DISTRIBUTION:  11..00..00..00..107
USED DISTRIBUTION:  149..160..159..160..53
MIRROR POOL:        None

If you look the above output you can see the all information regarding the new disk in details.

➤ In this step, you need to create a log logical volume for jfs2 file system and this needs to be part of volume group "rootvg".

ibm_aix:/> mklv -t jfs2log rootvg 1

➤ Please check the new logical volume (lv) and  used the "lsvg" command to check the new logical volume present on the AIX server.

ibm_aix:/> lsvg
rootvg

The command shown you he existing logical group on the server.

ibm_aix:/> lsvg -l rootvg
rootvg:
LV NAME             TYPE       LPs     PPs     PVs  LV STATE      MOUNT POINT
hd5                 boot       1       1       1    closed/syncd  N/A
hd6                 paging     404     404     1    open/syncd    N/A
loglv00             jfs2log    1       1       1    open/syncd    N/A
hd4                 jfs2       4       4       1    open/syncd    /

In above output, you can see "rootvg" is volume group present and in rootvg, you can find the logical volume "loglv00".Now we create a logical volume and fixed their size , lets assume we will used 20GB size and used the logical volume name lv_aix.

ibm_aix:/> lsvg rootvg
ibm_aix:/> mklv -t jfs2 -y lv_aix rootvg 30G
ibm_aix:/> mkfs -o log=/dev/loglv00 -V jfs2 /dev/lv_aix

➤ After successfully create filesystem, we will mount the filesystem to a particular folder.

ibm_aix:/> mkdir /aix
ibm_aix:/> mount -o log=/dev/loglv00 /dev/lv_aix /aix

So, nwly "/aix" filesystem has been created, for permanent it, please make an entry in "/etc/filesystems file. So when you will take a reboot of machine the filesystem not umount.

Please comment on the post, if you have any query regarding this topic.

How to get the SAN Storage Information on AIX Operating System

If you are using IBM AIX Operating System and wants to work on Storage part, then you need understand basic of SAN fiber connectivity with server.

In blog, I would show you all the commands with an example, through which you can get an idea how SAN fiber connect with server and works.

➤ If you want to see how many fiber card (FC) adapter are present on the AIX operating system then please run the below command.

ibm_aix:/> lsdev -Cc adapter | grep fcs

"lsdev" command used for to check the FC adapter present on the IBM AIX servers. In the below line you can find the command output.

ibm_aix:/> lsdev -Cc adapter | grep fcs
fcs0    Available 00-00 8Gb PCI Express Dual Port FC Adapter (df1000f114108a03)
fcs1    Available 00-01 8Gb PCI Express Dual Port FC Adapter (df1000f114108a03)
fcs2    Available 03-00 8Gb PCI Express Dual Port FC Adapter (df1000f114108a03)
fcs3    Available 03-01 8Gb PCI Express Dual Port FC Adapter (df1000f114108a03)

In above command output, you can see on my AIX machine , I have 4 FC card adapter present. Each card adapter have dual port 8Gb. You can see the available adapter name like "fcs0,fcs1". It would be different on every AIX server depend up which type of storage you used.

➤ If you want to check WWN number or SAN ID, please use the below command to check specific information.

ibm_aix:/> lscfg -vl fcs2 | grep "Network Address"
        Network Address.............10000090FAC8D594

In above example, "lscfg" command use to check the all information about a adapter. In my machine , I need an information about WWN  of third adapter "fcs2" which are present on the AIX server. 

This command show you the wwn or SAN ID number which are connected to the server.

➤ If you want to see the fiber card adapter current status, then please use the below command. This command show you regarding the fiber health and all the information regarding the fiber.

ibm_aix:/> fcstat fcs0

FIBRE CHANNEL STATISTICS REPORT: fcs0

Device Type: FC Adapter (adapter/pciex/df1000f114108a0)
Serial Number: 1A550004C1
Option ROM Version: 027820F5
ZA: U2D2.03X5
World Wide Node Name: 0x20000090FACA86B4
World Wide Port Name: 0x10000090FACA86B4

Output of this command "fcstat" is very long so I can not write here, you can run this command on your AIX platform and check all the information. 

Please post your comment on this blog, if you have any query regarding this topic. I will try to resolve your query as earliest.