How to add a disk on AIX Logical Volume Manager (LVM)

In the last post of AIX, I had explained that how we create a logical volume manager on AIX operating system. In this post, I will explain to you how to add a disk on AIX logical volume manager.

LVM (Logical Volume Manager) is a tool for logical volume management which includes allocating disks, striping, mirroring and resizing logical volumes.With LVM, a hard drive or set of hard drives is allocated to one or more physical volumes.

LVM allows users to create partitions from more than one disk and allows them to extend the filesystem size online within few seconds.

Step by step method to add a disk on LVM.

1. In the first step we will add the physical or virtual disk to the logical partition. Once the new disk is added on the logical partition then we can able to go for next step.

2. Now, rescan your system hardware so that the Operating system can find which new hard disk is add on the server. For this please use the below command to scan the hardware on AIX operating system.

aix:/> cfgmgr

3. In this step, we will check the disk. For example, let’s assume that the new disk is hdisk1, so please run the below command to check the disk.

aix:/> lsdev -Cc disk

hdisk0  Available  Virtual SCSI Disk Drive

hdisk1  Available  Virtual SCSI Disk Drive

aix:/> lspv

hdisk0      00f68f03d1e42951       rootvg          active

hdisk1      00f68f03d20beafd       vstorage        active

hdisk2      00f68f03d20ceb37       vstorage        active

if you see the above both output, you can found that hdisk1 is available to add on Voulme group.

4. In this step, now you need to create a new group and move the new disk hdisk1 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.

aix:/> mkvg -y rootvg hdisk1

5. Now you can look at the size of hdisk1. Please run the below command , you can found the below output regarding the disk space of your disk and this command would not work if it is not associated with the volume group.

aix:/> lspv hdisk1

PHYSICAL VOLUME:    hdisk1                   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

6. In this step , now we will create a log logical volume for jfs2 file system and this needs to be part of vloume group "rootvg".

aix:/> mklv -t jfs2log rootvg 1

As i can not paste the my machine output as I am already add it, You can add at your end , if any issue occur on this stage please comment on the post.

7. Now, we will check the new logical volume (lv) and you can used the below command to check the new logical volume present on the AIX server.Normally on AIX server we are used "loglv00" logical name, as on my machine I used the same name.

aix:/> lsvg

rootvg

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    /

If you see the above both the output, you can find that "rootvg" is voulme group present and in rootvg, you can find the logical volume "loglv00".

8. In this, we will create a logical volume and fixed their size , lets assume we will used 30GB size and used the logical volume name lglv_test.

aix:/> lsvg rootvg

aix:/> mklv -t jfs2 -y lglv_test rootvg 30G

aix:/> mkfs -o log=/dev/loglv00 -V jfs2 /dev/lglv_test

9. In the seconf last step we will mount the newly created file system on the AIX operating system.

aix:/> mkdir /test

aix:/> mount -o log=/dev/loglv00 /dev/lglv_test /test

In this example , we will create a "/test" file system and mount the file system on this folder.

10. In the final step we will make a permament entry of this file system in "/etc/filesystems file so once you take a reboot of AIX server, file system will mount permamently, otherwise you need to mount again if you not made an entry in /etc/filesystems.

Hope this post is useful for you, as this step by step method you can not found in other sites, In case still you are facing any issue related to this topic, please comment on this post, I will revert to you with solution.

How to find the console IP address in HP-UX Servers

In this post, I will guide you to how to find the console IP address in HP-UX operating system if we lost or forgotten. So here, I will provide you the simple steps to get back the console IP address of HP-UX system.

For Itanium systems running 11.31 version only we can use smh and the cprop command. These both method works to recover the forgotten password.

cprop is what the smh webpage uses to retrieve the IP address. Run the smh webpage (hostname:hpx)

Home -> System -> Management Processor

It is show you the IP address of console port. Also please find the below "cprop" command usage, how to we run this command.


hpx:/>/opt/propplus/bin/cprop -summary -c “Management Processor”

[Component]: Management Processor
[Table]: Management Processor
——————————————————-
****************************************************
                   [Hash ID]: Management Processor:11a64d1ax41eed6da
                    [Status]: OK
                 [IPAddress]: 192.168.1.23
                       [URL]: https://192.168.1.23
                     [State]: Enabled
****************************************************

For PARISC boxes and Itanium models running 11.23 or earlier, you must use the serial port on the back of the box. The commands will be:

ctrl-a (to get the attention of the console interface)
<login> typically Admin and Admin
CM (to get to the command menu)
LC
MA (to exit the CM menu)
X  (to exit the GSP or MP menu)

You need to connect a serial cable on Serial port of the HP-UX server and connected to own laptop. Once you will get the ssh or telnet session from serial connection, you need to run the above command to get the IP address of HP-UX console.

Sometimes the serial port is not working then in this case you need to login in serial management port of the server and recover the IP address again.

Please revert back if you are encounter any issue related to this post.

How to find the boot disk from HP-UX operating system

In this article , I would explain to you how we find which disk are used to boot the running HP-UX operating system. This is a bit tricky because its depending on the version of HP-UX, and whether it is using LVM or the less common choice.

For LVM disk layouts:

For 11.11 and earlier, use the below command to check which disk is in used.

# echo “boot_string/S” | adb -k /stand/vmunix /dev/kmem

    boot_string:

    boot_string:    disk(0/0/2/0.6.0.0.0.0.0;0)/stand/vmunix

For 11.23, there are different ways for PARISC versus IA64:

PARISC:

# echo “boot_string/S” | adb -o /stand/vmunix /dev/kmem

    boot_string:

    boot_string:    disk(1/0/0/3/0.6.0.0.0.0.0;0)/stand/vmunix

IA64 (Itanium/Integrity):

# echo “bootdev/x” | adb -n /stand/vmunix /dev/kmem

    bootdev:

        0x100001c

Now to find the actual path, you’ll have to match the 0x100001c value to a minor number in the /dev/disk directory. Compare only the last 6 digits of the number (00001c) to find the device file. Then by using lssf, you can decode the hardware path:

    # DSK=$(ll /dev/disk | awk ‘/00001c/{print $NF}’)

    # echo $DSK

    disk11_p2

    # HWPATH=$(lssf /dev/disk/$DSK | awk ‘{print $(NF-1)}’)

    # echo “$DSK path = $HWPATH”

    disk11_p2 path = 64000/0xfa00/0xa

You can also use ioscan -m dsf to map agile device file names to legacy (CTD) style.

For VxVM disk layouts:

# echo “raw_root/X” | adb -o /stand/vmunix /dev/kmem

     raw_root:

     raw_root:       0x3000002

This value is the minor number for the disk that was used to boot the current system. The minor number is found in the /dev/vx/dmp directory.

     # DSK=$(ll /dev/vx/dmp | awk ‘/000002/{print $NF}’)

     # echo $DSK

    c2t1d0s2

     # HWPATH=$(lssf /dev/dsk/$DSK | awk ‘{print $(NF-1)}’)

     # echo “$DSK path = $HWPATH”

     c2t1d0s2 path = 0/1/1/0.1.0

For completeness, I should mention that 11.31 will report the boot disk path in syslog.log (LVM or VxVM) like this:

vmunix: Boot device’s HP-UX HW path is: 0/1/1/0.0×1.0x0

However, syslog.log is a catch-all for a lot of items and often needs to be truncated when it grows too large. As a result, it can’t be relied on to always contain the current boot disk.

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Hello Friends,

In this post, I would explain to you how to resolve one of the most intreseting issue on linux servers "Kernel Panic". I think the linux lovers much awaited such issue while they are working on Unix troubleshooting part.

As everyone knows Kernel are most importent part of any operating system and if it is crashed that's means your system crashed.

Normally kernel panic occur when you upgrade the server or upgrade the packages on the server. Here, you can find one of the Kernel panic issue as describe below.

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Pid: 1, comm: swapper Not tainted 2.6.32-502.el6.x86_64 #1

Call Trace:

 [<ffffffff815292bc>] ? panic+0xa7/0x16f

 [<ffffffff81c2b432>] ? mount_block_root+0x216/0x2cb

 [<ffffffff81002930>] ? bstat+0x2b0/0x980

 [<ffffffff81c2b53d>] ? mount_root+0x56/0x5a

 [<ffffffff81c2b6b1>] ? prepare_namespace+0x170/0x1a9

 [<ffffffff81c2a92a>] ? kernel_init+0x2e1/0x2f7

 [<ffffffff8100c20a>] ? child_rip+0xa/0x20

 [<ffffffff81c2a649>] ? kernel_init+0x0/0x2f7

 [<ffffffff8100c200>] ? child_rip+0x0/0x20

Solution : Normally this issue occur while you upgrade your server using yum and after reboot server is not boot due to kernel panic problem. This problem occur while kernel version has not been changed properly.

You can boot your linux server in grup mode and check the kernel and initrd paramtere. Match both the parameter if they are using same kernel version. During upgrade the initrd version normally not changed so you can manually change the correct kernel version entry in this file.

Once you modified the initrd files boot the server and make a same changes in grub.conf file too, otherwise once you take a reboot or shutdown the machine same kerenl panic error will occur.

[root@localhost]# vi /etc/grub.conf

#boot=/dev/sda

default=0

timeout=5

splashimage=(hd0,0)/grub/splash.xpm.gz

hiddenmenu

title CentOS 6 (2.6.32-504.el6.x86_64)

        root (hd0,0)

        kernel /vmlinuz-2.6.32-504.el6.x86_64 ro root=/dev/mapper/vstorage-root rd_NO_LUKS LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vstorage/root  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

        initrd /initramfs-2.6.32-504.el6.x86_64.img

In above example, the default value 0 identifies the first title option to be used as default, the corresponding kernel version in title option line as 2.6.32-504.el6.x86_64 and the initramfs image file as initramfs-2.6.32-504.el6.x86_64.img. 

Before changing thing please take a backup of grub.conf file. now you can rename the kernel version in the initrd line and matched the same version at both the line and reboot the server, after reboot your linux machine will boot normally.

Hope your kernel panic issue will be resolved after reading this post. Please let me know if you are still facing this issue, I would try to help you.

How To Fix “Device eth0 does not seem to be present, delaying initialization” Error

This Ethernet card error is normally occur on Linux operating system like CentOS, Red Hat Linux etc. When you try to up the Ethernet card it is showing you the above topic error.

So in this post, we will provide you the step by step solutions and troubleshoot all the issue related this error.

In the initial step, you will check which Ethernet card is down , for this you can run the "ifconfig -a" command. Using this command you can check how many internet card is present on the server and on which Ethernet card used IP address.

Let's suppose you are using eth0 on your machine, and if this Ethernet card not taking any ip address and now show on your device that means it is down right now, so please try to start Eth0 device as given below command.

[root@localhost]# ifup eth0

Device eth0 does not seem to be present, delaying initialization

If your internet card show such issue that means you have an issue with MAC address. So in this post I would explain you how to resolve such issue.

1. In this step, please check the MAC Addresses are set correctly or not. For checking this you need to go the network card directory "/etc/sysconfig/network-scripts"

[root@localhost]# cd /etc/sysconfig/network-scripts

[root@localhost]# cat ifcfg-eth0

HWADDR=”00:15:5D:00:91:91”

In the configuration file, you can see the current hardware address of eth0 card, I have show you only HWADDR entry of my eth0 file. In this directory you can see if other Ethernet card is present or not. In my Linux machine i have two Ethernet card , please find the below second Ethernet card MAC address.

[root@localhost]# cat ifcfg-eth1

HWADDR=”00:15:5D:00:91:90”

2. Now we will see which link is present on the system currently and which is not active, for this you can use the below command to check the status.

[root@localhost]# ip -o link

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN \    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000\    link/ether 00:15:5D:00:91:90 brd ff:ff:ff:ff:ff:ff

3: eth2: mtu 1500 qdisc   pfifo_fast state UP qlen 1000\ link/ether 00:15:5D:00:91:91 brd ff:ff:ff:ff:ff:ff

Here, no eth1 but there is an eth2 present on the system, so might be problem is that the eth0 is renamed to eth2 but we will confirm with below command.

[root@localhost]# dmesg | grep eth0

udev: renamed network interface eth0 to eth2

udev: renamed network interface rename3 to eth0

From this command it shows that udev rename the network interface, so in the next step we will remove the wrong entry and configure the Ethernet card 

3. Now please open the network rules file to confirm the mac address. Please open this file "/etc/udev/rules.d/70-persistent-net.rules" 

[root@localhost]# cat /etc/udev/rules.d/70-persistent-net.rules

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:90", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:91", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:91", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

Looks like there are multiple entries for the same MAC address. Removed the incorrect entry and restart the interface using below command.

[root@localhost]# ifup eth0

Now you eth0 card is up and if you are running "ifconfig -a" command you can see the eth0 card with mac address. 

Hope you are get the solution of the above issue, also please let me know if you have any other issue.

How to Configure Proxy Settings in Linux

In this post, I will explain , how we set or configure the proxy setting in Linux server. Usually when you work on the cooperate server you work behind the proxy. So if you are trying to download any packages or software on the Linux operating system machine, you need to configure the proxy on your browser or on system profile.

1. If you want to set http_proxy shell variable on Linux terminal or bash shell, then please use the below command or method to set the proxy settings on terminal.

# export http_proxy=http://Proxy_IP:Proxyport

or

# export http_proxy=http://Proxy_Domain:ProxyPort

You can use above command to set the proxy on bash shell or on terminal. You can use Proxy IP as well as Proxy DNS name to configure the proxy on shell. In my case I have use proxy IP on my server.

#export http_proxy=http://192.168.1.70:8080

If you want to use https proxy then please run the below command to set the proxy settings on bash or any other shell.

#export https_proxy=https://Proxy_IP:ProxyPort

or

#export https_proxy=https://Proxy_Domain:ProxyPort

You can use this proxy on open shell only if you close the terminal or shell then you need to set proxy variable again.

If your proxy use authentication then you need to give proxy user name and password while you are running the above command.

#export http_proxy=http://Proxy_User:Proxy_Password@Proxy_IP:Port

2. If you want to setup proxy variable for all users then you need to set proxy environment as a global variable. To do this you need to set proxy variable on /etc/profile file.

# vi /etc/profile

export http_proxy=http://Proxy_IP:Proxyport

or

export http_proxy=http://Proxy_User:Proxy_Password@Proxy_IP:Port

3. If you want to set the proxy access to a specific user then you need to set the variable on their bash profile.

# vi /home/vibhor/.bash_profile

Append the following line:

export http_proxy=http://Proxy_User:Proxy_Password@Proxy_IP:Port

or 

export http_proxy=http://Proxy_IP:Proxyport

You can use the https proxy or ftp proxy also only required to change the name of the varibale. 

HP-UX Logical Volume Manager (LVM) Commands with an Example

In this post, You can get an idea about HP-UX logical volume manager commands with an example. As you know LVM is basically used for disk management in operating system that allow to manager the physical disks and logical volume.

Please find the below HP-UX LVM commands with an example.

1. Create a new volume group, logical volume and file system:

You can used the below command in HP-UX operating system to create a new volume group, logical volume and file system.

hpx:/>pvcreate /dev/rdsk/c2t1d0

For creating a new volume group first we need to create physical volume as describe in above command.

hpx:/>mkdir /dev/vg01

hpx:/>mknod /dev/vg01/group c 64 0x010000

In above step we will create a directory where we need to create a volume group.

hpx:/>vgcreate /dev/vg01 /dev/dsk/c2t1d0

After successfully creation of volume group we will create a new logical voulme as describe in below command.

hpx:/>lvcreate -L 2048 /dev/vg01

hpx:/>newfs -F vxfs -o largefiles /dev/vg01/vgvol1

Using above command we create a new file system now in next step we will create a directory where we need to mount the newly created file system.

hpx:/>mkdir /backup

hpx:/>mount /dev/vg01/vgvol1 /backup

Once you mount the logical voulme with file system you can run the file system checking command to verify that mounting is succesfully or not.

2. Create a stripped filesystem:

In this, we will create a stripped file system with the help of volume group and logical voulme.

hpx:/>lvcreate -i 2 -I 32 -L 48 -n vgvol1 /dev/vg01

-i number of stripes

-I stripe size of 32KB

-L size of the volume

3. HP-UX display boot information:

You can use the below command to display boot information.

hpx:/>lvlnboot -v /dev/vg00

Boot Definitions for Volume Group /dev/vg00:

Physical Volumes belonging in Root Volume Group:

        /dev/dsk/c2t0d0 (0/1/1/0.0.0) -- Boot Disk

        /dev/dsk/c2t1d0 (0/1/1/0.1.0) -- Boot Disk

Boot: lvol1     on:     /dev/dsk/c2t0d0

                        /dev/dsk/c2t1d0

Root: lvol3     on:     /dev/dsk/c2t0d0

                        /dev/dsk/c2t1d0

Swap: lvol2     on:     /dev/dsk/c2t0d0

                        /dev/dsk/c2t1d0

Dump: lvol2     on:     /dev/dsk/c2t0d0, 0

When you run the above command you can find the above output , if you see the boot information you can find you have two disk which is available for boot.

4. HP-UX display all disks system information:

hpx:/> ioscan -funC disk

Class     I  H/W Path        Driver   S/W State   H/W Type     Description

==============================================================

disk      0  0/0/2/0.0.0.0   sdisk    CLAIMED     DEVICE       TEAC    DV-28E-N

                            /dev/dsk/c0t0d0   /dev/rdsk/c0t0d0

disk      1  0/1/1/0.0.0     sdisk    CLAIMED     DEVICE       HP 146 GMAX3147NC

                            /dev/dsk/c2t0d0   /dev/rdsk/c2t0d0

disk      2  0/1/1/0.1.0     sdisk    CLAIMED     DEVICE       HP 146 GMAX3147NC

                            /dev/dsk/c2t1d0   /dev/rdsk/c2t1d0

In the above output you can found the all the disk which is available in the system.

5. HP-UX display dump devices:

hpx:/> lvlnboot -v

Normally it is showing the boot information in which you can check the dump devices name.