WWID in HPUX

This blog shows how to get the WWID (UUID) of the LUN's allocated using the HP Storage.

# scsimgr -v get_info -H <Hardware Path> : Command to get the WWID of the LUNS allocated through that hardware path.

# fcmsutil /dev/fc# get remote all : Command to check the commuincation between the server HBA to all the remote (switch ports) and storage HBA.

HBA statistics in HP Unix

The below posts show, how to handle and trouble shoot a FC HBA in Hp unix:


# ioscan -funC fc : Command shows all the FC HBA on the box.

# fcmsutil <device_file_name> : Command show the n_port WWN and Switch port WWN.

# fcmsutil <device_file_name> stat -s : Command shows IO stats on the HBA.

# fcmsutil <device_file_name> get remote all : Command check the HBA remote connection.

# fcmsutil <device_file_name> disable : Command to disable the HBA.

# fcmsutil <device_file_name> enable : Command to enable the HBA.

Hot Swappable Disk Replacement in AIX

This posts concentrated on Disk Replacement in AIX:

We conclude the disk has failed after looking at the disk state with the "errpt" diagnosis and the PVstate as "missing"

# errpt -N hdisk#

# lspv pvname

If the disk is a part of a  mirrored volume group, follow the below steps:

1) # unmirrorvg vgname <failed_pv> : Command to unmirror  the volume group from failed physical volume.

2) # reducevg -d- f vgname <failed_pv> : Command to remove the failed disk from the volume group.

3) # lscfg -vpl <failed_pv>: Make a note of the Physical Location of the failed Physical volume.

4) # rmdev  -dl <failed_pv> : Remove the failed disk from the ODM.

5) #diag  --> Task Manager --> Hot Plug Task--> Select SCSI and SCSI RAID Hot Plug Manager -->Select Replace/Remove a Disk attached to SCSI Hot Swap Enclosure-->Select the Device to be replaced and Press Enter.

Veritas Volume Manager Commands

# vxdisk list :Commad to list all the disk recognized by the VxVM.

# vxdisksetup -i <disk_name> :Command to initialize a physical volume under VxVM format.

# vxdiskunsetup <disk_name> :Command to remove a physical volume under VxVM format.

# vxdg init <disk_group_name> cds=on <disk_name>=<Physical_volume> : Command to create a disk group with the disk.

# vxprint -htg <disk_group>: Command to view the disk group created.

# vxinfo -g <disk_group_name> : Command shows the volume created in the disk group.

# vxinfo -g <disk_group_name> -p : Shows the plexes in the disk group.

Identifying the boot disk in AIX and HPUX

# bootinfo -b :Command to identify the present boot disk in IBM AIX.

# bootinfo -d :Command to identify the last boot disk  in IBM AIX.

# setboot -v : Command displays the Hardware path the of the primary and alternate boot disk in HPUX.

# ioscan -funH <Hardware_path> -C disk : Command to get the disk on the path in HPUX..

# lvlnboot -v : Command get the boot disk in HPUX..

Virtual Home Directory

In UNIX, a user can login only when they have an account in the server which has an entry at /etc/passwd and other files.

The default location where the user logs in is their respective home directory /home/<username> execpt the "
root". "Root" user logs into "/".

The home directory is created when the # useradd command is used with "-m" flag.

#useradd -m test : Command creates a user called "test" with the home directory of the same name under "/home".

#useradd test : Command create the user "test" with the default attributes.

So what makes the difference when this is executed:

#su - test
#echo $HOME

On the both the case the output will be "/home/test". But the difference is,

# useradd -m test : Creates a home directory.

#useradd test : Created a virtual directory, that is the directory does not exist in real, but allow the users to login by "#su - test", and the user do not have any control like creating a file / reading a file when they login into the virtual directory.

AIX LVM Header file

When we execute LVM Command, we get a numerical value as a result of the execution of the command.

Each value has a meaning in it which describes the nature of the LVM command executed and the outcome.


bash-3.2# exportvg vg01
0516-764 exportvg: The volume group must be varied off before exporting.

Here I am trying to export a volume group, which is an active one and it generates a numerical value as well.

/usr/include/lvm.h : This is the file that contains all the variable declaration for the LVM structures.

Booting Phases of HPUX

The booting process of HP Unix is classified into 5 steps:

1) PDC : Processor Dependent Code.

2) ICL : Initial Controller Load.

3) Loading the kernel.

4) Startup scripts.

5) Console login.

Useful HPUX Administrator Commands

# ioscan -funC : Scans for disk attached to the machine.

# ioscan -funC fc : Scans for FC adapter on the machine.

# ioscan -P health -C disk : Shows health status of all the disk.

# ioscan -funC tape : Scans for tape drive on the machine.

# ioscan -m dsf : Mapping between Persistent DSF and Legacy DSF.

# ioscan -funH <Hardware_Path> : Shows list of devices connected to the hardware path.

# ioscan -m lun : Command show the LUN on the machine.

# ioscan -m lun -h <Hardware_Path> : Mapping between the LUN and the Hardware path.

# ioscan -fn : Shows all the devices on the machine.

# lanscan -aip : Show the all the interfaces MAC and Instance Number.

# lanadmin -g <Instance_Number> : Complete information for a particular Interface.

# linkloop -i <Instance_Number> <MAC> : Check the physical cable connectivity of the interface.

# nwmgr : Starting HPUX 11.30, shows physical connectivity of all the interfaces.

# ioscan -fn | grep -i "no_hw" : Get the devices that are not claimed or not in use.

# strings /etc/lvmtab : Command to get the volume groups created and the physical volumes in it.

# lvlnboot -v : Shows current boot logical volume, swap, dump and root logical volume.

# swapinfo -atm : Information about swap space.

# top : Complete information about the machine.

# glance : Complete information about the machine. Similar to "topas" in AIX.

# vmstat -d 1 5 : Shows virtual memory information with "Disk Performance".

Configuration of Dump Device in Hp Unix

This blog states how to configure Dump device and activate a dump device in HP Unix.

Dump Device refer to an object which plays a vital role during the system crash. On the occurence of a system crash the machine reboots, an image of the system (including hardware and software) will be taken as a dump image and stored in a file system. This information can be used for debugging purpose to analyze the reason for crash.

Steps for configuration:

In HP Unix, by default the paging space is also used as a dump device. "lvol2".

1) The dump device should be a size larger than the size of the RAM.

# dmesg | grep -i physical : Command to get the RAM Size.

2) Create a logical volume of continous allocation and bad block allocation disabled.

# lvcreate -n dump -L 1024 -C y -r n  <Volum_Group_Name> : Command to create a logical volume.

3) Assign the created logical volume as a dump device.

# lvlnboot -d /dev/vg_name/lv_name

4) Verify the dump has been assigned.

# lvlnboot -v

Reboot the machine for the dump to get effective.

Swap Device in HP_Unix

This post mainly deals with the management of swap space in hp unix.

Swap refers to the Virtual space or Paging space as referred according to the UNIX flavour.

Importance of Swap Space has the ability to provide much memory space than the machine has.

The default swap space in hp unix  "/dev/vg#/lvol2".

Logical volume of partition "2" is assigned as default swap space. This space cannot be extended or reduced.

# lvcreate -n <Logical_Volume_Name> -L <Size_of_LV> <Volume_Group_Name> : Command to create a logical volume of desired size.

Swap Space should be twice the size of Physical Memory.

# swapon <Logical_Volume_Name> : Command to assign the the created the logical volume as a swap device.

# swapinfo -dtm : Command to verify the created swap device is created an activated.

Ensure the entry has been  made at "/etc/fstab" for the swap space to persist across the reboot.

/etc/fstab

<Logical_Volume_Name>   "/"   swap   defaults 0 0