> What does Logical Volume Manager(LVM) mean ?
The set of operating system commands, library subroutines and other tools that allow you to establish and control logical volume storage is called the Logical Volume Manager (LVM).
> What is a Logical partition ?
A logical partition (LPAR) is the division of a computer's processors, memory, and hardware resources into multiple environments so that each environment can be operated independently with its own operating system and applications.
> Explain Network File Systems(NFS) ?
The Network File System (NFS) is a distributed file system that allows users to access files and directories of remote servers as if they were local. Suppose, Server A, that makes its file systems, directories, and other resources available for remote access. Client's computers, or their processes, that use a server's resources. Export the act of making file systems available to remote clients. Mount the act of a client accessing the file systems that a server exports.
> What is Network Information Service (NIS) ?
NIS was developed to simplify the task of administrating a number of machines over a network. In particular was the requirement to maintain copies of common files (e.g. password, group and host) across different systems.
> What is daemon ?
A daemon (pronounced DEE-muhn) is a program that runs continuously and exists for the purpose of handling periodic service requests that a computer system expects to receive. The daemon program forwards the requests to other programs (or processes) as appropriate. Each server of pages on the Web has an HTTPD or Hypertext Transfer Protocol daemon that continually waits for requests to come in from Web clients and their users.
> What is Hardware Management Console (HMC) ?
The HMC is a server or stand alone machine that provides a graphical user interface tool to manage several Power Systems. The HMC manages system through hypervisor and operating system. From version 7 it is truly web based and you can configure, installs and manage, partitioned, virtualization most of your Power5 and 6 boxes via HMC. There are many tasks you can do with HMC, such as,
• Powering off and on of the partition
• Configure and activate resources to the system
• Creates and stores LPAR profiles and allocated resources to them.
• HMC do the dynamic memory reconfiguration of the partition.
• Setup VIO server and VIO client thru HMC and do micro-partition, create storage
• pool and processor pool with it
• Provide virtual console to the partition
Most of the time we installed dual HMC for redundancy and make sure to achieve more uptime in a wide system.
> Why do I need a Hardware Management Console, anyway ?
You need a HMC if you plan to:
- Configure and manage logical partitions and partition profiles (selected models can configure LINUX partitions without a HMC).
- Perform DLPAR (dynamic LPAR) functions.
- Activate and manage Capacity on Demand resources.
You can also use the HMC to:
- Perform service functions
- Manage frames (towers), IOPs and IOAs. * Note that you cannot see below the IOA to the device level.
- Manage system profiles (yes, you can have more than one!)
- Power on and power down. The Service Processor is always hot if there is power to the server.
- Activate and manage Virtualization Engine technologies.
- 5250 emulation so you can get a console up on a i5/OS partition or a virtual terminal window for AIX or LINUX.
> Does HACMP work on different operating systems ?
Yes. HACMP is tightly integrated with the AIX 5L operating system and System p servers allowing for a rich set of features which are not available with any other combination of operating system and hardware. HACMP V5 introduces support for the Linux operating system on POWER servers. HACMP for Linux supports a subset of the features available on AIX 5L, however this mutli-platform support provides a common availability infrastructure for your entire enterprise.
> What applications work with HACMP ?
All popular applications work with HACMP including DB2, Oracle, SAP, WebSphere, etc. HACMP provides Smart Assist agents to let you quickly and easily configure HACMP with specific applications. HACMP includes flexible configuration parameters that let you easily set it up for just about any application there is.
> How do I know if my volume group is normal, big, or scalable ?
Run the lsvg command on the volume group and look at the value for MAX PVs. The value is 32 for normal, 128 for big and 1,024 for scalable volume group.
> How do I create a volume group ?
Use the following command, where s partition_size sets the number of megabytes (MB) in each physical partition where the partition_size is expressed in units of MB from one through 1,024. (It's one through 131,072 for AIX 5.3.)
The partition_size variable must be equal to a power of two (for example: one, two, four or eight). The default value for standard and big volume groups is the lowest value to remain within the limitation of 1,016 physical partitions per physical volume. The default value for scalable volume groups is the lowest value to accommodate 2,040 physical partitions per physical volume.
> How can I change the characteristics of a volume group ?
You use the chvg command to change the characteristics of a volume group.
> How do I create a logical volume ?
#mklv -y name_of_logical_volume name_of_volume_group number_of_partition
> How do I increase the size of a logical volume ?
To increase the size of the logical volume represented by the lv05 directory by three logical partitions, for example, type extendlv lv05 3.
> How do I display all logical volumes that are part of a volume group (e,g, rootvg) ?
You can display all logical volumes that are part of rootvg by typing the following command: #lsvg -l rootvg/
> How do I list information about logical volumes ?
Run the following command to display information about the logical volume #lv1: lslv lv1.
> How can I clone the rootvg ?
You can run the alt_disk_copy command to copy the current rootvg to an alternate disk. The following example shows how to clone the rootvg to hdisk1: alt_disk_copy -d hdisk1.]
> How do I replace a disk ?
extendvg VolumeGroupName hdisk_new
migratepv hdisk_bad hdisk_new
reducevg -d VolumeGroupName hdisk_bad
> How do I mirror a logical volume ?
mklvcopy LogicalVolumeName Numberofcopies
> How can I display or set values for network parameters ?
The no command sets or displays current or next boot values for network tuning parameters
> How do I get the IP address of my machine ?
Type one of the following: ifconfig -a or host Fully_Qualified_Host_Name. For example, host cyclop.austin.ibm.com.