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  • Sachin Thapa 22:31 on February 21, 2015 Permalink | Reply
    Tags: , ,   

    AIX Logical Volume Manager (LVM) 

    This is a quick and dirty cheat sheet on LVM using AIX, I have highlighted many of the common attributes for each command however this is not an extensive list, make sure you look up the command.

    First a quick review on some of the terminology that AIX LVM uses (More …)

  • Sachin Thapa 22:29 on February 21, 2015 Permalink | Reply
    Tags: hpux, ,   

    HPUX Boot Process 

    The boot process on a HP server is reduce to three steps

    PDC HPUX system come with firmware installed called Processor Dependent Code (PDC) The PDC run self-test operations and initialises the processor. The interface to the PDC commands is called the Boot Console Handler (BCH)
    ISL The Initial System Loader is run after the PDC, there are a number of commands that can be run from the ISL
    hpux utility that manages loading the HP-UX kernel and gives control to the kernel. Commands can be gven to the kernel. Sometimes this is called the Secondary System Loader (SSL)

    PDC (More …)

  • Sachin Thapa 22:28 on February 21, 2015 Permalink | Reply
    Tags: , hp/aix, ,   

    HP Logical Volume Manager (LVM) 

    Logical Volume Manager is a disk management subsystem that allows you to manage physical disks as logical volumes.

    The following terms are used when working with LVM:

    Volume A volume is a device used for a filesystem, swap or raw data. Without LVM a volume would be a disk partition or the whole disk
    Physical Volume A physical volume is the disk itself. An entire disk must be initialised if it is to be used by LVM.
    Volume Group A volume Group is a collection of volumes that are managaed by LVM. Each disk must only belong to one group however a volume group many contain many disks.
    Logical Volume This is the space that is defined within a volume group. The volume group is divided into smaller logical volumes which in turn become the filesystems. A volume group may contain one or many logical volumes. Logical volumes can be grown or shrunk. A logical volume is a set of logical extents
    Physical Extent A physical extent is a set of contiguous disk blocks on a physical volume. The default size of an extent is 4MB but this can be adjusted when initialising the disk. Normally a physical extent will have a one to one relationship with logical extents.
    Logical Extent A logical volume is a set of logical extents. Logical extents and pyhsical extents are the same size in a volume. A logical extent is a direct mapping to a pyhsical extent.
    /etc/lvmtab This file has in it the device file associated with each disk in a volume group. /sbin/lvmrc starts each volume group by reading the contents of this file at boot time.This file can be rebuilt using the command vgscan. The file is a binary file and can be read using Strings.
    PV Links Physical Volume Links (PV Links) provide dual SCSI or FL links to the same disk. This basically means multipathing to a disk.

    (More …)

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