help understand disk managment - Redhat

This is a discussion on help understand disk managment - Redhat ; Could someone point me to a web site with good illustration/explanation on linux disk concepts including physical volume, logical volume, volume group, types of linux partition, extends, ... I have already visited several linux sites but still don't quite understand ...

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  1. help understand disk managment

    Could someone point me to a web site with good illustration/explanation on
    linux disk concepts including
    physical volume, logical volume, volume group, types of linux partition,
    extends, ...

    I have already visited several linux sites but still don't quite understand
    the whole picture. Different sites seem to explain the concepts in a totally
    different way.

    I came from windows background. If someone could explain the stuff using
    windows terminology, or contrast compare with windows, perhaps it would
    help.



  2. Re: help understand disk managment

    peter wrote:

    > Could someone point me to a web site with good
    > illustration/explanation on linux disk concepts including
    > physical volume, logical volume, volume group, types of linux
    > partition, extends, ...
    >
    > I have already visited several linux sites but still don't quite
    > understand the whole picture. Different sites seem to explain the
    > concepts in a totally different way.
    >
    > I came from windows background. If someone could explain the stuff
    > using windows terminology, or contrast compare with windows, perhaps
    > it would help.



    http://www.redhat.com/docs/manuals/l...artitions.html
    http://www.linuxplanet.com/linuxplan...orials/4269/1/


    --
    Contained within the Microsoft EULA;
    This Limited Warranty is void if failure of the Product has resulted
    from accident, abuse, misapplication, abnormal use or a virus.

  3. Re: help understand disk managment

    Thanks, now I know why I was confused. There are two types of file systems
    in redhat.

    In the simple type, hard drives are partitioned and partitions are mounted.

    In the complicated type (LVM), drives are divided into physical volume, then
    physical volumes are combineded into a logical volume group, which is like a
    big resizable virtual drive. This logical volume group can then be
    "partitioned" into logical volumes which can then be mounted and resized at
    will.

    Is this more or less correct? What is the correct way to refer to the simple
    type file system?

    "Lenard" wrote in message
    news:YS9Oe.469$L77.163@newssvr19.news.prodigy.com. ..
    >
    >
    > http://www.redhat.com/docs/manuals/l...artitions.html
    > http://www.linuxplanet.com/linuxplan...orials/4269/1/




  4. Re: help understand disk managment

    "peter" writes:
    > Thanks, now I know why I was confused. There are two types of file
    > systems in redhat.
    >
    > In the simple type, hard drives are partitioned and partitions are
    > mounted.
    >
    > In the complicated type (LVM), drives are divided into physical
    > volume, then physical volumes are combineded into a logical volume
    > group, which is like a big resizable virtual drive. This logical
    > volume group can then be "partitioned" into logical volumes which
    > can then be mounted and resized at will.
    >
    > Is this more or less correct? What is the correct way to refer to
    > the simple type file system?


    disk partitioning, ala ms/dos
    ... sort of like minidisks from cp/67 ... circa mid-60s

    minor ref
    http://www.garlic.com/~lynn/2004e.html#38 [REALLY OT!] Overuse of symbolic constants
    http://www.garlic.com/~lynn/2004h.html#40 Which Monitor Would You Pick??????
    http://www.garlic.com/~lynn/2004k.html#46 Xah Lee's Unixism

    LVM started with aix/v3 for rs/6000
    included support for things other than straight partitioning,
    striping, mirroring, concatenation, etc

    as an aside ... journaled file system (JFS) was also done for
    for the same rs/6000 aix/v3 release

    .....

    .... so one flavor is sort of the ms/dos heritage ... modulo minidisks
    and virtual machine stuff from the mid-60.

    the other flavor is somewhat more unix heritage ... at least from
    aix/v3.

    --
    Anne & Lynn Wheeler | http://www.garlic.com/~lynn/

  5. Re: help understand disk managment

    peter wrote:

    > Thanks, now I know why I was confused. There are two types of file
    > systems in redhat.
    >
    > In the simple type, hard drives are partitioned and partitions are
    > mounted.
    >
    > In the complicated type (LVM), drives are divided into physical
    > volume, then physical volumes are combineded into a logical volume
    > group, which is like a big resizable virtual drive. This logical
    > volume group can then be "partitioned" into logical volumes which can
    > then be mounted and resized at will.
    >
    > Is this more or less correct? What is the correct way to refer to the
    > simple type file system?


    First learn how to not top post please.

    Second in answer to your questions and comments;
    Partitions are partitions and volumes are volumes. You cannot have a
    volume without first having one or more partitions. Volumes should not
    be considered as big re-sizable virtual drive but as a 'container' for
    the partitions.

    This should help;

    http://linux-ntfs.sourceforge.net/ld...w/volumes.html


    --
    Contained within the Microsoft EULA;
    This Limited Warranty is void if failure of the Product has resulted
    from accident, abuse, misapplication, abnormal use or a virus.

  6. Re: help understand disk managment

    "peter" wrote in message
    news:h%lOe.6391$137.1131@trnddc08...
    > Thanks, now I know why I was confused. There are two types of file systems
    > in redhat.


    Another reason I was confused is caused by the name "logical volume group".
    The name implies it is a group of logical volumes when in fact it is a group
    of physical volumes. I suggest we rename it "physical volume group".



  7. Re: help understand disk managment

    "peter" writes:
    > Another reason I was confused is caused by the name "logical volume
    > group". The name implies it is a group of logical volumes when in
    > fact it is a group of physical volumes. I suggest we rename it
    > "physical volume group".


    one of the reason for the original LVM label ... were options other
    than 1:1 mapping between the logical volume and the physical
    partition(s) ... aka mirroing, stripping, concatenation.

    the ms/pc dos stuff purely did physical partitioning with a 1:1
    mapping between the (virtual) disk (for filesystem) and the physical
    partition.

    when we did ha/cmp product
    http://www.garlic.com/~lynn/subtopic.html#hacmp

    .... another minor reference
    http://www.garlic.com/~lynn/95.html#13

    we used lvm mirroring for no-single-point-of-failure ... and JFS for
    fast restart after outage.

    there were even gimicks played with 3-way mirroring for backup ...
    add a (LVM) 3rd mirror on the fly ... wait until it sync'ed ... and
    then took one of the mirrored disks offline and sent offsite for
    disaster/recovery.

    --
    Anne & Lynn Wheeler | http://www.garlic.com/~lynn/

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