Two Node Cluster Storage

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This is a collection of ASCII images showing storage in clusters.

Two Node

These are storage maps used in two-node clusters.

Clustered LVM On DRBD Backed By Direct Drive Storage

           an-node01
  ______   ______    ______     __[sda4]__
 | sda1 | | sda2 |  | sda3 |   |  ______  |       _______    ______________    ______________________________
 |______| |______|  |______|   | | sda5 |-+------| drbd0 |--| drbd_sh0_vg0 |--| /dev/drbd_sh0_vg0/xen_shared |
     |        |         |      | |______| |   /--|_______|  |______________|  |______________________________|
  ___|___    _|_    ____|____  |  ______  |   |     _______    ______________    ____________________________
 | /boot |  | / |  | <swap>  | | | sda6 |-+---+----| drbd1 |--| drbd_an1_vg0 |--| /dev/drbd_an1_vg0/vm0001_1 |
 |_______|  |___|  |_________| | |______| |   | /--|_______|  |______________|  |____________________________|
                               |  ______  |   | |     _______    ______________    ____________________________
                               | | sda7 |-+---+-+----| drbd2 |--| drbd_an2_vg0 |--| /dev/drbd_an1_vg0/vm0002_1 | 
                               | |______| |   | | /--|_______|  |______________|  |____________________________|
                               |  ______  |   | | |                         | |    _______________________
                               | | sda8 |-+---+-+-+--\                      | \---| Example LV for 2nd VM |
                               | |______| |   | | |  |                      |     |_______________________|
                               |__________|   | | |  |                      |      _______________________
           an-node02                          | | |  |                      \-----| Example LV for 3rd VM |
  ______   ______    ______     __[sda4]__    | | |  |                            |_______________________|
 | sda1 | | sda2 |  | sda3 |   |  ______  |   | | |  |                   
 |______| |______|  |______|   | | sda5 |-+---/ | |  |   _______    __________________
     |        |         |      | |______| |     | |  \--| drbd3 |--| Spare PV for     |
  ___|___    _|_    ____|____  |  ______  |     | |  /--|_______|  | future expansion |
 | /boot |  | / |  | <swap>  | | | sda6 |-+-----/ |  |             |__________________|
 |_______|  |___|  |_________| | |______| |       |  |
                               |  ______  |       |  |
                               | | sda7 |-+-------/  |
                               | |______| |          |
                               |  ______  |          |
                               | | sda8 |-+----------/
                               | |______| |
                               |__________|

Clustered LVM On DRBD Backed By RAID Level 1 Storage

Below is an ASCII drawing which should help you see how DRBD will tie in to the rest of the cluster's storage. This map assumes a simple RAID level 1 array underlying each node. If your node has a single hard drive, simply collapse the first two layers into one. Similarly, if your underlying storage is a more complex RAID array, simply expand the number of physical devices at the top level.

               Node1                                Node2
           _____   _____                        _____   _____
          | sda | | sdb |                      | sda | | sdb |
          |_____| |_____|                      |_____| |_____|
             |_______|                            |_______|
     _______ ____|___ _______             _______ ____|___ _______
  __|__   __|__    __|__   __|__       __|__   __|__    __|__   __|__
 | md0 | | md1 |  | md2 | | md3 |     | md3 | | md2 |  | md1 | | md0 |
 |_____| |_____|  |_____| |_____|     |_____| |_____|  |_____| |_____|
    |       |        |       |           |       |        |       |
 ___|___   _|_   ____|____   |___________|   ____|____   _|_   ___|___
| /boot | | / | | <swap>  |        |        | <swap>  | | / | | /boot |
|_______| |___| |_________|  ______|______  |_________| |___| |_______|
                            | /dev/drbd0  |
                            |_____________|
                                   |
                               ____|______
                              | clvm PV   |
                              |___________|
                                   |
                              _____|_____
                             | drbd0_vg0 |
                             |___________|
                                   |
                              _____|_____ ___...____
                             |           |          |
                          ___|___     ___|___    ___|___
                         | lv_X  |   | lv_Y  |  | lv_N  |
                         |_______|   |_______|  |_______|

 

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