Commit ce0484b7 authored by Constantinos Venetsanopoulos's avatar Constantinos Venetsanopoulos
Browse files

docs: Remove Archipelago section from Admin guide

Archipelago has its own, new, separate documentation:
http://www.synnefo.org/docs/archipelago/latest/
which is independent from Synnefo. Thus, remove the old
Archipelago section from the Admin guide.
parent 1ce6a435
......@@ -494,7 +494,6 @@ Finally, backend systems having acquired a token can use the
:ref:`authenticate-api-label` API call from a private network or through HTTPS.
Compute/Network/Image Service (Cyclades)
========================================
......@@ -858,219 +857,6 @@ these messages and properly updates the state of the Cyclades DB. Subsequent
requests to the Cyclades API, will retrieve the updated state from the DB.
Block Storage Service (Archipelago)
===================================
Overview
--------
Archipelago offers Copy-On-Write snapshotable volumes. Pithos images can be used
to provision a volume with Copy-On-Write semantics (i.e. a clone). Snapshots
offer a unique deduplicated image of a volume, that reflects the volume state
during snapshot creation and are indistinguishable from a Pithos image.
Archipelago is used by Cyclades and Ganeti for fast provisioning of VMs based on
CoW volumes. Moreover, it enables live migration of thinly-provisioned VMs with
no physically shared storage.
Archipelago Architecture
------------------------
.. image:: images/archipelago-architecture.png
:width: 50%
:target: _images/archipelago-architecture.png
.. _syn+archip+rados:
Overview of Synnefo + Archipelago + RADOS
-----------------------------------------
.. image:: images/synnefo-arch3.png
:width: 100%
:target: _images/synnefo-arch3.png
Prereqs
-------
The administrator must initialize the storage backend where archipelago volume
blocks will reside.
In case of a files backend, the administrator must create two directories. One
for the archipelago data blocks and one for the archipelago map blocks. These
should probably be over shared storage to enable sharing archipelago volumes
between multiple nodes. He or she, must also be able to supply a directory where
the pithos data and map blocks reside.
In case of a RADOS backend, the administrator must create two rados pools, one
for data blocks, and one for the map blocks. These pools, must be the same pools
used in pithos, in order to enable volume creation based on pithos images.
Installation
------------
Archipelago consists of
* ``libxseg0``: libxseg used to communicate over shared memory segments
* ``python-xseg``: python bindings for libxseg
* ``archipelago-kernel-dkms``: contains archipelago kernel modules to provide
block devices to be used as vm disks
* ``python-archipelago``: archipelago python module. Includes archipelago and
vlmc functionality.
* ``archipelago``: user space tools and peers for the archipelago management and
volume composition
* ``archipelago-ganeti``: ganeti ext storage scripts, that enable ganeti to
provision VMs over archipelago
Performing
.. code-block:: console
$ apt-get install archipelago-ganeti
should fetch all the required packages and get you up 'n going with archipelago
Bare in mind, that custom librados is required, which is provided in the apt
repo of GRNet.
For now, librados is a dependency of archipelago, even if you do not intend to
use archipelago over RADOS.
Configuration
-------------
Archipelago should work out of the box with a RADOS backend, but basic
configuration can be done in ``/etc/default/archipelago`` .
If you wish to change the storage backend to files, set
.. code-block:: console
STORAGE="files"
and provide the appropriate settings for files storage backend in the conf file.
These are:
* ``FILED_IMAGES``: directory for archipelago data blocks.
* ``FILED_MAPS``: directory for archipelago map blocks.
* ``PITHOS``: directory of pithos data blocks.
* ``PITHOSMAPS``: directory of pithos map blocks.
The settings for RADOS storage backend are:
* ``RADOS_POOL_MAPS``: The pool where archipelago and pithos map blocks reside.
* ``RADOS_POOL_BLOCKS``: The pool where archipelago and pithos data blocks
reside.
Examples can be found in the conf file.
Be aware that archipelago infrastructure doesn't provide default values for this
settings. If they are not set in the conf file, archipelago will not be able to
function.
Archipelago also provides ``VERBOSITY`` config options to control the output
generated by the userspace peers.
The available options are:
* ``VERBOSITY_BLOCKERB``
* ``VERBOSITY_BLOCKERM``
* ``VERBOSITY_MAPPER``
* ``VERBOSITY_VLMC``
and the available values are:
* 0 : Error only logging.
* 1 : Warning logging.
* 2 : Info logging.
* 3 : Debug logging. WARNING: This options produces tons of output, but the
logrotate daemon should take care of it.
Working with Archipelago
------------------------
``archipelago`` provides basic functionality for archipelago.
Usage:
.. code-block:: console
$ archipelago [-u] command
Currently it supports the following commands:
* ``start [peer]``
Starts archipelago or the specified peer.
* ``stop [peer]``
Stops archipelago or the specified peer.
* ``restart [peer]``
Restarts archipelago or the specified peer.
* ``status``
Show the status of archipelago.
Available peers: ``blockerm``, ``blockerb``, ``mapperd``, ``vlmcd``.
``start``, ``stop``, ``restart`` can be combined with the ``-u / --user`` option
to affect only the userspace peers supporting archipelago.
Archipelago advanced operations
-------------------------------
The ``vlmc`` tool provides a way to interact with archipelago volumes
* ``vlmc map <volumename>``: maps the volume to a xsegbd device.
* ``vlmc unmap </dev/xsegbd[1-..]>``: unmaps the specified device from the
system.
* ``vlmc create <volumename> --snap <snapname> --size <size>``: creates a new
volume named <volumename> from snapshot name <snapname> with size <size>.
The ``--snap`` and ``--size`` are optional, but at least one of them is
mandatory. e.g:
``vlmc create <volumename> --snap <snapname>`` creates a volume named
volumename from snapshot snapname. The size of the volume is the same as
the size of the snapshot.
``vlmc create <volumename> --size <size>`` creates an empty volume of size
<size> named <volumename>.
* ``vlmc remove <volumename>``: removes the volume and all the related
archipelago blocks from storage.
* ``vlmc list``: provides a list of archipelago volumes. Currently only works
with RADOS storage backend.
* ``vlmc info <volumename>``: shows volume information. Currently returns only
volume size.
* ``vlmc open <volumename>``: opens an archipelago volume. That is, taking all
the necessary locks and also make the rest of the infrastructure aware of the
operation.
This operation succeeds if the volume is alread opened.
* ``vlmc close <volumename>``: closes an archipelago volume. That is, performing
all the necessary functions in the insfrastrure to successfully release the
volume. Also releases all the acquired locks.
``vlmc close`` should be performed after a ``vlmc open`` operation.
* ``vlmc lock <volumename>``: locks a volume. This step allow the administrator
to lock an archipelago volume, independently from the rest of the
infrastrure.
* ``vlmc unlock [-f] <volumename>``: unlocks a volume. This allow the
administrator to unlock a volume, independently from the rest of the
infrastructure.
The unlock option can be performed only by the blocker that acquired the lock
in the first place. To unlock a volume from another blocker, ``-f`` option
must be used to break the lock.
Synnefo management commands ("snf-manage")
==========================================
......@@ -1223,6 +1009,7 @@ reconcile-commissions-cyclades Detect and resolve pending commissions to Quotaho
reconcile-resources-cyclades Reconcile resource usage of Astakos with Cyclades DB.
============================== ===========================
Astakos helper scripts
======================
......@@ -1243,6 +1030,7 @@ cyclades, and pithos) in astakos database. It internally uses the script:
which simulates the export of service and resource definitions of the
standard Synnefo components.
Pithos managing accounts
========================
......
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