test/librados/cmd.cc: tolerate thrashing on pg_command tests

We may get ENXIO (osd down) or ENOENT (pg dne (yet) on the target osd) if
there is thrashing going on.

Fixes: #6122
Signed-off-by: Sage Weil <sage@inktank.com>
doc: Added draft of configuration guide for federated gateways.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added entry for federated configuration to the index.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
ceph-disk: make initial journal files 0 bytes

The ceph-osd will resize journal files up and properly fallocate() them
so that the blocks are preallocated and (hopefully) contiguous.  We
don't need to do it here too, and getting fallocate() to work from
python is a pain in the butt.

Fixes: #5981
Signed-off-by: Sage Weil <sage@inktank.com>
doc: Added conf example.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Excised content from "Getting Started" and created Intro to Ceph.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added Intro to Ceph to Index.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Updated for 3-node deployment and multiple Linux distributions.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Removed introductory material. Renamed the page.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Updated for 3-node deployment. Leaner discussion. More use cases.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Made sysvinit and service sections parallel to upstart for clarity.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Updated link to Storage Cluster Quick Start.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Updated link to Storage Cluster Quick Start.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Updated link to Storage Cluster Quick Start.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Added draft of region/zone diagram.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
doc: Made some changes and incorporated a draft diagram.

Signed-off-by: John Wilkins <john.wilkins@inktank.com>
osd: move pow2_hist_t out of osd_types and into include/

This has only been used for the OSD so far, but as with the rest
of the OpRequest stuff, it's actually pretty generic.

Signed-off-by: Greg Farnum <greg@inktank.com>
OpRequest: remove obsolete comment about ref-counting (use OpRequestRef!)

Signed-off-by: Greg Farnum <greg@inktank.com>
OpTracker: start making the OpTracker into a generic

We're starting by templating the create_request function and having
the OpTracker work in terms of TrackedOp[Ref]s intead of
OpRequest[Ref]s. This involves moving a bunch of stuff into the
base-class TrackedOp.

Signed-off-by: Greg Farnum <greg@inktank.com>
OpTracker: add an init_from_message() to the TrackedOp interface

This can be used for the concrete implementations to gather any
extra data out of the message and do whatever extra setup based
on that they want. The OpTracker will call this after doing all its
internal setup but before anybody else gets to see the TrackedOp.

Signed-off-by: Greg Farnum <greg@inktank.com>