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From YouTube: Ceph Month 2021: CephFS update
Description
Presented by: Patrick Donnelly
Full schedule: https://pad.ceph.com/p/ceph-month-june-2021
A
I've
also
included
in
the
slides,
which
will
be
distributed
later.
The
blog
post
I
wrote
up,
which
also
includes
a
lot
of
these
discussion
topics
somewhat
in
more
detail.
Perhaps
so,
the
the
project
has
been
following
five
themes:
you
revolving
around
the
features
we've
been
developing
for
the
last
few
releases
and
that
and
we'll
begin
with
usability.
A
A
We
have
this
fs
volume
interface
that
allows
you
to
create
a
file
system
quite
easily,
including
all
of
its
pools.
Following
the
best
recommendations
of
this
of
first
half
and
automatically
just
deploy
mdss
using
the
distributed
or
the
deployment
backend
for
ceph,
either
cephadm
or
rook,
and
bring
up
as
many
file
systems
as
you
need
and
then
also
remove
them
as
you
need
another
usability
feature.
We've
developed
in
that
same
vein
is
the
mds,
auto
scaler,
which
will
start
and
stop
mdss
based
off
of
the
needs
of
the
file
systems
you
have.
A
This
is
a
module,
that's
not
enabled
by
default.
You
have
to
turn
it
on,
but
once
on
it
should
create
mdss
using
the
deployment
tool,
either
adm
or
rook
in
response
to
changes
of
the
configurations
of
your
of
your
ffs
file
system.
For
example,
if
you
increase
max
mds,
the
module
will
automatically
deploy
another
mds
in
response
to
that
change.
A
This
is
communicated
to
the
mds
and
the
mds
is
able
to
communicate
with
the
sef
the
cef
manager,
to
provide
a
summary
of
statistics
for
all
the
clients
in
the
cluster
and
display
a
simple
and
curses
ui
for
the
administrator,
showing
the
various
client
sessions
in
the
cef
file
system
and
what
they're
doing
and
who
the
top
consumers
are
again.
This
is
a
tech
preview,
but
we
are
spending
time
to
improve
it
always
and
we
are
eager
for
any
feedback
that
the
community
has.
A
In
that
same
vein,
we've
also
been
working
on
cfs
shell.
To
my
knowledge,
we
haven't
had
too
much
feedback
from
the
community.
This
has
been
around
for
about
two
releases.
Now,
two
or
three
releases,
it's
a
simple
python
utility
that
mounts
ffs
and
allows
you
to
execute
some
commands
on
the
file
system
without
having
to
mount
it
using
fuse
or
the
kernel.
A
We
also
have
a
new
snap
schedule
manager
module
that
also
must
be
enabled
that
allows
you
to
schedule
snapshots
on
a
step
file
system
on
a
given
period
and
also
retain
snapshots
according
to
a
retention
schedule.
That's
set
up
that
can
allow
you
to,
for
example,
set
up
snapshots
to
be
taken
every
day
for
a
week
and
then
delete
any
snapshots
that
are
that
are
older
than
that
time
frame.
A
A
The
the
you
can
set
up
the
nfs
clusters
in
active,
active
configurations
or
set
of
and
and
in
in
the
near
future,
you'll,
be
able
to
even
set
up
aha
using
ceph8m
with
aj
proxy.
That's
a
work
that
sage,
while
is
doing
right
now,
or
you
can
also
use
rook
for
for
the
aha
component,
although
the
rook
crd
is
under
active
development
right
now,
so
not
quite
yet
the
nfs
clusters
that
are
deployed
you
can
have
them
automatically
deployed
using
the
step
orchestrator.
A
A
All
right.
I
think
we
might
have
a
question
you
have
sharing
that
with
yes,
we're
doing
an
fs
crypt
instead
of
talk
tomorrow
at
9
30
a.m.
Eastern
time,
if
you
want
to
learn
more
about
that,
the
coming
back
to
the
robustness,
we
have
feature
bit
support
for
turning
on
and
off
required
file
system
features.
A
So
a
more
robust
solution
is
to
selectively
enable
and
disable
the
features
that
you
want,
and
that
is
all
the
api
for
that
is
all
set
up
and
documented
this
ftox.
If
you
want
to
learn
more,
the
we've
also
stabilized
multiple
mds
file
system,
scrub
that
is
in
in
the
past
before
pacific.
You
would
have
to
bring
your
self
ffs
file
system
down
to
max
mds
equals
one
so
reduce
the
number
of
ranks
to
one
before
you
could
run
a
scrub.
A
A
If
of
a
applications,
writing
to
the
mount
tries
to
come
back,
but
the
applications
that
had
read
handles
on
files
will
continue
to
function
and
new
applications
running
on
the
mount
can
do
reads
or
writes,
set
fuse
has
a
similar
feature
or
behavior
with
the
client
reconnect,
scalable
one
configuration
and
then
I'll
see.
If
you
want
to
do
this,
you
need
you
should
disable
the
page
cache.
A
A
Moving
on
to
performance,
another
big
feature
that
we've
had
that
was
partially
available
in
octopus.
As
development
preview
was
ephemeral
pinning
this
is
now
stable
and
what
this
is
is
a
policy-based
sub-tree
pinning
pinning
subtrees
has
been
around
since
I
believe
luminous
allowing
you
to
assign
a
given
subdirectory
treat
to
a
particular
mds
rank
ephemeral
pinning
allows
you
to
set
a
policy
saying
that
you
want
a
how
you
want
a
directory
or
a
group
of
directories
to
be
pinned
but
you're
not
actually
assigning
the
pin,
pin
directory
to
a
particular
rank.
A
A
Next,
we've
also
spent
a
lot
of
time
improving
the
capability
in
cash
management
in
the
mds
for
larger
clusters.
There's
this
has
been
an
issue.
We've
been
dealing
with
for
quite
a
several
releases
now,
and
we
believe
that
the
the
current
status
ffs
is
much
better
now
and
a
lot
more
stable
than
it
used
to
be.
The
most
recent
changes
we've
made
are
improving.
The
cap
recall
defaults
for
larger
production
clusters,
and
that
is
in
response
to
some
feedback.
A
A
A
A
A
A
Moving
on
to
ecosystem,
we
also
have
spent
a
lot
of
time
improving
the
use
of
cfs
with
kubernetes
csi
environments,
where
syphifest
is
used
for
rwx
or
rox
volumes.
Pvc
pvs-
and
this
is
all
orchestrated
through
the
volumes
plugin
in
the
cef
manager,
which
provides
an
api
for
creating
and
deleting
tvs
through
the
what
we
call
this:
the
sub
volume
interface
for
pacific.
A
We
added
a
support.
We
stabilized
the
snapshots
interface
for
our
sub
volumes
and
stabilized
the
interface
within
csi,
and
we
have
been
adding
a
new
authorization.
Api
support
for
openstack
manila,
which
is
also
in
the
process
supporting
to
use
this
new
api
and
also
have
added
ephemeral,
pinning
support
for
volumes.
A
A
A
For
performance,
what
we
would
like
to
do
next
is
add:
support
for
asynchronous
rm,
dur
maker
and
potentially
also
link
and
rename.
This
will
get
us
to
a
point
where
our
scene
can
run
extremely
quickly.
Those
are
the
last
remaining
our
pcs
that
the
that
we
would
need
to
make
a
asynchronous
to
improve
that
kind
of
workload
tremendously.
A
We
also
have
asynchronous
metadata
operations,
support
and
lips
ffs.
It's
currently
under
development.
We
expect
that
should
be
merged
for
quincy,
there's,
also
some
opportunities
to
improve
the
performance
of
set
fuse.
There
have
been
some
recent
changes
to
lib
views
that
we
believe
we
could
integrate
into
our
staff
use
library
to
just
take
advantage
of
the
latest
kernel
modifications
that
help
us
achieve
better
performance
within
lips
ffs.
A
A
We
also
are
developing
the
fs
cache
support
within
the
kernel,
client,
jeff
jeff
layton's
been
working
on
this.
The
fs
cache
interface
is
currently
being
refactored
and
reworked
by
david
howells
and
the
theft
kernel
client
is
being
constantly
updated
to
to
his
latest
changes
and
we're
hopeful
that
we
can
get
something
like
that
complete
by
the
by
the
quincy
release.
A
That's
especially
true
within
the
new
volumes
plug-in,
which
needs
to
regularly
delete
sub-volumes,
and
it
would
be
much
faster
to
just
tell
the
mds.
An
entire
directory
tree
can
go
away
and
that'll.
That's
a
workload
that
we'd
like
to
support
through
a
new
recursive,
unlink,
rpc
and
probably
that'll,
be
exposed
to
the
user,
is
some
kind
of
dot
trash
directory
to
allow
applications
to
to
be
able
to
do
that
without
linking
to
lips
ffs.
A
A
A
That's
in
pacific
there's,
a
link
to
the
blog
post
for
libsev
sql
lite
in
the
slides,
libstep
ffs
sqlite
will
function
similarly
and
that
it
allows
you
to
put
a
sqlite
database
on
cephfs
without
actually
mounting
cfs
using
the
chronoclient
or
cephus.
So
can
speak
this
fs
protocol
and
and
avoid
doing
any
mounts.
A
Then
we've
also
got
the
mds
memory
target
and
this
is
another
configuration
companion
to
the
the
osd
memory
target
variable
and
this
is
to
improve
how
the
mds
utilizes
the
memory
by
monitoring
its
own
memory,
use
and
then
adjusting
the
its
own
cache
as
appropriate
in
order
to
to
meet
the
desired
memory
target.
We
have
some
code.
A
That's
already
been
worked
on
that
just
needs
picked
up
and
polish
for
frequency
to
get
this
in
and
then
first
ffs
multi-site
replication,
currently
we're
working
on
more
testing
for
the
h,
a
components
of
the
cepheus
mirror.
That's
already
present
and
adding
active
active
support.
Both
of
those
features
were
planning
to
back
port
to
pacific.
A
You
won't
need
to
wait
for
quincy
for
those
to
be
available
and
make
it
more
automatic
to
set
up
snapshots
and
sync
it
to
the
to
the
remote
cluster
to
make
that
interface
a
little
cleaner
and
some
of
the
other
things
we're
looking
at
is
some
other
sophisticated
models
for
for
actually
doing
multi-site
replication
without
any
firm
plans
of
doing
this.
For
for
quincy,
look
at
potentially
bi-directional
or
loosely
eventually
consistent
type,
synchronization
mechanisms
and
some
kind
of
simple
conflict
resolution
behavior
in
tandem
with
bi-directional.
A
B
B
Okay,
the
other.
The
other
thing
I
was
wondering
is:
whenever
there's
like
a
it
happens
very
rarely,
but
whenever
users
hit
like
a
a
crash
of
an
mds
and
then
the
journal
can't
be
replayed
and
then
they
have
to
enter
into
the
disaster
recovery
procedure.
This
is
like
extremely
scary.
I'm
wondering
if
there's
any
ideas
to
make
that
somehow
less
scary
and
maybe
even
more
automatic,
something
like.
A
A
There
are
tools
to
do
that,
of
course,
but
which
tools
to
use
is
not
always
clear.
I
think,
as
far
as
improving
the
usability
of
of
cefs,
we
could
go
a
long
way
to
be
more
clear
about
what
the
kind
of
metadata
damage
we've
discovered
and
in
places
where
we
do
said
that
there
should
be
some
suggestions
on
on
where
to
look.