
Chapter
10.
Disaster
recovery
using
Copy
Services
One
of
the
main
reasons
for
using
Copy
Services
functions
is
to
prepare
for
a
possible
disaster
by
backing
up,
copying,
and
mirroring
your
data
both
at
the
local
(production)
and
remote
sites.
Having
a
disaster
recovery
plan
can
ensure
that
critical
data
is
recoverable
at
the
time
of
a
disaster.
Because
most
disasters
are
unplanned,
your
disaster
recovery
plan
must
provide
a
way
that
allows
you
to
recover
your
applications
quickly,
and
more
importantly,
to
access
your
data.
Consistent
data
to
the
same
point-in-time
across
all
storage
units
is
vital
before
you
can
recover
your
data
at
a
backup
(normally
your
remote)
site.
Most
users
use
a
combination
of
remote
mirror
and
copy
and
point-in-time
copy
(FlashCopy)
features
to
form
a
comprehensive
enterprise
solution
for
disaster
recovery.
In
an
event
of
a
planned
event
or
unplanned
disaster,
you
can
use
failover
and
failback
modes
as
part
of
your
recovery
solution.
Failover
and
failback
modes
help
to
reduce
the
time
that
is
required
to
synchronize
remote
mirror
and
copy
volumes
after
you
switch
between
the
local
(or
production)
and
the
intermediate
or
remote
sites
during
planned
and
unplanned
outages.
Although
failover
transmits
no
data,
it
changes
the
status
of
a
device,
and
the
status
of
the
secondary
volume
changes
to
a
suspended
primary
volume.
The
Failback
command
transmits
data
and
can
go
in
either
direction
depending
on
which
device
the
Failback
command
is
issued
to.
Recovery
procedures
that
include
failover
and
failback
modes
use
remote
mirror
and
copy
functions,
such
as
Metro
Mirror,
Global
Copy,
Global
Mirror,
Metro/Global
Mirror,
and
FlashCopy.
Note:
See
the
IBM
System
Storage
DS8000
Command-Line
Interface
User’s
Guide
for
specific
disaster
recovery
tasks.
Data
consistency
can
be
achieved
using
the
following
methods:
Manually
using
external
software
(without
Global
Mirror)
If
you
use
Metro
Mirror,
Global
Copy,
and
FlashCopy
functions
to
create
a
consistent
and
restartable
copy
at
your
recovery
site,
you
must
do
a
manual
and
periodic
suspend
operation
at
your
local
site.
This
means
using
freeze
and
run
commands
together
with
external
automated
software
and
then
using
the
FlashCopy
function
to
make
a
consistent
copy
of
your
target
volume
for
backup
or
recovery
purposes.
(Automation
software
is
not
provided
with
the
storage
unit;
it
must
be
supplied
by
the
user.)
Note:
Freezing
of
the
data
is
done
at
the
same
point-in-time
across
all
links
and
all
storage
units.
Automatically
(with
Global
Mirror
and
FlashCopy)
If
you
use
a
two-site
Global
Mirror
or
a
three-site
Metro/Global
Mirror
configuration,
the
process
to
create
a
consistent
and
restartable
copy
at
your
intermediate
or
remote
site
is
done
using
an
automated
process,
with
minimal
or
no
interruption
to
your
applications.
Global
Mirror
operations
automate
the
process
of
continually
forming
consistency
groups.
It
combines
Global
Copy
and
FlashCopy
operations
to
provide
consistent
data
at
the
remote
site.
A
master
storage
unit
(along
with
subordinate
©
Copyright
IBM
Corp.
2004,
2008
153
Содержание DS8000 - ADDITIONAL INFORMATION
Страница 1: ...IBM System Storage DS8000 User s Guide V ersion 1 Release 4 SC26 7915 02 ...
Страница 2: ......
Страница 3: ...IBM System Storage DS8000 User s Guide V ersion 1 Release 4 SC26 7915 02 ...
Страница 8: ...vi DS8000 User s Guide ...
Страница 10: ...viii DS8000 User s Guide ...
Страница 12: ...x DS8000 User s Guide ...
Страница 14: ...xii DS8000 User s Guide ...
Страница 26: ...xxiv DS8000 User s Guide ...
Страница 106: ...78 DS8000 User s Guide ...
Страница 168: ...140 DS8000 User s Guide ...
Страница 202: ...174 DS8000 User s Guide ...
Страница 204: ...176 DS8000 User s Guide ...
Страница 212: ...184 DS8000 User s Guide ...
Страница 242: ...214 DS8000 User s Guide ...
Страница 246: ...218 DS8000 User s Guide ...
Страница 249: ......
Страница 250: ... Printed in USA SC26 7915 02 ...