System Administration Commands iiadm(1M)
NAME
iiadm - command-line interface to control Sun StorageTek
Availability Suite Point-in-Time Copy operations
SYNOPSIS
iiadm -e {ind shd} mastervol shadowvol bitmapvol
iiadm -ne ind mastervol shadowvol bitmapvol
iiadm [-p] [-n] {-c -u} {s m} volumeset
iiadm [-adDilR] volumeset
iiadm [-p] [-n] -w volumeset
iiadm [-hilLv]
iiadm -P delay units volumeset
iiadm -P volumeset
iiadm -A overflowvol volumeset
iiadm [-OQ] overflowvol
iiadm -E volumeset
iiadm [-IJ] volumeset bitmap
iiadm -g groupname [-aAcdDeEilLmPRuw]
iiadm [-C] clustertag [options]
DESCRIPTION
Point-in-Time Copy software is a point-in-time snapshot
feature of the Solaris operating system.
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System Administration Commands iiadm(1M)
A Point-in-Time Copy snapshot is an instantly-available,
time-fixed, replicated view of a momentarily quiesced
volume. Once a snapshot is taken, Point-in-Time Copy
software allows immediate read/write access to both the mas-
ter and shadow volume data.
Point-in-Time Copy software tracks the differences between
the master and shadow volumes (caused by writes) from the
moment that the snapshot was established. This capability
allows applications accessing the master volume's data to
move forward in time independently of applications accessing
the shadow volume's data, and vice-versa.
The Point-in-Time Copy software's tracking of differences
between the master and shadow volumes facilitates a fast
resynchronization or a full copy at a later time. The volume
resynchronization can occur from either shadow to master or
master to shadow.
Instantly after the point-in-time is (re-)established
(either when the CLI prompt returns or the next shell script
command is read), the master volume can be remounted or the
applications using them can be resumed. Also, the shadow
volume can be mounted and immediately accessed.
The iiadm command line utility performs only one action per
command invocation. Because of this, you cannot combine mul-
tiple options, except in combination with the following
overall command modifiers:
o If no action item is entered, iiadm displays the
list of Point-in-Time Copy sets (non-suspended)
currently configured. If more than one action item,
or an incorrectly specified action item is entered,
iiadm displays the specific error message to
stderr, followed by a brief usage summary.
o For the Point-in-Time Copy options ENABLE (-e),
COPY (-c) and UPDATE (-u), there are two associated
shadow volume selection qualifiers, {inddep}, that
are used to specify the type of Point-in-Time Copy
volume set to create.
An independent (ind) snapshot causes Point-in-Time Copy
software to perform a full volume copy operation from the
master to the shadow. When the copy completes, the shadow
volume data is identical to the master volume data at the
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System Administration Commands iiadm(1M)
moment that it was established. Create an independent shadow
if you require two physical copies of the data. An indepen-
dent shadow volume must be the same size or greater than the
size of the master volume. Sun recommends that the master
and shadow volumes be the same size for environments where
resynchronization from shadow to master is a consideration.
A dependent (dep) snapshot causes Point-in-Time Copy
software not to perform a full volume copy. The resulting
shadow volume relies on the master volume for all unmodified
data blocks, which are not copied until requested. Create a
dependent shadow when you do not require two physical copies
of the data. A dependent shadow volume can be either the
same size or smaller than the master volume. A smaller sha-
dow volume is called a Compact Dependent Shadow Volume, and
is typically used when the amount of change that occurs to a
Point-in-Time Copy volume set is small compared to the
entire size of the master volume.
The following syntax allows you to create an exportable
independent shadow volume in a Sun Cluster environment:
# iiadm -ne ind master shadow bitmap
An issue arises when using a Compact Dependent Shadow Volume
in that its size is established at the time that the Point-
in-Time Copy volume set is enabled. If the amount of change
to the entire volume set over the duration of its usage
exceeds the space allocated for the shadow volume, the sha-
dow volume is marked as out of space. It is possible to read
from the shadow volume even after it is out of space, until
a portion of the data for which there was no room is
requested. Once that happens, the read fails and the shadow
volume is marked offline.
To address this issue, Point-in-Time Copy supports the abil-
ity to associate an overflow volume to an existing Point-
in-Time Copy dependent volume set. Thus, if the size of the
Compact Dependent Shadow Volume is too small, or an
unscheduled amount of change occurs to the volume set,
changed data can be redirected to the associated overflow
volume. To facilitate efficient usage of this overflow
volume, it can be associated with multiple Point-in-Time
Copy volume sets on an as-needed basis.
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Considerations
Prior to invoking an Point-in-Time Copy enable, copy or
update operation, Point-in-Time Copy assures that the shadow
volume is not mounted, to prevent a file system panic from
occurring. Also, it is suggested that you either unmount or
suspend (quiesce) all applications using the master volume,
for only the instant when the point-in-time snapshot is
taken. This assures that an atomically consistent point-in-
time snapshot is taken.
It is suggested that, if the master volume was suspended
rather than unmounted, the new point-in-time shadow volume's
integrity be validated using volume validation utilities,
such as fsck(1M). The reason is that Point-in-Time Copy has
made a point-in-time copy of a mounted master volume to an
unmounted shadow volume. During the mounting of the shadow
volume, the file system detects that it is in the mounted
state. Typically this state occurs only when a system
crashes, so the file system attempts to validate the
integrity of the volume assuming a system failure occurred,
not an Point-in-Time Copy.
ENVIRONMENT OPTIONS
The iibitmap variable in the /usr/kernel/drv/ii.conf confi-
guration file determines the bitmap volume operational
semantics as follows:
0 Indicates that the bitmap is maintained in
memory only or resume operation.
1 Indicates that the bitmap is maintained in
memory and on disk. This is the default value.
If a system failure occurrs while using iibitmap=0, the
shadow volume might be inconsistent and fast resynchroniza-
tion would not be possible.
If Point-in-Time Copy is used in conjunction with the Net-
work Storage component Remote Mirror or in a Sun Cluster,
set iibitmap=1.
The iidebug variable in the /usr/kernel/drv/ii.conf confi-
guration file determines the amount of information logging
that is output to the system console /dev/console during
Point-in-Time Copy processing.
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0 Indicates that no logging is sent to the system
console.
1 Indicates that informational logging is sent to
the system console.
2 Indicates that developmental logging is sent to
the system console.
OPTIONS
The iiadm utility supports the following options.
-e{inddep} mastervol shadowvol bitmapvol
Enable Point-in-Time Copy for the specified master, sha-
dow, and bitmap volumes.
The enable shadow set processing assures that the speci-
fied volumes are accessible, that the shadowvol is not
mounted, and that the bitmapvol is correctly sized for
the type of shadow set being created. Additionally, it
assures that the volumes are under control of the SV
driver ( if they are not, it puts them there), initial-
izes the bitmap volume, and, if the volume set is an
independent shadow set, a full copy operation is ini-
tiated.
On a successful enable, Point-in-Time Copy stores the
specified mastervol, shadowvol and bitmapvol names,
plus the enabling type (ind or dep), into the Point-in-
Time Copy configuration store. The configuration store
contains all currently configured Point-in-Time Copy
Volume Sets and their associated configuration attri-
butes. (See discussion above on independent and depen-
dent shadow volume semantics.)
mastervol is the volume from which a point-in-time
snapshot is made.
shadowvol is the volume that contains the point-in-time
snapshot.
bitmapvol is used for tracking differences between the
shadow and master volumes. When Point-in-Time Copy sha-
dow operations are suspended or resumed, the bitmap
volume (maintained in kernel memory) can be stored in or
retrieved from permanent storage. The storage associated
with the bitmap volume should be as redundant as that of
the shadow volume storage.
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The shadowvol name is the name that the Point-in-Time
Copy Shadow Set is known by for all iiadm options
requiring specification of a volumeset name.
-d volumeset
Disable the Point-in-Time Copy volume set associated
with the specified volumeset.
If Point-in-Time Copy was running in independent mode as
specified in the -e ind options, above, the shadow
volume data contains the same data as it did before it
was disabled (assuming no writes have occurred). Users
can access the master and shadow volumes, as they are
now standalone point-in-time copies.
During the time that the full copy is active, an
independent volume operates as though it is a dependent
volume. To assure that the volume is no longer in full
copy mode, issue the following command to wait for the
full copy to complete:
# iiadm -w volumeset
[-p] -u s volumeset
Update the shadow volume from the master.
Updates a point-in-time copy of the master volume to the
shadow volume. volumeset is the Point-in-Time Copy sha-
dow set containing the master and shadow volumes. This
option provides a fast resynchronization of the shadow
volume, creating an incremental copy of the master. This
update copies all 32KB segments flagged as different
between the master and shadow volumes. It does not copy
all master volume data, only changed data. While the
data is being copied, the shadow is dependent upon the
master volume.
Before using this option, momentarily quiesce the work-
load to the volumes; stop the host application from
writing to the volumes. This ensures that the point-in-
time data is consistent. You can visually check the
status of this copy or update operation with iiadm -i
volumeset, or interactively (by means of a shell or
script) with iiadm -w volumeset, before using the tar-
get volume for any other operations.
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This command supports PID (Process IDentifier) locking,
by using the option -p, iiadm -p -u s. Enabling this
option prevents other processes from taking a new
point-in-time snapshot, thus invalidating prior point-
in-time data.
[-p] [-n] -u m volumeset
Updates a point-in-time copy of the master volume from
the shadow. volumeset is the Point-in-Time Copy volume
set containing the master and shadow. This option pro-
vides a fast resynchronization of the master volume,
creating an incremental copy of the shadow. This update
copies all 32KB segments flagged as different between
the master and shadow volumes. It does not copy all sha-
dow volume data, only changed data. While the data is
being copied, the master is dependent upon the shadow
volume.
Before using this option, momentarily quiesce the work-
load to the volumes; stop the host application from
writing to the volumes. This ensures that the point-in-
time data is consistent. You can visually check the
status of this copy or update operation with iiadm -i
volumeset, or interactively (by means of a shell or
script) with iiadm -w volumeset, before using the tar-
get volume for any other operations.
This command is query enabled to prevent accidentally
overwriting the data on a master volume. When this com-
mand option is used in scripts, add the -n option to
prevent the query from occurring.
This command supports PID (Process IDentifier) locking,
by using the option -p, iiadm -p -u m. Enabling this
option prevents other processes from taking a new
point-in-time snapshot, thus invalidating prior point-
in-time data.
[-p] -c s volumeset
Copy the master volume to the shadow.
Creates a point-in-time copy of the master volume to the
shadow volume. volumeset is the Point-in-Time Copy
volume set containing the master and shadow. This option
writes all data in the point-in-time copy of the master
volume to the shadow volume. While the data is being
copied from master to shadow, the shadow is dependent on
the master volume.
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This option performs a full volume copy. Use iiadm -u s
unless the integrity of the data on the independent sha-
dow volume is in doubt. Otherwise, use this option to
synchronize the master and shadow volumes; that is, make
the data on each volume match.
Before using this option, momentarily quiesce the work-
load to the volumes; stop the host application from
writing to the volumes. This ensures that the point-in-
time data is consistent. You can visually check the
status of this copy or update operation with iiadm -i
volumeset, or interactively (by means of a shell or
script) with iiadm -w volumeset, before using the tar-
get volume for any other operations.
This command supports PID (Process IDentifier) locking,
by using the -p option, iiadm -p -c s. Enabling this
option prevents other processes from taking a new
point-in-time snapshot, thus invalidating prior point-
in-time data.
-c m volumeset
Copy the shadow volume to the master.
Creates a point-in-time copy of the shadow volume to the
master volume. volumeset is the Point-in-Time Copy
volume set containing the master and shadow volumes.
This option writes all data in the point-in-time copy of
the shadow volume to the master volume. While the data
is being copied from the shadow to the master, the mas-
ter is dependent upon the shadow volume.
This option performs a full volume copy. Use iiadm -u m
unless the integrity of the data on the independent mas-
ter is in doubt. Otherwise, use this option to synchron-
ize the master and shadow volumes; that is, make the
data on each volume match.
Before using this option, momentarily quiesce the work-
load to the volumes; stop the host application from
writing to the volumes. This ensures that the point-in-
time data is consistent. You can visually check the
status of this copy or update operation with iiadm -i
volumeset, or interactively (by means of a shell or
script) with iiadm -w volumeset, before using the tar-
get volume for any other operations.
This command is query-enabled to prevent accidentally
overwriting the data on a master volume. When this com-
mand option is used in scripts, add the -n option to
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prevent the query from occurring.
This command supports PID (Process IDentifier) locking,
by using the -p option, iiadm -p -c m. Enabling this
option prevents other processes from taking a new
point-in-time snapshot, thus invalidating prior point-
in-time data.
-a volumeset
Abort any current copy operation that might be active
between the master and shadow volumes. volumeset is the
Point-in-Time Copy volume set containing the master and
shadow volumes. After executing iiadm -a, the update or
copy to the target (master or shadow) volume is incom-
plete. The target volume is now a dependent copy of the
source volume. Reissue the update or copy command option
to resynchronize the volumes.
[-p] [-n] -w volumeset
Wait until any in-progress copy or update operation com-
pletes or is aborted. volumeset is the Point-in-Time
Copy volume set containing the master and shadow
volumes.
This option waits until the current Point-in-Time Copy
operation is complete, thus preventing a subsequent
iiadm command (from a shell or script) from executing.
Use this command option when you need to be sure the
copy or update operation has completed.
This command supports PID (Process IDentifier) unlock-
ing. If a prior copy or update, using a command iiadm -p
{-c-u} {ms}, was invoked with the -p option, upon com-
pletion of the wait processing, if the current PID was
the PID that locked the point-in-time data, this option
unlocks the data.
-i volumeset
Display status for the Point-in-Time Copy currently-
enabled or -suspended volume set. volumeset is the
Point-in-Time Copy volume set containing the master and
shadow volumes. If no volumeset is specified, status is
displayed for all Point-in-Time Copy volume sets that
are configured.
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-l
List all currently configured Point-in-Time Copy
volumes.
-O overflowvol
This option causes Point-in-Time Copy to initialize the
specified overflowvol for subsequent use as an overflow
volume in conjunction with Compact Dependent Shadow
Volumes. To facilitate efficient, shared usage of this
overflow volume, it can be associated with multiple
Point-in-Time Copy volume sets on an as-needed basis.
During initialization of the overflowvol, the initiator
of this option, must answer the following question:
"Initialize this overflow volume? yes/no" A response of
either "yes/no" is required before proceeding.
This option supports the -n option, so that the
requested action is performed without prompting. This
option is useful for inclusion in a script. The -n
option must be specified first. For example, "iiadm -nO
vol" is valid; "iiadm -On vol" is not.
Make sure you want to initialize the data on the speci-
fied overflowvol, especially when using the -n option.
-A overflowvol volumeset
This option enables the specified overflowvol, for sub-
sequent use as an overflow volume in a situation where
the size of the Compact Dependent Shadow Volume is too
small, or an unscheduled amount of change occurs to the
volume set. Overflow changed data would be redirected to
the associated overflow volume. volumeset is the
Point-in-Time Copy volume set containing the master and
shadow volumes.
If the overflowvol has not been initialized, this
option initializes the overflowvol (see -O option),
then attaches the overflowvol to the volumeset.
If overflowvol was previously initialized, this option
attaches the overflowvol to the volumeset.
This option supports the -n option, so that the
requested action is performed without prompting. This
option is useful for inclusion in a script. The -n
option must be specified first. For example, "iiadm -nA
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System Administration Commands iiadm(1M)
vol" is valid; "iiadm -An vol" is not.
Make sure you want to initialize the data on the speci-
fied overflowvol, especially when using the -n option.
-D volumeset
This option removes the overflow volume currently asso-
ciated with the specified volumeset. If the overflow
volume is currently in use by the volumeset, this
operation fails with an "Overflow volume still in use"
error message. To resolve this situation, perform one of
the operations described below on the volumeset. These
operations momentarily clear out all overflow writes
that are associated with this volume set.
abort(-a)
Abort copy operation.
disable(-d)
Dissolve the volume set.
update(-u)
Update the volume set.
-L
This option lists all overflow volumes which are associ-
ated with one or more volume sets.
-Q overflowvol
This option displays the current status of the
overflowvol.
-E volumeset
Export the independent shadow volume of the Point-in-
Time Copy volume set specified by volumeset. The shadow
volume is to be made available to another host for
read/write access, by means of an enabling technology,
such as multi-ported devices. This other host is
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responsible for maintaining a bitmap of differences that
is used to merge with locally recorded differences to
the master when the shadow volume is rejoined to its
master volume. While a shadow volume is exported it must
not be subject to an update or copy operation. Perform
an iiadm -w volumeset command prior to invoking an
export command.
-I volumeset bitmapvol
Import the independent shadow volume of the Point-in-
Time Copy volume set specified by volumeset. The shadow
volume must have been previously exported from a host by
means of an enabling technology, such as multi-ported
devices. The import operation causes this host to start
maintaining a bitmap of differences as the volume is
modified. The bitmapvol should not be the same as that
used when the shadow volume was originally formed into a
shadow group.
After the exported/imported independent shadow volume is
no longer needed by the other node, you must enter a
disable command so that the bitmapvol and its associ-
ated shadowvol are consistent, prior to performing a
join operation. For example,
# iiadm -d volumeset
-J volumeset bitmapvol
Join the volumeset, using the bitmapvol, with the mas-
ter volume set of the Point-in-Time Copy volume set. The
bitmap volume supplied is read and merged with the ori-
ginal volume to reconstruct the original volume set con-
sisting of the master, shadow, and bitmap volumes. The
bitmapvol to be merged is the one obtained on the node
that had imported the independent shadow volume. There
must be no write activity to the shadow volume on the
importing machine from the time the bitmap is copied
over until the shadow is once again imported.
-g groupname -m volumeset [volumeset2 ...]
Add one or more existing Point-in-Time Copy
volumeset(s) into a user specified groupname. This
association of one or more Point-in-Time Copy volume
sets in a group allows the list of iiadm options shown
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System Administration Commands iiadm(1M)
below to be performed on all volume sets within the
groupname as a whole.
Only the commands COPY (-c) and UPDATE (-u) are per-
formed atomically across all Point-in-Time Copy sets
within the group. All other grouped, iiadm commands are
performed sequentially on each member of the group.
The syntax of an iiadm group command is as follows:
iiadm -g groupname [options]
The options are as follows:
-a
Abort copy operation on all sets within groupname.
-A
Attach overflowvol to all sets within groupname.
-c {s m}
Copy shadow/master for all sets within groupname.
-D
Detach overflowvol from all sets within groupname.
-d
Disable all sets within groupname.
-E
Export all volume sets within groupname.
-i
Status of all volume sets within groupname.
-l
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List all volume sets within groupname.
-L
List all groups.
-n
Do not ask if an update of the master volume is what
the user really intended.
-P
Set parameters on all volume sets within groupname.
-R
Reset all volume sets within groupname.
-u {s m}
Update shadow/master for all sets within groupname.
-w
Wait for all volume sets within groupname.
-g -" " -m volumeset [volumeset2 ...]
Remove one or more existing Point-in-Time Copy
volumeset(s) from their currently associated
groupname. By default, or until moved into a user
specified groupname, all Point-in-Time Copy
volumeset(s) are in the blank (" ") group. This associ-
ation allows all the previously documented iiadm group
commands to be performed against the blank (" ") iiadm
groupname.
-C clustertag
This Point-in-Time Copy option is a modifier that limits
configuration operations to only those volumes belonging
to a Sun Cluster Resource Group, or Disk Group.
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In a Sun Cluster where the volume manager is Sun
Cluster-aware, iiadm automatically obtains the correct
Disk Group information, therefore this option is typi-
cally not required unless the volumes are part of an
encompassing Resource Group.
In a Sun Cluster where the volumes are accessible on the
local node only, the special clustertag of local is
used to indicate volumes that are not part of a Sun
Cluster Resource Group or Disk Group.
If "-L" is given as a the clustertag argument, then
iiadm lists all cluster tags associated with Point-in-
Time Copy.
This option is invalid when used on a Solaris system on
which the Sun Cluster package has not been installed or
configured.
-h
Prints the iiadm usage summary.
-v
Display the current version of the Point-in-Time Copy
software components.
Contact Sun Enterprise Services for assistance in using the
remaining commands in this section.
-P delay unit volumeset
Alter the Point-in-Time Copy volume set tuning parame-
ters for the specified volumeset to delay ticks, every
unit I/O's. Delay ranges from 2 to 10000 inclusive; unit
ranges from 100 to 60000 inclusive.
-R volume
After a volume has failed, Point-in-Time Copy places it
offline. After replacing the volume, place it back
online using this option. Associated dependent volumes
in the Point-in-Time Copy volume set are also placed
online. After the volume is placed online, this command
also starts any necessary point-in-time volume updates.
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EXIT STATUS
0 Command completed successfully.
>0 An error occurred.
ATRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
ATRIBUTE TYPE ATRIBUTE VALUE
Availability SUNWiir, SUNWiiu
Interface Stability Evolving
SEE ALSO
dscfg(1M), svadm(1M), ds.log(4), rdc.cf(4), attributes(5),
ii(7D), sv(7D)
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