xlv_mgr(1M)xlv_mgr(1M)NAMExlv_mgr - administers XLV logical volume objects and their disk labels
SYNOPSISxlv_mgr [ -r root ] [ -c cmdstring ] [ -v ] [ -x ] [ -R ]
DESCRIPTIONxlv_mgr displays and modifies existing XLV objects (volumes, plexes,
volume elements, and XLV disk labels). xlv_mgr can operate on XLV
volumes even while they are mounted and in use.
xlv_mgr supports the following command line options:
-r root Use root as the root directory. This is used in the miniroot
when / is mounted as /root.
-c cmdstring
Command line option. Causes xlv_mgr to go into command line
mode and use cmdstring as the command input. Multiple
instances of -c are accumulated.
-v Verbose option. Causes xlv_mgr to generate more detailed
output.
-x Expert mode. Provides additional functions.
-R Do not read the XLV configuration information from the disks at
the time xlv_mgr is invoked. This allows xlv_mgr to quickly
startup. The XLV configuration information can be read from
the disks at a later time with the reset command.
Commands that pertain to plexes are displayed only when the system has
been licensed for the plexing portion of XLV.
xlv_mgr provides several types of operations: attach, detach, delete,
change, script, and show:
attach Add an XLV object to another XLV object. You can add a volume
element to a plex or plex to a volume. The volume element or
plex to be added must first be created using xlv_make(1M).
detach Separate a part of an XLV object and make it an independent
(standalone) XLV object. For example, if you detach a plex
from a plexed volume, that plex is separated from the volume
and made into a standalone plex. The original volume then has
one less plex.
delete Delete an entire XLV object.
script Generate the xlv_make commands required to create some or all
XLV objects.
Page 1
xlv_mgr(1M)xlv_mgr(1M)
show Display the list of XLV objects on the system and their
structure.
change Change an attribute associated with can XLV object.
The commands are:
show [-long][-verbose] all
Displays all known XLV objects by name and type. The -long option
causes more information about each XLV object to be displayed. The
-verbose displays more detailed information, such as the uuid. The
following is an example of the output of this command:
xlv_mgr> show all
Volume: root_vol (complete)
Volume: db1 (complete)
Volume Element: ve12
Plex: plex2
show [-short][-verbose] kernel [volume_name]
Displays all XLV objects or the specified volume_name configured
into the running kernel. The only XLV objects in the kernel are
volumes. Standalone plexes and volume elements are not viable
objects in the kernel because they cannot be used. The -short
option displays terse information on each volume. The -verbose
displays more detailed information on each volume.
show [-long][-verbose] labels [device_volume_header]
Displays XLV disk labels on all disks or the specified
device_volume_header. The -long option displays the secondary
label.
show config
Displays XLV software configuration information about the running
kernel. Included are statistics on the XLV memory pools for all
plexed volumes (if support is present) and all volume elements. For
example:
xlv_mgr> show config
Allocated subvol locks: 30 locks in use: 8
Plexing license: present
Plexing support: present
Statistic Collection: off
Plex buffer pool statistics:
maximum concurrent I/O's 13; I/O buffer size 1016 bytes
buffer pool size 13.21KB; maximum size 4.00GB
pool hits 1121; misses 141; waits 0; resized 4 times
memory growth rate 50%; maximum miss rate 10%
Volume Element buffer pool statistics:
Page 2
xlv_mgr(1M)xlv_mgr(1M)
maximum concurrent I/O's 53; I/O buffer size 1.48KB
buffer pool size 80.32KB; maximum size 4.00GB
pool hits 1636; misses 225; waits 0; resized 5 times
memory growth rate 50%; maximum miss rate 10%
Maximum subvol block number: 0x7fffffff
The Statistic Collection tag indicates if statistics gathering is
enabled (on) or disabled (off).
In the pool statistics, hits imply an efficient I/O path and misses
suggest a somewhat slower path. When the maximum miss rate is
exceeded, the buffer pool is grown by the growth rate. The buffer
pool size is limited to maximum size. The maximum concurrent I/O's
gives an upper bound on the number of efficient I/Os possible, and
the I/O buffer size is the amount of memory dedicated for each I/O
request.
show [-verbose] object object_name
Displays detailed information on an XLV object object_name. The
information includes all the XLV parameters and the disk partitions
that make up the object.
In the example below, the volume named db1 has one subvolume of type
data that contains two plexes. The first plex has two volume
elements, while the second plex only has one volume element. The
first volume element in each plex covers the same range of disk
blocks. For each volume element, xlv_mgr displays the partitions
that make up the volume element, the size of the partition, and the
range of this volume's disk blocks that map to the volume element.
For example:
xlv_mgr> show object db1
VOL db1 (complete)
VE db1.data.0.0 [active]
start=0, end=1100799, (cat)grp_size=1
/dev/dsk/dks1d4s0 (1100800 blks)
VE db1.data.0.1 [active]
start=1100800, end=2201599, (cat)grp_size=1
/dev/dsk/dks1d4s1 (1100800 blks)
VE db1.data.1.0 [active]
start=0, end=1100799, (cat)grp_size=1
/dev/dsk/dks1d4s2 (1100800 blks)
show stat [subvolume]
Displays statistics gathered for either all subvolumes or the
specified subvolume. For example:
xlv_mgr> show stat root.data
Subvolume 0 (root.data):
read ops: 668, read blocks: 286015
write ops: 2025, write blocks: 305508
Page 3
xlv_mgr(1M)xlv_mgr(1M)
The above example shows the number of read/write operations and
read/write blocks going to the data subvolume of the volume root.
The following example shows the statistics for subvolume 6 which has
a striped volume element.
xlv_mgr> show stat 6
Subvolume 6 (rickey.data):
read ops: 300, read blocks: 2457600
write ops: 300, write blocks: 2457600
stripe ops: 600, total units: 19200
largest single i/o: 32 stripe units, frequency: 600
aligned < stripe width; ends on stripe unit: 0
aligned > stripe width; ends on stripe unit: 600
aligned = stripe width; ends on stripe unit: 0
aligned > or < stripe width; doesn't end on stripe unit: 0
unaligned < stripe width; ends on stripe unit: 0
unaligned > stripe width; ends on stripe unit: 0
unaligned = stripe width; doesn't end on stripe unit: 0
unaligned > or < stripe width; doesn't end on stripe unit: 0
A stripe width is composed of the product of the stripe unit and the
number of disks comprising the stripe. The stripe unit determines
the number of blocks to write to one disk before writing to the
next. The stripe statistics are:
stripe ops The number of operations issued to the
subvolume's striped volume elements.
Depending on the volume geometry, and whether
or not the subvolume is plexed, this may not
match the number of read and write operations.
total units The cumulative count of all stripe units
involved in stripe operations to the
subvolume.
largest single i/o Keeps track of the largest I/O size issued to
the subvolume measured in stripe units.
frequency The number of times the largest I/O was
issued.
There are three parameters for evaluating how an I/O spans a striped
volume:
aligned/unaligned Indicates whether or not the start address of
the I/O begins on a stripe unit boundary. If
an I/O doesn't start on a boundary, the stripe
unit is used inefficiently.
Page 4
xlv_mgr(1M)xlv_mgr(1M)
< stripe width
> stripe width
= stripe width Specifies if the transfer is less than a
stripe width's worth of data, more than a
stripe width, or an even multiple of the
stripe width size. Transfers of full stripe
widths are optimal since all disks are
accessed evenly. Transfers of more or less
than a stripe width are less optimal due to
uneven drive access patterns.
doesn't end on a stripe unit
ends on a stripe unit When an I/O ends on a stripe unit, the next
sequential I/O will start aligned on a stripe
unit boundary. If it doesn't end on a stripe
unit, then the stripe is used inefficiently
since a sequential access will require that
particular unit to be accessed multiple times.
attach ve source dest-plex
attach ve source volume.{data|log|rt}.N
The command appends standalone volume element object source to the
end of destination plex. This enables you to grow a plex or volume
by adding a volume element to the end of a plex. You can use this
in conjunction with xfs_growfs(1M) to grow an XFS filesystem without
unmounting it.
Suppose that you have a volume element, spareve, that contains a
single disk partition /dev/dsk/dks1d4s2. The following command
appends it to plex 0 of the data subvolume of volume db1:
xlv_mgr> attach ve spareve db1.data.0
xlv_mgr> show object db1
VOL db1 (complete)
VE db1.data.0.0 [active]
start=0, end=1100799, (cat)grp_size=1
/dev/dsk/dks1d4s0 (1100800 blks)
VE db1.data.0.1 [active]
start=1100800, end=2201599, (cat)grp_size=1
/dev/dsk/dks1d4s1 (1100800 blks)
VE db1.data.0.2 [active]
start=2201600, end=3302399, (cat)grp_size=1
/dev/dsk/dks1d4s2 (1100800 blks)
attach plex source volume.{data|log|rt}
Appends standalone plex object source to existing volume volume.
This command creates duplicate copies of the data on the volume for
greater reliability. This operation is sometimes called mirroring.
After the plex has been added, xlv_mgr automatically initiates a
plex revive operation; this copies the data from the original XLV
plexes to the newly added plex so that the plex holds the same data
as the original plexes in the volume. The following appends a plex
Page 5
xlv_mgr(1M)xlv_mgr(1M)
named plex2 to the data subvolume of volume db1:
xlv_mgr> attach plex plex2 db1.data
Use the show object command to display volume db1 and see that the
disk partitions that were part of plex2 are now a component of db2.
plex2 no longer exists as a standalone plex since it was merged into
volume db1.
insert ve source vol.{data|log|rt}.N
insert ve source plex.N
Inserts standalone volume element object source into the destination
plex object. This enables you to add a volume element into a gap in
a plex.
xlv_mgr requires that the destination be a fully qualified XLV
pathname (for example, movies.data.0). The pathname must specify
the relative position within the plex to insert the volume element.
(The first volume element in a plex is at position 0.) The plex to
be operated on can be a standalone plex or a part of a volume. If
the plex is part of a volume, the volume, subvolume, and plex must
be specified. In the example below it is volume test. The
following example inserts a volume element ve5 into a gap in the
volume test. There is a gap because the first volume element starts
at block number 76200. First display the configuration of test and
ve5 before inserting ve5 into test.
xlv_mgr> show object test
VOL test (has holes)
VE test.data.0.0 [active]
start=76200, end=152399, (cat)grp_size=1
/dev/dsk/dks0d2s1 (76200 blks)
VE test.data.0.1 [active]
start=152400, end=228599, (cat)grp_size=1
/dev/dsk/dks0d2s2 (76200 blks)
xlv_mgr> show object ve5
VE ve5 [empty]
start=0, end=76199, (cat)grp_size=1
/dev/dsk/dks0d2s5 (76200 blks)
xlv_mgr> insert ve ve5 test.data.0
xlv_mgr> show object test
VOL test (complete)
VE test.data.0.0 [stale]
start=0, end=76199, (cat)grp_size=1
/dev/dsk/dks0d2s5 (76200 blks)
VE test.data.0.1 [active]
Page 6
xlv_mgr(1M)xlv_mgr(1M)
start=76200, end=152399, (cat)grp_size=1
/dev/dsk/dks0d2s1 (76200 blks)
VE test.data.0.2 [active]
start=152400, end=228599, (cat)grp_size=1
/dev/dsk/dks0d2s2 (76200 blks)
detach [-force] ve plex.N ve-object
detach [-force] ve volume.{data|log|rt}.N ve-object
Removes specified volume element from its parent object and save it
as ve-object. This command separates a volume element from its
parent plex. This volume element can later be added to some other
XLV object. The plex from which the volume element is removed can
be a standalone plex or part of a volume. The detached volume
element becomes a standalone XLV volume element object. You must
specify the fully qualified pathname of the volume element to be
detached and the name to be given to the detached volume element.
The -force option forces the detach when the the parent object is
missing any pieces. The detach operation leaves the volume element
intact.
detach [-force] plex volname.{data|log|rt}.plexno plexobject
This command removes the specified plex from its parent object and
saves it as plexobject. The -force option forces the detach when
the the parent object is missing any pieces. This new standalone
plex can later be added back to a volume via the attach plex
command.
The following example shows how to detach the first plex from a
volume:
xlv_mgr> detach plex db1.data.0 savedplex
delete object name
Deletes the object name. This command enables you to delete a
volume, a standalone plex, or a standalone volume element. The XLV
configuration is removed from the disks that make up the XLV object.
Because the XLV configuration information is stored in the volume
header (see vh(7M)), this command does not affect any user data that
may have been written to the user disk partitions.
delete all[_labels]
An expert command, this command deletes the XLV labels from all
disks on the local system. You might want to do this to initialize
all the disks on a new system and ensure that there is no leftover
XLV configuration information on the disks. Note that this is a
very dangerous operation. Deleting the disk labels destroys all of
the XLV objects on the system.
delete label device_volume_header
An expert command, this command deletes the XLV disk label from the
named device_volume_header.
Page 7
xlv_mgr(1M)xlv_mgr(1M)
change name object_name newname
This command renames the given XLV object object_name to newname.
The following example shows how to rename an object small to big.
xlv_mgr> change name small big
change nodename name object ...
This command changes the nodename associated with the named objects.
The following example shows how to set the node name for the volume
db1 to homestead.
xlv_mgr> change nodename homestead db1
change online vol.{data|log|rt}.N.N
change offline vol.{data|log|rt}.N.N
This command transitions the specified volume element online or
offline.
change stat on
change stat off
Expert commands to enable or disable statistics gathering. The
default setting for statistics gathering is specified in the
configuration file /var/sysgen/master.d/xlv.
change type ve|plex|vol object
This command changes the type of the given object.
The following example shows how to change a standalone plex object
sa_plex to a volume and then rename the volume to backup_vol.
xlv_mgr> change type vol sa_plex
xlv_mgr> change name sa_plex backup_vol
change ve_start start_block sa_ve
This command changes the start address of a standalone volume
element. This is useful to aid in detaching a volume element from
one object and arbitrarily inserting it in another.
change plexmem max-pool-i/os growth% maximum-miss% [maximum-size]
change vemem max-pool-i/os growth% maximum-miss% [maximum-size]
An expert command, these two commands allow you to modify the
parameters for the two XLV memory/buffer pools.
When servicing an I/O request, there are two types of memory
allocated. The first is for plexed volumes, if plexing support is
present, and the second is for the underlying volume elements. If
no memory available in the respective memory pool, XLV gets memory
from the system general purpose memory allocator. By changing the
maximum number of concurrent I/O max-pool-i/os, you can increase the
efficiency of an I/O request because memory taken from the pool is
Page 8
xlv_mgr(1M)xlv_mgr(1M)
more efficient than using the general purpose allocator. Changing
the growth percentage growth% alters how fast the pool grows when
the number of misses exceeds the miss percentage maximum-miss%. The
maximum-size parameter is expressed in kilobyte units and is used to
limit the size of the memory pool.
Note that any changes to the pool parameters are only for life of
the running system. The changes are not kept across system
restarts.
reset
Reinitializes xlv_mgr data structures by rereading all the XLV
configuration information from all the disks.
reset stat [subvolume]
An expert command to clear the statistics of either all subvolumes
or the named subvolume.
script [-write filename] object name
script [-write filename] all
Generates the required xlv_make commands to create the named object
or all objects. When the -write option is specified, the xlv_make
commands are saved into filename.
help Displays a summary of xlv_mgr commands.
? Same as help.
sh Fork a shell.
quit Terminate this session.
EXAMPLES
These examples show the making of some XLV objects and the growing and
plexing of a volume. The resulting volume configuration is saved to a
xlv_make(1M) input file.
Use xlv_make(1M) to create a volume named bigvolume.
xlv_make> vol bigvolume
bigvolume
xlv_make> data
bigvolume.data
xlv_make> plex
bigvolume.data.0
xlv_make> ve dks131d3s7
bigvolume.data.0.0
xlv_make> end
Object specification completed
xlv_make> exit
Newly created objects will be written to disk.
Is this what you want?(yes) yes
Page 9
xlv_mgr(1M)xlv_mgr(1M)
Invoking xlv_assemble
Create a standalone volume element spare_ve.
# xlv_make
xlv_make> ve spare_ve dks131d4s7
spare_ve
xlv_make> end
Object specification completed
xlv_make> exit
Newly created objects will be written to disk.
Is this what you want?(yes) yes
Invoking xlv_assemble
Use the xlv_mgr attach ve command to grow the volume bigvolume by
appending spare_ve to plex 0 of the data subvolume.
# xlv_mgr
xlv_mgr> attach ve spare_ve bigvolume.data.0
xlv_mgr> exit
Create a standalone plex spare_plex which can be used to completely
mirror the volume bigvolume.
xlv_make> plex spare_plex
spare_plex
xlv_make> ve dks133d3s7
spare_plex.0
xlv_make> ve dks133d4s7
spare_plex.1
xlv_make> end
Object specification completed
xlv_make> exit
Newly created objects will be written to disk.
Is this what you want?(yes) yes
Invoking xlv_assemble
Use the xlv_mgr attach plex command to mirror the volume bigvolume by
adding plex spare_plex to the data subvolume.
# xlv_mgr
xlv_mgr> attach plex spare_plex bigvolume.data
xlv_mgr> exit
Save the volume configuration to a file.
# xlv_mgr
xlv_mgr> script -write /etc/xlv_make.bigvolume.input object bigvolume
xlv_mgr> exit
Page 10
xlv_mgr(1M)xlv_mgr(1M)SEE ALSOxlv_assemble(1M), xlv_make(1M), xlv_plexd(1M), xlv_shutdown(1M), xlv(7M).
Tcl and the Tk Toolkit by John K. Ousterhout, Addison-Wesley, 1994.
NOTESxlv_mgr operations modify both the XLV disk labels and the kernel data
structures as appropriate. This means that you do not need to run
xlv_assemble(1M) for your changes to take effect. The only exceptions
are the XLV label deleting commands delete all_labels and delete label,
which effect only the disk labels.
xlv_mgr automatically initiates plex revive operations (see
xlv_plexd(1M)) as required after adding a new plex to a volume or a
volume element to a plexed volume.
You should be root when running xlv_mgr. Otherwise you have limited
functionality.
Page 11
