"Note: The information contained in this article is structured as help information for the System Management Interface Tool (SMIT) and is not intended for use as a procedural or conceptual article."
The Logical Volume Manager advances data storage from the fixed physical limits of physical volumes (read-write disks) to a flexible system by allowing the size of logical volumes to span multiple physical volumes. Several physical volumes are grouped together into volume groups. Each volume group contains zero or more logical volumes.
A volume group is a collection of 1 to 32 physical volumes of varying size and type with a system wide unique name of up to 15 characters. Each system can have one to 255 volume groups configured.
Displays information about volume groups.
Lists only the active volume groups (those that are varied on). An active volume group is one that is available for use.
After installation, the system has one volume group (the root volume group) consisting of a base set of logical volumes required to start the system plus any other volume groups you specify to the install script. Other physical volumes not already in a volume group can be grouped together into additional volume groups
The volume group name. The name must be system-wide unique and can range from 1 to 15 characters.
The number of megabytes in each physical partition, where the Size value is expressed in units of megabytes from 1 through 1024. The Size value must be equal to a power of 2 (example 1, 2, 4, 8). The default value is 4 megabytes. The default number of physical partitions per physical volume is 1016. Thus, a volume group that contains a physical volume larger than 4.064 gigabytes must have a physical partition size greater than 4 megabytes.
The name of the physical volume. Physical volume names are typically in the form "hdiskx" where x is a system wide unique number. This name is assigned when the disk is detected for the first time on a system startup or when the system management commands are used at runtime to add a disk to the system.
Specifies whether the volume group is automatically activated during the system startup. If there is a volume group that is infrequently used, you may not want it activated at system startup because it uses kernel resources (memory).
Specifies whether to activate (vary on) the volume group after it is created.
Each physical volume has multiple physical partitions. Physical partitions for a logical volume must be contained within a single volume group. The size and number of physical partitions specified for the volume group can limit the size of a logical volume. A volume group can be changed, extended, or reduced.
Specifies whether the volume group is automatically activated during the system startup. If there is a volume group that is infrequently used, you may not want it activated at system startup because it uses kernel resources (memory).
Determines if the volume group is automatically varied off after losing its quorum of physical volumes. The default value is yes, meaning the volume group is automatically varied off after losing its quorum of physical volumes (51% of descriptor areas). Selecting no means the volume group stays active until it looses all of its physical volumes.
Add a new disk to an already existing volume group. The new disk becomes a member of the volume group and can be used to extend or move logical partitions to.
Deallocates the existing logical volume partitions and then deletes resultant empty logical volumes from the specified physical volumes.
Reorganizes the physical partition allocation for a volume group.
Specify a list of logical volumes that you wish to reorganize within the volume group specified. If no logical volumes are specified, the entire volume group is reorganized.
Displays information about volume groups.
If no flags are specified, the following status is displayed:
Volume group - Name of the volume group. Volume group names must be unique system wide and can range from 1 to 15 characters.
Volume group state - State of the volume group. If the volume group is activated with the "varyonvg" command, the state is either active/complete (indicating all physical volumes are active) or active/partial (indicating some physical volumes are not active). If the volume group is not activated with the "varyonvg" command, the state is inactive.
Permission - Access permission: read-only or read-write.
Max LVs - Maximum number of logical volumes allowed in the volume group.
LVs - Number of logical volumes currently in the volume group.
Open LVs - Number of logical volumes within the volume group that are currently open.
Total PVs - Total number of physical volumes within the volume group.
Active PVs - Number of physical volumes that are currently active.
VG identifier - The volume group identifier.
PP size - Size of each physical partition.
Total PPs - Total number of physical partitions within the volume group.
Free PPs - Number of physical partitions not allocated.
Alloc PPs - Number of physical partitions currently allocated to logical volumes.
Quorum - Number of physical volumes needed for a majority.
VGDS - Number of volume group descriptor areas within the volume group.
Auto-on - Automatic activation at IPL (yes or no).
-p - Lists the following information for each physical volume within the group specified by the VolumeGroup variable:
Physical volume - A physical volume within the group.
PVstate - State of the physical volume.
Total PPs - Total number of physical partitions on the physical volume.
Free PPs - Number of free physical partitions on the physical volume.
Distribution - The number of physical partitions allocated within each section of the physical volume: inside edge, back middle, center, front middle and outside edge of the physical volume.
-l - Lists the following information for each logical volume within the group specified by the VolumeGroup variable:
LV - A logical volume within the volume group.
Type - Logical volume type.
LPs - Number of logical partitions in the logical volume.
PPs - Number of physical partitions used by the logical volume.
PVs - Number of physical volumes used by the logical volume.
Logical volume state - State of the logical volume. Opened/stale indicates the logical volume is open but contains partitions that are not current. Opened/syncd indicates the logical volume is open and synchronized. Closed indicates the logical volume has not been opened.
Mount point - File system mount point for the logical volume, if applicable.
Deletes all logical volume data on the physical volume before removing the physical volume from the volume group. If a logical volume spans multiple physical volumes, the removal of any of those physical volumes may jeopardize the integrity of the entire logical volume.
Forces the volume group to be made active even though the volume group definition may be different on the physical volumes.
Physical partitions marked as stale must be updated to contain the same information as valid physical partitions. This process, called resynchronization, can be done at vary-on time or can be started any time while the system is running. Until the stale partitions have been rewritten with valid data, they are not used to satisfy read requests nor are they written to on write requests.
Physical partitions marked as stale must be updated to contain the same information as valid physical partitions. This process, called resynchronization, can be done at vary-on time or can be started any time while the system is running. Until the stale partitions have been rewritten with valid data, they are not used to satisfy read requests nor are they written to on write requests.
Makes the volume group available in System Management mode only. Logical volume commands can operate on the volume group, but no logical volumes can be opened for input or output.
Forcing activation of a volume group will allow the varyon to complete even if there is a lack of quorum (that is, missing or removed disks). Data integrity is not guaranteed.
The "varyoffvg" command deactivates the volume group specified by the VolumeGroup parameter along with its associated logical volumes. The logical volumes first must be closed. For example, if the logical volume contains a file system, it must be unmounted.
Puts the volume group into System Management mode, so that only logical volume commands can be used on the volume group. In this mode, no logical volume can be opened or accessed by users.
If a disk or group of disks is expected to be moved from one computer to another, this disk or group of disks should be installed into its own volume group. This volume group, and the disks that compose it, is then exported in its entirety from one computer and imported to another.
If a disk or group of disks is expected to be moved from one computer to another, this disk or group of disks should be installed into its own volume group. This volume group, and the disks that compose it, is then exported in its entirety from one computer and imported to another.
Specifies whether to activate the volume group after it is imported.
The major number of the volume group. The system kernel accesses devices, including volume groups, through a major and minor number combination. To see what major numbers are available on your system, use the "List" feature.
A logical volume is a collection of logical partitions made up of physical partitions, all contained in a single volume group. Logical volumes are expandable and can span several physical volumes in a volume group.
A physical volume is a read-write disk physically attached to a computer, with a permanently assigned system wide unique identifier. They are added to a volume group with the "extendvg" command and removed from a volume group with the "reducevg" command. When added to the volume group, physical volumes are partitioned into contiguous, equal-sized units of space called physical partitions.
A paging space is fixed-disk storage for information that is resident in virtual memory, but is not currently being accessed. When the amount of free real memory in the system is low, programs or data that have not been used recently are moved from real memory to paging space in order to free real memory for other activities.
Displays the characteristics of paging spaces. These characteristics are the paging space name, physical volume name, volume group name, size, percentage of the paging space used, whether the space is active or inactive, and whether the paging space is set to automatic.
Adds additional paging space to the system. Before the paging space can be used, it must be activated.
The volume group within which the logical volume for the paging space is to be made.
The size of the paging space and the logical volume to be made in logical partitions.
The physical volume of the volume group.
Activates the paging space immediately.
Specifies whether a paging space is to be used at the next system restart. Possible values are "yes" and "no". Specifying "yes" causes the system to use a paging space at the next system restart.
Allows you to change or display the attributes of a specific paging space.
The name of the paging space to be changed.
The number of logical partitions to add.
Removes a paging space from the system along with any logical volume on which it resides. The Paging Space parameter specifies the name of the paging space to be removed, which is actually the name of the logical volume on which the paging space resides.
For an NFS paging space, the Paging Space parameter specifies the name of the paging space to be removed. The device and its definition, which corresponds to this paging space, will be removed from the system. Nothing will be changed on the NFS server where the file that is used for paging actually resides.
Active paging spaces cannot be removed. To remove an active paging space, change its characteristics so that it is not configured at subsequent system restarts ("chps" command). Then, on the next system restart, the paging space is not active and it can be removed.
Specifies additional devices for paging and swapping.
You can also add physical volumes not already in a volume group to the root volume group, or to another volume group already created (using the "extendvg" command).
The volume group must be varied on in order to have access. During the vary-on process (activation), the Logical Volume Manager reads management data from the physical volumes defined in the volume group. This management data, which includes a Volume Group Descriptor Area (VGDA) and a Volume Group Status Area (VGSA), is stored on all physical volumes in the volume group for increased availability.
The Volume Group Descriptor Area contains information that describes all the logical volumes and all the physical volumes that belong to the volume group. The VGDA is managed by the LVM subroutine library. The Volume Group Status Area contains information about which physical partitions are stale and which physical volumes are missing (i.e., not available or active) at the current varyon. The VGSA is managed by the logical volume device driver in the kernel.
If the vary-on operation cannot access one or more of the physical volumes defined in the volume group, the command displays the names of all physical volumes defined for that volume group and whether it can access each physical volume. This helps users decide whether to continue operating with this volume group. For more information about the meanings of the physical volume status that can be displayed from the "varyonvg "command, refer to the "lvm_varyonvg" subroutine.
After a logical volume has been created, you can change its name, characteristics, and the number of physical partitions it contains.
Logical volume names must be system-wide unique and can range from 1 to 15 characters.
Number of logical partitions to be synchronized in parallel. You can specify between 1 and 32, depending on the machine, number of disks in the volume group, system resources, and volume group mode.
If you select "Yes", a good physical copy is selected and propagated to all other copies of the logical partition whether they are stale or not stale. This option is necessary when the logical volume does not have mirror write consistency.
Postpones writes for this volume group on other active concurrent cluster nodes until this sync operation is complete. This option is ignored if vary is set to off when the volume group is in concurrent mode.
Performs a foreground sync, background sync, or no sync of the volume group.
You can define a prefix, as long as it is not used by another device. The system generates a sequence number and creates the name from the prefix and the number. The prefix must be less than or equal to 13 characters.
Specifies whether to use Bad Block Relocation. Bad-Block Relocation redirects read-write requests from a disk block that can no longer retain data to one that can. The process is transparent; the application does not receive notice that requests directed to a physical block are actually serviced by a different block.
The Intra-Physical Volume Allocation Policy to use for choosing physical partitions on a physical volume.
"EDGE" and "INNER EDGE" - allocates partitions to the edges of the physical volume. These partitions have the slowest average seek times, which generally result in longer response times for any application that uses them.
"MIDDLE" and "INNER MIDDLE" - allocates partitions away from the edges of the physical volume and out of the center. These strategies allocate reasonably good locations for partitions with reasonably good average seek times. Most of the partitions on a physical volume are available for allocation using these strategies.
"CENTER" - allocates partitions to the center section of each physical volume. These partitions have the fastest average seek times, which generally result in the best response time for any application that uses them. There are fewer partitions on a physical volume that satisfy the "CENTER" strategy than for any other general strategy.
Specifies which Inter-Physical Volume Allocation Policy to use for choosing physical devices to allocate the physical partitions of a logical volume:
"MINIMUM" - with 1 copy specified, indicates that, if possible, one physical volume should contain all the physical partitions of this logical volume. Otherwise, use the minimum number possible consistent with other parameters. This policy provides the greatest reliability, without mirrored copies, for a logical volume.
"MINIMUM" - with 2 or 3 copies specified, indicates that as many physical volumes as there are copies should be used. Otherwise, the minimum number of physical volumes possible are used to hold all the physical partitions. At all times, the constraints imposed by other parameters are observed.
"MAXIMUM" - indicates that the physical partitions of this logical volume should be spread over as many physical volumes as possible. This is a performance-oriented option and should be used with copies to improve availability. If a logical volume is not copied and is spread across multiple physical volumes, the loss of any physical volume containing a physical partition from that logical volume is enough to cause the logical volume to be incomplete.
The scheduling policy to use for the mirrored (copies > 1) logical volume:
Sequential - performs copied write procedures in order: primary, secondary, tertiary. This policy waits for the write operation to complete for the previous physical partition before starting the write operation to the next one.
For read operations, the primary copy is read. If the read operation is unsuccessful, the next copy is read. The primary copy is then fixed by turning the read operation into a write operation with hardware relocation specified on the call to the physical device driver.
Parallel - starts the write operation for all the physical partitions in a logical partition at the same time. When the write operation to the physical partition that takes the longest to complete finishes, the write operation returns.
The Device Configuration Database may be inconsistent with the Logical Volume Manager because of system malfunction. If it is, you will receive a message from a logical volume command such as:
0516-322 The Device Configuration Database is inconsistent ...
OR
0516-306 Unable to find logical volume mylv in the Device Configuration Database. (where mylv is normally available)
Do not remove the "/dev" entries for volume groups or logical volumes. Do not change the database entries for volume groups or logical volumes using the object data manager.
During normal operations the Device Configuration Database remains consistent with the Logical Volume Manager information. If for some reason it is not consistent, the "varyonvg" command can be used to resynchronize the data for the specified volume group
Changes only the characteristics of a logical volume.
The logical volume label. The default label is None. The maximum size of the Label variable is 127 characters. Note: If the logical volume is going to be used as a journaled file system (jfs), then the jfs will use this field to store the mount point of the file system on the logical volume for future reference.
Sets the access permission to read-write or read-only.
Specifies whether to allow the relocation of the logical volume during reorganization
Select "Yes" to follow a strict allocation policy. Copies for a logical partition cannot share the same physical volume.
Select "No" to not follow a strict allocation policy. Copies for a logical partition can share the same physical volume.
Select "Superstrict" to follow a super strict allocation policy. Partitions allocated for one mirror cannot share a physical volume with the partitions from another mirror.
Specifies whether to verify all writes to the logical volume with a follow-up read.
Sets the maximum number of logical partitions that can be allocated to the logical volume.
The "chpv" command changes the state of the physical volume in a volume group by setting allocation permission to either allow or not allow allocation and by setting the availability to either available or removed. Characteristics for a physical volume remain in effect unless explicitly changed
Specifies whether to allow the allocation of additional physical partitions on the physical volume.
Sets the availability of the physical volume. If you set the availability to not active, logical input and output to the physical volume are stopped. You should make a physical volume not active when the physical volume is removed from operation. Access to physical volume data by the file system or the virtual memory manager is stopped, but you can continue to use the system management commands.
Copies the contents of a logical volume to a new or existing logical volume.
Copies the contents of SourceLogicalVolume to a new or existing DestinationLogicalVolume. The SourceLogicalVolume parameter can be a logical volume name or a logical volume id.
Specifies that the DestinationLogicalVolume exists and that a new logical volume should not be created. If the DestinationLogicalVolume is smaller than the SourceLogicalVolume, the extra logical partitions are not copied. When you use this flag, any data already in the DestinationLogicalVolume is destroyed.
The volume group where the new logical volume resides. If this is not specified, the new logical volume resides in the same volume group as the SourceLogicalVolume.
Increases the size of a logical volume by adding unallocated physical partitions from within the volume group.
Increases the number of logical partitions allocated to the LogicalVolume by allocating the number of additional logical partitions
The full path name of a file containing records specifying the exact physical partitions to allocate to the logical volume. Records are in the form: PVname:PPnum1[-PPnum2], where PVname is the physical volume name and PPnum is the physical partition number. Use one record for each physical partition or each range of consecutive physical partitions. Partitions are used in the order given in the MapFile. Used partitions are skipped.
Sets the maximum number of physical volumes for new allocation. The value should be between one and the total number of physical volumes in the volume group.
Displays the characteristics and status of the LogicalVolume or lists the logical volume allocation map for the physical partitions on the PhysicalVolume.
If no flags are specified, the following status is displayed:
Logical volume - Name of the logical volume. Logical volume names must be unique, system wide, and can range from 1 to 15 characters.
Volume group - Name of the volume group. Volume group names must be unique, system wide, and can range from 1 to 15 characters.
Logical volume identifier - Identifier of the logical volume.
Permission - Access permission; read-only or read-write.
Volume group state - State of the volume group. If the volume group is activated with the "varyonvg" command, the state is either active/complete (indicating all physical volumes are active) or active/partial (indicating all physical volumes are not active). If the volume group is not activated with the "varyonvg" command, the state is inactive.
Logical volume state - State of the logical volume. Opened/stale indicates the logical volume is open but contains physical partitions that are not current. Opened/syncd indicates the logical volume is open and synchronized. Closed indicates the logical volume has not been opened.
Type - Logical volume type.
Write verify - Write verify state of on or off.
Mirror write consistency - Mirror write consistency state of yes or no.
Max LPs - Maximum number of logical partitions the logical volume can hold.
PP size - Size of each physical partition.
Copies - Number of physical partitions created for each logical partition when allocating.
Schedule policy - Sequential or parallel scheduling policy.
LPs - Number of logical partitions currently in the logical volume.
PPs - Number of physical partitions currently in the logical volume.
Stale partitions - Number of physical partitions in the logical volume that are not current.
Bad blocks - Bad block relocation policy.
Inter-policy - Inter-physical allocation policy.
Allocation - Current state of allocation, either strict or non strict. A strict allocation states that no copies for a logical partition are allocated on the same physical volume. If the allocation does not follow the strict criteria, it is called non strict. A non strict allocation states that at least one occurrence of two physical partitions belong to the same logical partition.
Intra-policy - Intra-physical allocation policy.
In band - Percentage of physical partitions in the logical volume that were successfully allocated according to the intra-physical allocation policy. This is a measurement of correspondence between the original intra-physical allocation policy and the actual allocation.
Upper bound - Maximum number of physical volumes for allocation.
Relocatable - Indicates whether the partitions can be relocated if a reorganization of partition allocation takes place.
Mount point - File system mount point for the logical volume, if applicable.
Strict - Indicates whether the allocation policy is strict.
Label - Specifies the label field for the logical volume.
PV distribution - The distribution of the logical volume within the volume group. The physical volumes used, the number of logical partitions on each physical volume, and the number of physical partitions on each physical volume are shown.
"-l" - Lists the following fields for each physical volume in the logical volume:
"-m" - Lists the following fields for each logical partition:
Displays information about a physical volume within a volume group.
Physical volume - Name of the physical volume.
Volume group - Name of volume group. Volume group names must be unique system wide names and can be from 1 to 15 characters long.
PVstate - State of the physical volume. If the volume group that contains the physical volume is varied on with the "varyonvg" command, the state is active, missing, or removed. If the physical volume is varied off with the varyoffvg command, the state is varied off.
VGstate - State of the volume group. If the volume group is activated with the "varyonvg" command, the state is either active/complete (indicating all physical volumes are active) or active/partial (indicating some physical volumes are not active). If the volume group is not activated with the "varyonvg" command, the state is inactive.
Allocatable - Allocation permission for this physical volume.
Logical volumes - Number of logical volumes using the physical volume.
Stale PPs - Number of physical partitions on the physical volume that are not current.
VG descriptors - Number of volume group descriptors on the physical volume.
PP size - Size of physical partitions on the volume.
Total PPs - Total number of physical partitions on the physical volume.
Free PPs - Number of free physical partitions on the physical volume.
Used PPs - Number of used physical partitions on the physical volume.
Free distribution - Number of free partitions available in each intra-physical volume section.
Used distribution - Number of used partitions in each intra-physical volume section.
The "lsvg" command displays information about volume groups. If you use the VolumeGroup parameter, only the information for that volume group is displayed. If you do not use the VolumeGroup parameter, a list of the names of all defined volume groups is displayed.
Moves allocated physical partitions from one physical volume to one or more other physical volumes.
Moves only the physical partitions allocated to the LogicalVolume and located on the SourcePhysicalVolume.
The "mklv" command creates a new logical volume within the VolumeGroup. For example, all file systems must be on separate logical volumes.
The minimum number of logical partitions to allocate to the logical volume. The minimum value must be equal to or less than the maximum..
The number of physical partitions allocated for each logical partition. The value can be from 1 to 3; the default is 1. A value of 2 or 3 indicates a mirrored logical volume.
Sets the logical volume type. The default type is the "jfs "(or journaled file system) file system.
The maximum number of logical partitions that can be allocated to the logical volume. The default value is "512". The maximum must be greater than or equal to the minimum.
Increases the number of physical partitions per logical partition within the logical volume. A logical partition may have one physical partition per logical partition, which is know as a 1 copy or unmirrored logical volume, or it may have two or three physical partitions per logical partition, which is known as a mirrored logical volume.
The new number of copies in each logical partition in the Logical Volume.
Removes physical volumes from a volume group. When all physical volumes are removed from the volume group, the volume group is deleted.
The "rmlv" command removes a logical volume. The LogicalVolume parameter can be a logical volume name or logical volume ID. The logical volume first must be closed. For example, if the logical volume contains a file system, it must be unmounted. However, removing the logical volume does not notify the operating system that the file system residing on it have been destroyed. The command "rmfs" updates the "/etc/filesystems" file.
This command destroys all data in the specified logical volumes.
The "rmlvcopy" command deallocates copies from each logical partition in the LogicalVolume.
Specifies whether to ensure data consistency among mirrored copies of a logical volume during normal I/O processing.
The size of the stripe for a striped logical volume. Can be 4 KB,16 KB, 32 KB, 64 KB, 128 KB, 256K, 512K, 1M, 2M, 4M, 8M, 16M, 32M, 64M or 128M. This value is also known as stripe unit size. If no size is specified, the logical volume is assumed to be a non-striped logical volume.
Changing the name of an existing logical volume.
Specify the name of the logical volume to be changed.
Specify the new name of the logical volume.
Copies are the physical partitions which, in addition to the original physical partition, make up a logical partition. You can have up to two copies in a logical volume. The Copies parameter determines the maximum number of physical partitions.
Specifies how the destination for the logical volume copy is to be determined:
The name of the physical volume from which to move the contents.
If MAP files were created during a volume group backup, the default is to use those MAP files when remaking the volume group. Setting this field to NO remakes the logical volumes in the volume group without using the existing MAP files. MAP files allocate the same logical-to-physical partition mapping that was in the original volume group.
The number of megabytes in each physical partition, where the Size value is expressed in units of megabytes from 1 through 1024. The Size value must be equal to a power of 2 (example 1, 2, 4, 8). The default number of physical partitions per physical volume is 1016. Thus, a volume group that contains a physical volume larger than 4.064 gigabytes must have a physical partition size greater than 4 megabytes, or the volume group that contains this physical volume should have a factor value of more than 1, allowing 1016*factor number of partitions per physical volume.
If left blank, the value of the Physical partition SIZE in megabytes field is determined based on the sizes of the selected physical volumes.
Select from the list the paging spaces that you want to deactivate. The deactivated paging space will become unavailable for further paging space block allocation. After it is deactivated, you can remove it, either to reduce its size or to move it to some other logical volume on the volume group. You can perform this action without rebooting the system.
The number of logical partitions that will be removed to reduce paging space size.
Creates a big vg format volume group that can have up to 128 physical volumes and 512 logical volumes.
Changes the limit of the number of physical partitions per physical volume specified by factor. This value should be between 1 and 16 for 32-disk volume groups and 1 and 64 for 128-disk volume groups. When a value is specified, the maximum number of physical partitions per physical volume for this volume group changes to the factor value multiplied by 1016.
Sets the logical track group size, in number of kilobytes, of the volume group. The specified value must be 128, 256, 512, or 1024. It should also be less than or equal to the maximum transfer size of all disks in the volume group. The default size is 128 kilobytes.
Specify a path name, either relative or absolute, that you want to use as a substitute for vgname.data file.
This field is left blank by default. To use the vgname.data file stored in the backup image, leave this field blank.
Allows you to perform mirscan functions on a volume group. The mirscan command examines each allocated partition on the specified device and generates a report that lists whether the partition is stale or fresh, and lists whether the partition is capable of performing IO operations.
Allows you to perform mirscan functions on a logical volume. The mirscan command examines each allocated partition on the specified device and generates a report that lists whether the partition is stale or fresh, and lists whether the partition is capable of performing IO operations.
Allows you to perform mirscan functions on a physical volume. The mirscan command examines each allocated partition on the specified device and generates a report that lists whether the partition is stale or fresh, and lists whether the partition is capable of performing IO operations.
Specifies the volume group to be scanned.
Specifies which portions of the partition should be read. If you enter 0 in this field then only the first, middle, and last 512 bytes of each partition are read to determine whether the partition is capable of performing IO operations. If you enter a non-zero value such as 5, then only the first 5 512-byte blocks of each partition will be read to determine whether the partition is capable of performing IO operations.
Specifies an upperbound value that should override the natural upperbound value. The upperbound value should be between 1 and the total number of physical volumes in the volume group.
Specifies a strictness value that should override the natural strictness value. Legal values are Y, N, and S, where Y enables strictness, N disables strictness, and S enables superstrictness. By default, when mirscan has to perform a migration operation on a partition it will adhere to the natural strictness value of the logical volume that contains that partition.
Specifies the logical volume to be scanned.
Specifies a particular copy of the logical volume.
Specifies the physical volume to be scanned.