Red Hat SummitEste conteúdo não está disponível no idioma selecionado.
5.9. Customized Reporting for LVM
You can produce concise and customizable reports of LVM objects with the
pvs, lvs, and vgs commands. The reports that these commands generate include one line of output for each object. Each line contains an ordered list of fields of properties related to the object. There are five ways to select the objects to be reported: by physical volume, volume group, logical volume, physical volume segment, and logical volume segment.
The following sections provide:
- A summary of command arguments you can use to control the format of the generated report.
- A list of the fields you can select for each LVM object.
- A summary of command arguments you can use to sort the generated report.
- Instructions for specifying the units of the report output.
5.9.1. Format Control
Copiar o linkLink copiado para a área de transferência!
Whether you use the
pvs, lvs, or vgs command determines the default set of fields displayed and the sort order. You can control the output of these commands with the following arguments:
- You can change what fields are displayed to something other than the default by using the
-oargument. For example, the following output is the default display for thepvscommand (which displays information about physcial volumes).Copy to Clipboard Copied! Toggle word wrap Toggle overflow The following command displays only the physical volume name and size.Copy to Clipboard Copied! Toggle word wrap Toggle overflow - You can append a field to the output with the plus sign (+), which is used in combination with the -o argument.The following example displays the UUID of the physical volume in addition to the default fields.
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Adding the
-vargument to a command includes some extra fields. For example, thepvs -vcommand will display theDevSizeandPV UUIDfields in addition to the default fields.Copy to Clipboard Copied! Toggle word wrap Toggle overflow - The
--noheadingsargument suppresses the headings line. This can be useful for writing scripts.The following example uses the--noheadingsargument in combination with thepv_nameargument, which will generate a list of all physical volumes.pvs --noheadings -o pv_name
# pvs --noheadings -o pv_name /dev/sdb1 /dev/sdc1 /dev/sdd1Copy to Clipboard Copied! Toggle word wrap Toggle overflow - The
--separator separatorargument uses separator to separate each field.The following example separates the default output fields of thepvscommand with an equals sign (=).Copy to Clipboard Copied! Toggle word wrap Toggle overflow To keep the fields aligned when using theseparatorargument, use theseparatorargument in conjunction with the--alignedargument.Copy to Clipboard Copied! Toggle word wrap Toggle overflow
You can use the
-P argument of the lvs or vgs command to display information about a failed volume that would otherwise not appear in the output. For information on the output this argument yields, see Section 7.2, “Displaying Information on Failed Devices”.
For a full listing of display arguments, see the
pvs(8), vgs(8) and lvs(8) man pages.
Volume group fields can be mixed with either physical volume (and physical volume segment) fields or with logical volume (and logical volume segment) fields, but physical volume and logical volume fields cannot be mixed. For example, the following command will display one line of output for each physical volume.
5.9.2. Object Selection
Copiar o linkLink copiado para a área de transferência!
This section provides a series of tables that list the information you can display about the LVM objects with the
pvs, vgs, and lvs commands.
For convenience, a field name prefix can be dropped if it matches the default for the command. For example, with the
pvs command, name means pv_name, but with the vgs command, name is interpreted as vg_name.
Executing the following command is the equivalent of executing
pvs -o pv_free.
The pvs Command
Copiar o linkLink copiado para a área de transferência!
Table 5.1, “pvs Display Fields” lists the display arguments of the
pvs command, along with the field name as it appears in the header display and a description of the field.
| Argument | Header | Description |
|---|---|---|
dev_size | DevSize | The size of the underlying device on which the physical volume was created |
pe_start | 1st PE | Offset to the start of the first physical extent in the underlying device |
pv_attr | Attr | Status of the physical volume: (a)llocatable or e(x)ported. |
pv_fmt | Fmt | The metadata format of the physical volume (lvm2 or lvm1) |
pv_free | PFree | The free space remaining on the physical volume |
pv_name | PV | The physical volume name |
pv_pe_alloc_count | Alloc | Number of used physical extents |
pv_pe_count | PE | Number of physical extents |
pvseg_size | SSize | The segment size of the physical volume |
pvseg_start | Start | The starting physical extent of the physical volume segment |
pv_size | PSize | The size of the physical volume |
pv_tags | PV Tags | LVM tags attached to the physical volume |
pv_used | Used | The amount of space currently used on the physical volume |
pv_uuid | PV UUID | The UUID of the physical volume |
The
pvs command displays the following fields by default: pv_name, vg_name, pv_fmt, pv_attr, pv_size, pv_free. The display is sorted by pv_name.
Using the
-v argument with the pvs command adds the following fields to the default display: dev_size, pv_uuid.
You can use the
--segments argument of the pvs command to display information about each physical volume segment. A segment is a group of extents. A segment view can be useful if you want to see whether your logical volume is fragmented.
The
pvs --segments command displays the following fields by default: pv_name, vg_name, pv_fmt, pv_attr, pv_size, pv_free, pvseg_start, pvseg_size. The display is sorted by pv_name and pvseg_size within the physical volume.
You can use the
pvs -a command to see devices detected by LVM that have not been initialized as LVM physical volumes.
The vgs Command
Copiar o linkLink copiado para a área de transferência!
Table 5.2, “vgs Display Fields” lists the display arguments of the
vgs command, along with the field name as it appears in the header display and a description of the field.
| Argument | Header | Description |
|---|---|---|
lv_count | #LV | The number of logical volumes the volume group contains |
max_lv | MaxLV | The maximum number of logical volumes allowed in the volume group (0 if unlimited) |
max_pv | MaxPV | The maximum number of physical volumes allowed in the volume group (0 if unlimited) |
pv_count | #PV | The number of physical volumes that define the volume group |
snap_count | #SN | The number of snapshots the volume group contains |
vg_attr | Attr | Status of the volume group: (w)riteable, (r)eadonly, resi(z)eable, e(x)ported, (p)artial and (c)lustered. |
vg_extent_count | #Ext | The number of physical extents in the volume group |
vg_extent_size | Ext | The size of the physical extents in the volume group |
vg_fmt | Fmt | The metadata format of the volume group (lvm2 or lvm1) |
vg_free | VFree | Size of the free space remaining in the volume group |
vg_free_count | Free | Number of free physical extents in the volume group |
vg_name | VG | The volume group name |
vg_seqno | Seq | Number representing the revision of the volume group |
vg_size | VSize | The size of the volume group |
vg_sysid | SYS ID | LVM1 System ID |
vg_tags | VG Tags | LVM tags attached to the volume group |
vg_uuid | VG UUID | The UUID of the volume group |
The
vgs command displays the following fields by default: vg_name, pv_count, lv_count, snap_count, vg_attr, vg_size, vg_free. The display is sorted by vg_name.
vgs
# vgs
VG #PV #LV #SN Attr VSize VFree
new_vg 3 1 1 wz--n- 51.42G 51.36G
Using the
-v argument with the vgs command adds the following fields to the default display: vg_extent_size, vg_uuid.
The lvs Command
Copiar o linkLink copiado para a área de transferência!
Table 5.3, “lvs Display Fields” lists the display arguments of the
lvs command, along with the field name as it appears in the header display and a description of the field.
| Argument | Header | Description | ||||||
|---|---|---|---|---|---|---|---|---|
| Chunk | Unit size in a snapshot volume | ||||||
copy_percent | Copy% | The synchronization percentage of a mirrored logical volume; also used when physical extents are being moved with the pv_move command | ||||||
devices | Devices | The underlying devices that make up the logical volume: the physical volumes, logical volumes, and start physical extents and logical extents | ||||||
lv_attr | Attr | The status of the logical volume. The logical volume attribute bits are as follows:
| ||||||
lv_kernel_major | KMaj | Actual major device number of the logical volume (-1 if inactive) | ||||||
lv_kernel_minor | KMIN | Actual minor device number of the logical volume (-1 if inactive) | ||||||
lv_major | Maj | The persistent major device number of the logical volume (-1 if not specified) | ||||||
lv_minor | Min | The persistent minor device number of the logical volume (-1 if not specified) | ||||||
lv_name | LV | The name of the logical volume | ||||||
lv_size | LSize | The size of the logical volume | ||||||
lv_tags | LV Tags | LVM tags attached to the logical volume | ||||||
lv_uuid | LV UUID | The UUID of the logical volume. | ||||||
mirror_log | Log | Device on which the mirror log resides | ||||||
modules | Modules | Corresponding kernel device-mapper target necessary to use this logical volume | ||||||
move_pv | Move | Source physical volume of a temporary logical volume created with the pvmove command | ||||||
origin | Origin | The origin device of a snapshot volume | ||||||
| Region | The unit size of a mirrored logical volume | ||||||
seg_count | #Seg | The number of segments in the logical volume | ||||||
seg_size | SSize | The size of the segments in the logical volume | ||||||
seg_start | Start | Offset of the segment in the logical volume | ||||||
seg_tags | Seg Tags | LVM tags attached to the segments of the logical volume | ||||||
segtype | Type | The segment type of a logical volume (for example: mirror, striped, linear) | ||||||
snap_percent | Snap% | Current percentage of a snapshot volume that is in use | ||||||
stripes | #Str | Number of stripes or mirrors in a logical volume | ||||||
| Stripe | Unit size of the stripe in a striped logical volume |
The
lvs command displays the following fields by default: lv_name, vg_name, lv_attr, lv_size, origin, snap_percent, move_pv, mirror_log, copy_percent, convert_lv. The default display is sorted by vg_name and lv_name within the volume group.
lvs
# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lvol0 new_vg owi-a- 52.00M
newvgsnap1 new_vg swi-a- 8.00M lvol0 0.20
Using the
-v argument with the lvs command adds the following fields to the default display: seg_count, lv_major, lv_minor, lv_kernel_major, lv_kernel_minor, lv_uuid.
You can use the
--segments argument of the lvs command to display information with default columns that emphasize the segment information. When you use the segments argument, the seg prefix is optional. The lvs --segments command displays the following fields by default: lv_name, vg_name, lv_attr, stripes, segtype, seg_size. The default display is sorted by vg_name, lv_name within the volume group, and seg_start within the logical volume. If the logical volumes were fragmented, the output from this command would show that.
Using the
-v argument with the lvs --segments command adds the following fields to the default display: seg_start, stripesize, chunksize.
The following example shows the default output of the
lvs command on a system with one logical volume configured, followed by the default output of the lvs command with the segments argument specified.
5.9.3. Sorting LVM Reports
Copiar o linkLink copiado para a área de transferência!
Normally the entire output of the
lvs, vgs, or pvs command has to be generated and stored internally before it can be sorted and columns aligned correctly. You can specify the --unbuffered argument to display unsorted output as soon as it is generated.
To specify an alternative ordered list of columns to sort on, use the
-O argument of any of the reporting commands. It is not necessary to include these fields within the output itself.
The following example shows the output of the
pvs command that displays the physical volume name, size, and free space.
The following example shows the same output, sorted by the free space field.
The following example shows that you do not need to display the field on which you are sorting.
To display a reverse sort, precede a field you specify after the
-O argument with the - character.
5.9.4. Specifying Units
Copiar o linkLink copiado para a área de transferência!
To specify the unit for the LVM report display, use the
--units argument of the report command. You can specify (b)ytes, (k)ilobytes, (m)egabytes, (g)igabytes, (t)erabytes, (e)xabytes, (p)etabytes, and (h)uman-readable. The default display is human-readable. You can override the default by setting the units parameter in the global section of the lvm.conf file.
The following example specifies the output of the
pvs command in megabytes rather than the default gigabytes.
By default, units are displayed in powers of 2 (multiples of 1024). You can specify that units be displayed in multiples of 1000 by capitalizing the unit specification (B, K, M, G, T, H).
The following command displays the output as a multiple of 1024, the default behavior.
The following command displays the output as a multiple of 1000.
You can also specify (s)ectors (defined as 512 bytes) or custom units.
The following example displays the output of the
pvs command as a number of sectors.
The following example displays the output of the
pvs command in units of 4 megabytes.
'%20d='M201.5%20305.5c-13.8%200-24.9-11.1-24.9-24.6%200-13.8%2011.1-24.9%2024.9-24.9%2013.6%200%2024.6%2011.1%2024.6%2024.9%200%2013.6-11.1%2024.6-24.6%2024.6zM504%20256c0%20137-111%20248-248%20248S8%20393%208%20256%20119%208%20256%208s248%20111%20248%20248zm-132.3-41.2c-9.4%200-17.7%203.9-23.8%2010-22.4-15.5-52.6-25.5-86.1-26.6l17.4-78.3%2055.4%2012.5c0%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.3%2024.9-24.9s-11.1-24.9-24.9-24.9c-9.7%200-18%205.8-22.1%2013.8l-61.2-13.6c-3-.8-6.1%201.4-6.9%204.4l-19.1%2086.4c-33.2%201.4-63.1%2011.3-85.5%2026.8-6.1-6.4-14.7-10.2-24.1-10.2-34.9%200-46.3%2046.9-14.4%2062.8-1.1%205-1.7%2010.2-1.7%2015.5%200%2052.6%2059.2%2095.2%20132%2095.2%2073.1%200%20132.3-42.6%20132.3-95.2%200-5.3-.6-10.8-1.9-15.8%2031.3-16%2019.8-62.5-14.9-62.5zM302.8%20331c-18.2%2018.2-76.1%2017.9-93.6%200-2.2-2.2-6.1-2.2-8.3%200-2.5%202.5-2.5%206.4%200%208.6%2022.8%2022.8%2087.3%2022.8%20110.2%200%202.5-2.2%202.5-6.1%200-8.6-2.2-2.2-6.1-2.2-8.3%200zm7.7-75c-13.6%200-24.6%2011.1-24.6%2024.9%200%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.1%2024.9-24.6%200-13.8-11-24.9-24.9-24.9z'/%3e%3c/svg%3e){kind=small}