Physical volume(PV) attributes:
To check the physical volume attributes,use “pvs” command.The forth column of pvs command output displays the physical volume attributes.
[root@mylinz ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 /dev/sdd1 uavg lvm2 a- 508.00m 408.00m /dev/sde uavg lvm2 a- 508.00m 508.00m /dev/sdf uavg lvm2 a- 5.00g 5.00g [root@mylinz ~]#
The above command output shows “a” in the attribute field which explains that physical volumes can be “allocated” to the volumes.
Export the volume group “uavg” and check pvs output.
[root@mylinz ~]# vgexport uavg Volume group "uavg" successfully exported [root@mylinz ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 /dev/sdd1 uavg lvm2 ax 508.00m 408.00m /dev/sde uavg lvm2 ax 508.00m 508.00m /dev/sdf uavg lvm2 ax 5.00g 5.00g [root@mylinz ~]#
In attributes field, you can see that “x” is added now.This show that volume group is exported.
We can stop the allocation to the disk by using pvchnage command.By disabling allocation,volume will not be extended using that specific physical volume.
[root@mylinz ~]# pvchange -x n /dev/sdd1 Physical volume "/dev/sdd1" changed 1 physical volume changed / 0 physical volumes not changed [root@mylinz ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 /dev/sdd1 uavg lvm2 -- 508.00m 408.00m /dev/sde uavg lvm2 a- 508.00m 508.00m /dev/sdf uavg lvm2 a- 5.00g 5.00g [root@mylinz ~]#
You can revert the change any time using below mentioned command.
[root@mylinz ~]# pvchange -x y /dev/sdd1 Physical volume "/dev/sdd1" changed 1 physical volume changed / 0 physical volumes not changed [root@mylinz ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 /dev/sdd1 uavg lvm2 a- 508.00m 408.00m /dev/sde uavg lvm2 a- 508.00m 508.00m /dev/sdf uavg lvm2 a- 5.00g 5.00g [root@mylinz ~]#
Some of the useful commands to get the details of physical volume.
1.To get the physical volumes with “UID” , use “-v” option.
Note:You can also use “pvs -vv” to get more detailed information.
[root@mylinz ~]# pvs -v Scanning for physical volume names PV VG Fmt Attr PSize PFree DevSize PV UUID /dev/sdd1 uavg lvm2 ax 508.00m 408.00m 511.98m tJ5YhP-VOZV-yfQ6-Uyye-WGT7-VLcl-7M3RMK /dev/sde uavg lvm2 ax 508.00m 508.00m 512.00m FadWLT-LjD8-v8VB-pboY-eZbK-vYpE-ZWq0i9 /dev/sdf uavg lvm2 ax 5.00g 5.00g 5.00g GbvgWh-l0w3-wCA6-umkD-zfsS-8yAZ-GeOSKF [root@mylinz ~]#
2.To get all the disks connected to the system ,use “pvs -a”
[root@mylinz ~]# pvs -a PV VG Fmt Attr PSize PFree /dev/root -- 0 0 /dev/sda1 -- 0 0 /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 /dev/sdb1 -- 0 0 /dev/sdc1 -- 0 0 /dev/sdd1 uavg lvm2 ax 508.00m 408.00m /dev/sde uavg lvm2 ax 508.00m 508.00m /dev/sdf uavg lvm2 ax 5.00g 5.00g /dev/sdg -- 0 0 /dev/vg_mylinz/lv_swap -- 0 0 [root@mylinz ~]#
/dev/sda1 is not part of LVM but you get the disk list in pvs command.
3.To get the segment wise output,use below command.
[root@mylinz ~]# pvs --segments PV VG Fmt Attr PSize PFree Start SSize /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 0 4234 /dev/sda2 vg_mylinz lvm2 a- 19.51g 0 4234 760 /dev/sdd1 uavg lvm2 ax 508.00m 408.00m 0 13 /dev/sdd1 uavg lvm2 ax 508.00m 408.00m 13 25 /dev/sdd1 uavg lvm2 ax 508.00m 408.00m 38 89 /dev/sde uavg lvm2 ax 508.00m 508.00m 0 127 /dev/sdf uavg lvm2 ax 5.00g 5.00g 0 1279 [root@mylinz ~]#
Volume Group(VG) Attributes:
table.tableizer-table { border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif font-size: 12px; } .tableizer-table td { padding: 4px; margin: 3px; border: 1px solid #ccc; } .tableizer-table th { background-color: #104E8B; color: #FFF; font-weight: bold; }
Attributes | Description |
---|---|
r,w | (r)ead & (w)rite permissions |
z | resi(z)eable |
x | e(x)ported |
p | (p)artial |
c,n,a,i | allocation policy (c)ontiguous, c(l)ing, (n)ormal, (a)nywhere, (i)nherited |
c | (c)luster |
Here we will see sample vgs command output.
[root@mylinz ~]# vgs VG #PV #LV #SN Attr VSize VFree uavg 3 1 0 wz--n- 5.99g 5.89g vg_mylinz 1 2 0 wz--n- 19.51g 0 [root@mylinz ~]# [root@mylinz ~]# vgs -v Finding all volume groups Finding volume group "uavg" Finding volume group "vg_mylinz" VG Attr Ext #PV #LV #SN VSize VFree VG UUID uavg wz--n- 4.00m 3 1 0 5.99g 5.89g c87FyZ-5DND-oQ3n-iTh1-Vb1f-nBML-vUBUE9 vg_mylinz wz--n- 4.00m 1 2 0 19.51g 0 dIgmLP-aoe3-anxY-WHYE-bBtX-u28M-WF6Ye5 [root@mylinz ~]#
There are some other volume group attributes which will be useful while creating the new volume group.
table.tableizer-table { border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif font-size: 12px; } .tableizer-table td { padding: 4px; margin: 3px; border: 1px solid #ccc; } .tableizer-table th { background-color: #104E8B; color: #FFF; font-weight: bold; }
Attributes | Description |
---|---|
-l | maximum logical volumes |
-p | maximum physical volumes |
-s | physical extent size (default is 4MB) |
-A | autobackup |
[root@mylinz ~]# vgcreate -l 512 -p 256 -s 32M -Ay newvg /dev/sdf Volume group "newvg" successfully created vgs newvg VG #PV #LV #SN Attr VSize VFree newvg 1 0 0 wz--n- 4.97g 4.97g [root@mylinz ~]#
You can see the newly set values in vgdisplay command output.
[root@mylinz ~]# vgdisplay -v newvg Using volume group(s) on command line Finding volume group "newvg" --- Volume group --- VG Name newvg System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 512 Cur LV 0 Open LV 0 Max PV 256 Cur PV 1 Act PV 1 VG Size 4.97 GiB PE Size 32.00 MiB Total PE 159 Alloc PE / Size 0 / 0 Free PE / Size 159 / 4.97 GiB VG UUID Ny4xsv-uJ49-sZr9-lvfq-Oa7n-l5mH-1bPBbp --- Physical volumes --- PV Name /dev/sdf PV UUID GbvgWh-l0w3-wCA6-umkD-zfsS-8yAZ-GeOSKF PV Status allocatable Total PE / Free PE 159 / 159 [root@mylinz ~]#
Logical Volume (LV) Attributes:
Knowing the logical volume attributes.
[root@mylinz ~]# lvs LV VG Attr LSize Origin Snap% Move Log Copy% Convert vol1 uavg -wi-ao 100.00m lv_root vg_mylinz -wi-ao 16.54g lv_swap vg_mylinz -wi-ao 2.97g [root@mylinz ~]#
The below tables covers the “lvs” command attributes. table.tableizer-table { border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif font-size: 12px; } .tableizer-table td { padding: 4px; margin: 3px; border: 1px solid #ccc; } .tableizer-table th { background-color: #104E8B; color: #FFF; font-weight: bold; }
Volume Type Attributes(First Field of Attr) | Description |
---|---|
m | (m)irrored |
M | (M)irrored without intial sync |
o | (o)rgin |
p | (p)vmove |
s | (s)napshot |
S | invalid (S)napshot |
v | (v)irtual |
i | mirror (i)mage |
l | mirror (I)mage without sync |
c | under (c)onstruction |
– | Simple Volume |
table.tableizer-table { border: 1px solid #CCC; font-family: Arial, Helvetica, sans-serif font-size: 12px; } .tableizer-table td { padding: 4px; margin: 3px; border: 1px solid #ccc; } .tableizer-table th { background-color: #104E8B; color: #FFF; font-weight: bold; }
Attributes (second to sixth Field of Attr) | Description |
---|---|
w,r (Second Feild) | Permissions ‘(r)’ead ‘(w)’rite |
c,I,n.a,I (Third Feild) | Allocation policy (c)ontiguous, c(l)ing, (n)ormal, (a)nywhere, (i)nherited |
m (Fourth Feild) | Fixed (m)inor |
a,s,I (Fifth Feild) | (a)ctive, (s)uspended, (I)nvalid snapshot,, |
S (Fifth Feild) | Invalid (S)uspended snapshot |
I (Fifth Feild) | Mapped device present with (i)nactive table |
d (Fifth Feild) | Mapped (d)evice present with-out tables |
o (sixth Feild) | device (o)pen (Volume is in active state or may be mounted ) |
Here we will see some of the useful “lvs” command options.
1.To display the logical volumes with underlying physical volumes use,
[root@mylinz ~]# lvs -a -o +devices LV VG Attr LSize Origin Snap% Move Log Copy% Convert Devices vol1 uavg -wi-ao 100.00m /dev/sdd1(13) lv_root vg_mylinz -wi-ao 16.54g /dev/sda2(0) lv_swap vg_mylinz -wi-ao 2.97g /dev/sda2(4234) [root@mylinz ~]#
2.To see the complete physical disks segmnets for logical volumes,
[root@mylinz ~]# lvs -a -o +seg_pe_ranges --segments LV VG Attr #Str Type SSize PE Ranges vol1 uavg -wi-ao 1 linear 100.00m /dev/sdd1:13-37 lv_root vg_mylinz -wi-ao 1 linear 16.54g /dev/sda2:0-4233 lv_swap vg_mylinz -wi-ao 1 linear 2.97g /dev/sda2:4234-4993 [root@mylinz ~]#
3.For detailed logical volume information,
[root@mylinz ~]# lvdisplay --maps /dev/uavg/vol1 --- Logical volume --- LV Name /dev/uavg/vol1 VG Name uavg LV UUID XjMpRC-6f5k-FN9L-jz5v-f0Gj-wBpf-xc9GVD LV Write Access read/write LV Status available # open 1 LV Size 100.00 MiB Current LE 25 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:2 --- Segments --- Logical extent 0 to 24: Type linear Physical volume /dev/sdd1 Physical extents 13 to 37 [root@mylinz ~]#
Hope this post is informative for you.Thank you for reading this article.Please leave a comment if you have any doubt.I will get back to you.
Oflameo says
What happened the the physical volume “m” attribute?