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Hi,
I am facing problem while creating a Logical Volume
on a Multipath Lun.
There are 4 paths to a LUN. The corresponding scsi
devices are /dev/sdg, /dev/sdu, /dev/sdba, /dev/sdbj.
1. Initially there were no PVs, VGs and
LVs.
[root@PC-P31211 root]# pvscan
pvscan -- reading all physical volumes (this may take a while...) pvscan -- ERROR "pv_read(): read" reading physical volumes [root@PC-P31211 root]# vgscan vgscan -- reading all physical volumes (this may take a while...) vgscan -- "/etc/lvmtab" and "/etc/lvmtab.d" successfully created vgscan -- WARNING: This program does not do a VGDA backup of your volume group [root@PC-P31211 root]# lvscan lvscan -- no volume groups found 2. Then I created a PV on /dev/sdg1. (I had already
created partitions of sdg)
[root@PC-P31211 root]# pvcreate
/dev/sdg1
pvcreate -- physical volume "/dev/sdg1" successfully created The o/p of pvscan is as follows,
[root@PC-P31211 root]# pvscan
pvscan -- reading all physical volumes (this may take a while...) pvscan -- inactive PV "/dev/sdg1" is in no VG [402.61 MB] pvscan -- inactive PV "/dev/sdu1" is in no VG [402.61 MB] pvscan -- inactive PV "/dev/sdba1" is in no VG [402.61 MB] pvscan -- inactive PV "/dev/sdbj1" is in no VG [402.61 MB] pvscan -- total: 4 [1.57 GB] / in use: 0 [0] / in no VG: 4 [1.57 GB] Here u can notice that even though I have created
PV on sdg, pvscan shows all the scsi devices which are pointing to the same
LUN.
3. Then I created a VG on PV /dev/sdg1
[root@PC-P31211 root]# vgcreate test_vg
/dev/sdg1
vgcreate -- INFO: using default physical extent size 4 MB vgcreate -- INFO: maximum logical volume size is 255.99 Gigabyte vgcreate -- doing automatic backup of volume group "test_vg" vgcreate -- volume group "test_vg" successfully created and activated The o/p of vgscan & pvscan is as follows, [root@PC-P31211 root]# vgscan
vgscan -- reading all physical volumes (this may take a while...) vgscan -- found active volume group "test_vg" vgscan -- "/etc/lvmtab" and "/etc/lvmtab.d" successfully created vgscan -- WARNING: This program does not do a VGDA backup of your volume group [root@PC-P31211 root]# pvscan pvscan -- reading all physical volumes (this may take a while...) pvscan -- ACTIVE PV "/dev/sdg1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- inactive PV "/dev/sdu1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- inactive PV "/dev/sdba1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- inactive PV "/dev/sdbj1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- total: 4 [1.57 GB] / in use: 4 [1.57 GB] / in no VG: 0 [0] 4. Then I tried to create LV on "test_vg". But that
gave me error.
[root@PC-P31211 root]# lvcreate -L 50 -n
test_lv test_vg
lvcreate -- rounding size up to physical extent boundary lvcreate -- ERROR "No such device or address" creating VGDA for "/dev/test_vg/te st_lv" in kernel Also see the results of lvscan & lvdisplay
which are contradictory.
[root@PC-P31211 root]# lvscan
lvscan -- ACTIVE "/dev/test_vg/test_lv" [52 MB] lvscan -- 1 logical volumes with 52 MB total in 1 volume group lvscan -- 1 active logical volumes [root@PC-P31211 root]# lvdisplay /dev/test_vg/test_lv lvdisplay -- logical volume "/dev/test_vg/test_lv" doesn't exist Can any body help me to solve this
problem???
Somebody suggested me a solution...
a. Deactivate VG
b. Run vgscan
c. Activate VG
d. Create LV.
I followed these step. The o/p is given
below.
[root@PC-P31211 root]# vgchange -an
vgchange -- volume group "test_vg" successfully deactivated [root@PC-P31211 root]# vgscan vgscan -- reading all physical volumes (this may take a while...) vgscan -- found inactive volume group "test_vg" vgscan -- "/etc/lvmtab" and "/etc/lvmtab.d" successfully created vgscan -- WARNING: This program does not do a VGDA backup of your volume group [root@PC-P31211 root]# vgchange -ay vgchange -- volume group "test_vg" successfully activated [root@PC-P31211 root]# pvscan pvscan -- reading all physical volumes (this may take a while...) pvscan -- inactive PV "/dev/sdg1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- inactive PV "/dev/sdu1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- inactive PV "/dev/sdba1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- ACTIVE PV "/dev/sdbj1" of VG "test_vg" [396 MB / 396 MB free] pvscan -- total: 4 [1.57 GB] / in use: 4 [1.57 GB] / in no VG: 0 [0] [root@PC-P31211 root]# lvcreate -L 50 -n test_lv test_vg lvcreate -- rounding size up to physical extent boundary lvcreate -- doing automatic backup of "test_vg" lvcreate -- logical volume "/dev/test_vg/test_lv" successfully created [root@PC-P31211 root]# lvscan lvscan -- ACTIVE "/dev/test_vg/test_lv" [52 MB] lvscan -- 1 logical volumes with 52 MB total in 1 volume group lvscan -- 1 active logical volumes [root@PC-P31211 root]# lvdisplay /dev/test_vg/test_lv --- Logical volume --- LV Name /dev/test_vg/test_lv VG Name test_vg LV Write Access read/write LV Status available LV # 1 # open 0 LV Size 52 MB Current LE 13 Allocated LE 13 Allocation next free Read ahead sectors 120 Block device 58:0 This apporach helped me to create the Logical
Volume. But it does not fulfill my requirement. Here initially I had
created VG on sdg1, but after doing (vgchange -an, vgscan, vgchage -ay) that VG
got shifted on sdbj. And hence LV will also be created on this LV. But I want LV
to be created on sdj only. Is there any solution to my problem???
Regards,
Sameer Halgatti |
