Pvmove is online

[rescuehp17]

Can pvmove be done online?

Planning to move the data from no. of disks to single disk.

[Torsten.]

It can be used online (except the VG is shared - see man page), but it can get tricky.

I prefer a mirror/unmirror procedure.

[rescuehp17]

Below steps sounds ok:

# pvcreate /dev/rdisk/disknew ==> new disk

# vgextend vgname /dev/disk/disknew

# lvextend -L 74120 /dev/vgname/lvname ==> double the disk space of lvm

# lvextend -m 1 /dev/vgname/lvname ==> mirror

# lvreduce -m 0 /dev/vgname/lvname /dev/disk/diskold

[rescuehp17]

But the above steps performed and got the following:

PV Name LE on PV PE on PV
/dev/disk/disk34 10 10
/dev/disk/disk35 10 10
/dev/disk/disk36 10 10
/dev/disk/disk37 10 10
/dev/disk/disk38 10 10
/dev/disk/disk39 9 9
/dev/disk/disk40 9 9
/dev/disk/disk41 9 9
/dev/disk/disk42 9 9
/dev/disk/disk43 9 9
/dev/disk/disk131 1641 1641
/dev/disk/disk136 581 581

disk131 and disk136 are new, so I thought when I mirrored and then removed disk34-43, still not removed. Goal to is move all the lvm data from 10 disks to new disks disk131 and disk136. Help is appreciated.

[Torsten.]

the lvextend -L step is wrong, don't do this.

[RogerVI]

if you have a mirror license, then use lvextend and lvreduce. In other case, use pvmove.

But if the destination is only one disk, then pvpaths must be indicated in lvextend. Same for lvreduce.

Example:

lvextend -m 1 /dev/vgxx/lvolxxx /dev/disk/diskx  /dev/disk/disky ...

[rescuehp17]

@Torsten., if I don't use lvextend -L, how can I extend the space for that logical volume? Since there are 2 other lvms in that VG...

# pvcreate /dev/rdisk/disknew ==> new disk

# vgextend vgname /dev/disk/disknew

# lvextend -L 74120 /dev/vgname/lvname ==> double the disk space of lvm ==== ignore this step and proceed next??

# lvextend -m 1 /dev/vgname/lvname ==> mirror

# lvreduce -m 0 /dev/vgname/lvname /dev/disk/diskold

[rescuehp17]

@RogerVI, so should do the following steps?

# pvcreate /dev/rdisk/disknew ==> new disk

# vgextend vgname /dev/disk/disknew

# lvextend -L 74120 /dev/vgname/lvname 

# lvextend -m 1 /dev/vgname/lvname /dev/disk/disknew /dev/disk/disknew1 ==> mirror

# lvreduce -m 0 /dev/vgname/lvname /dev/disk/diskold /dev/disk/diskold1 ==> removing old disks

Please suggest

[Torsten.]

For mirroring you need empty space inside the VG.

If you extend the LVOL size, there is no more space for mirroring.

So don't do this step.

With

# lvextend -m 1 /dev/vgname/lvname ==> mirror

you specify which LVOL to mirror to which disk.

To handle a large number of disks, you should use lvmpvg - with this group definition you specify to mirror from group of disks 1 to the other group (even if one group has only a single disk) -- many to one).

[Torsten.]

In order to mirror an lvol that resides on several disks (disk1..disk4 in this example) you create a physical volume group
definition like this:

create a text file
/etc/lvmpvg
with this contents:
VG   /dev/vg01
PVG  PVG0
/dev/disk/disk1
/dev/disk/disk2
/dev/disk/disk3
/dev/disk/disk4
PVG  PVG1
/dev/disk/disk5



Before mirroring a LV you need to set it’s allocation policy to PVG-strict, e.g:
# lvchange -s g /dev/vg01/lvol1

/usr/sbin/lvextend [-A autobackup] {-l le_number | -L lv_size | -m mirror_copies} lv_path [pv_path ... | pvg_name ...]

Then you create the physical volume, extend the VG and finally mirror the LVOL:


# pvcreate /dev/rdisk/disk5
# vgextend vg01 /dev/disk/disk5
# lvextend -m 1 /dev/vg01/lvol1 PVG1

[rescuehp17]

Thank you so much, Torsten.

How to create the PVG1? This got confused me.

# pvcreate /dev/rdisk/disk5
# vgextend vg01 /dev/disk/disk5
# lvextend -m 1 /dev/vg01/lvol1 PVG1

[Torsten.]

Please read my previous post again, I added a line for clarification

[rescuehp17]

Thank you and steps completed until mirroring part. how to remove the old disks?

[rescuehp17]

Mirroring:

# lvextend -m 1 /dev/vgother/lvoracle pvg2

After mirroring, to remove old disks:

# lvreduce -m 0 /dev/vgname/lvname pvg1

Correct?

[rescuehp17]

@/root> lvreduce -m 0 /dev/vgoracle/lvoracle pvg1 ==> this didn't work

@/root> for i in 33 34 35 36 37 38 39 40 41 42 43; do lvreduce -m 0 /dev/vgoracle/lvoracle /dev/disk/disk$i; done
Logical volume "/dev/vgoracle/lvoracle" has been successfully reduced.
Volume Group configuration for /dev/vgoracle has been saved in /etc/lvmconf/vgoracle.conf
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
lvreduce: "MirrorCopies" parameter "0" is not smaller than existing number "0";
therefore no mirrors are removed.
@/root> lvdisplay -v /dev/vgoracle/lvoracle|more
--- Logical volumes ---
LV Name /dev/vgoracle/lvoracle
VG Name /dev/vgoracle
LV Permission read/write
LV Status available/syncd
Mirror copies 0
Consistency Recovery MWC
Schedule parallel
LV Size (Mbytes) 20416
Current LE 638
Allocated PE 638
Stripes 0
Stripe Size (Kbytes) 0
Bad block on
Allocation PVG-strict
IO Timeout (Seconds) default

--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/disk/disk34 58 58
/dev/disk/disk35 58 58
/dev/disk/disk36 58 58
/dev/disk/disk37 58 58
/dev/disk/disk38 58 58
/dev/disk/disk39 58 58
/dev/disk/disk40 58 58
/dev/disk/disk41 58 58
/dev/disk/disk42 58 58
/dev/disk/disk43 58 58
/dev/disk/disk140 58 58

--- Logical extents ---
LE PV1 PE1 Status 1
00000 /dev/disk/disk140 00000 current
00001 /dev/disk/disk34 00178 current
00002 /dev/disk/disk35 00178 current
00003 /dev/disk/disk36 00178 current
00004 /dev/disk/disk37 00178 current
00005 /dev/disk/disk38 00178 current
00006 /dev/disk/disk39 00178 current
00007 /dev/disk/disk40 00178 current
00008 /dev/disk/disk41 00178 current
00009 /dev/disk/disk42 00178 current
00010 /dev/disk/disk43 00178 current
00011 /dev/disk/disk140 00011 current
00012 /dev/disk/disk34 00179 current
00013 /dev/disk/disk35 00179 current
00014 /dev/disk/disk36 00179 current
00015 /dev/disk/disk37 00179 current
00016 /dev/disk/disk38 00179 current
00017 /dev/disk/disk39 00179 current
00018 /dev/disk/disk40 00179 current
00019 /dev/disk/disk41 00179 current
00020 /dev/disk/disk42 00179 current
00021 /dev/disk/disk43 00179 current
00022 /dev/disk/disk140 00022 current
00023 /dev/disk/disk34 00180 current
00024 /dev/disk/disk35 00180 current
@/root> lvextend -m 1 /dev/vgoracle/lvoracle pvg2
LVM: Unable to map all the LEs to unique PEs.
lvextend: The LVM device driver could not extend the
logical volume "/dev/vgoracle/lvoracle".
@/root>

Goal is, to move everything to disk140

[Torsten.]

did you extend the lvol size???

there is data on the new disk, but no mirror at all!

[rescuehp17]

Fixed that issue. Turned off the PVG-strict and that worked.

But now, how to remove the disks33 to disk43? Want all the data only on one disk, which is disk140

--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/disk/disk33 163 163
/dev/disk/disk34 144 153
/dev/disk/disk35 145 153
/dev/disk/disk36 144 153
/dev/disk/disk37 145 153
/dev/disk/disk38 144 153
/dev/disk/disk39 58 58
/dev/disk/disk40 58 58
/dev/disk/disk41 58 58
/dev/disk/disk42 58 58
/dev/disk/disk43 58 58
/dev/disk/disk140 58 58

[Torsten.]

>> Turned off the PVG-strict and that worked.

What worked?

Not sure what exactly you did now.

How about a lvdisplay -v ...now?

And first lines of a pvdisplay -v ... too, please.

[rescuehp17]

Was able to mirror once I turn on the pvg-strict

[Torsten.]

pvg-strict means the original is in group1, mirror copy in group2.
without the mirror copy is anywhere in free space ... not on the disk you want!

depending on your settings the copy may be on the same disk - kind of useless.

[rescuehp17]

But it worked for me and migrated to the one disk.

[Torsten.]

How about some more current information about the status now, like

# vgdisplay -v vgoracle

# lvdisplay -v /dev/vgoracle/lvoracle

etc ... (see above).