maximum size of a LV which we can create in LVM 2.x

[laiju.c.babu]

Hi Team,

Could  you please tell me any particular limitation is there for maximum size of a LV whichi we can create in LVM 2.x

 I knew  that in LV 1.0 max size of and LV will be 65535*PE  size

In one of our HPUX 11.31 server we had created  vg with version 1.0 . But now we need to extend a LV above 1Tb.   Because of the limitation of LM 1.0 we are not able to  do this.

So we are planning to change the vgversion to 2.x using the command and after that we are trying to extend the LV above 1 Tb.

Whether this plan will work ? Please provide your valid  suggetions on this.

Regards

[Torsten.]

The maximum size of a LVOL is

2TB in 11.11
16TB in 11.23 (patched ) and 11.31 with LVM 1,

256TB in 11.31 for LVM 2.

google
"HP-UX LVM Supported Limits"

[laiju.c.babu]

Hi Torsten,

But now in our server which we are using LVm 1.0 we are not able to increase the LV above 1Tb . The PE size which we are using there is 16MB

Regards

[Torsten.]

Yes, with this extends size 1TB is the limit (assuming you use a single PV).
extends size can be up to 256MB.

[Bill Hassell]

>> The PE size which we are using there is 16MB...

This PE Size is very small and therefore you cannot extend the lvol beyond 1TB.

You should use PE Size = 64 or 128.

However, you cannot change the PE Size on an existing VG. This requires creating a new VG and then moving all the data from the old VG to the new VG, or backup the existing data, then recreate the VG with the new PE Size.

This is a warning to alll sysadmins -- never use the default PE Size (4 MB) unless you know the VG will never be more than a few GB. Always specify a large PE Size (32, 64, 128 or 256) for any VG that will grow. At 11.31, the vgmodify command can adjust some of the VG limits but not PE Size.

[Torsten.]

LVM limits WP attached (this is a PDF, please rename it).

[laiju.c.babu]

Hi,
Thanks for the reply , Now i am using the vgversion 1.0 if i am changing the vg version to 2.2 then can i overcome this restriction.
My plan is
1)umount the current lv
2)deactivate the vg
3)use the command vgversion to change the version to 2.2
4)activate vg
5)mount lv
6)extend the lv above 2TB

Is this will work ?

[Torsten.]

probably yes, because a PV can have more extends in LVM 2.

[Robert_Jewell]

This command is useful in answering the original question:

# lvmadm -t

For example:

# lvmadm -t
--- LVM Limits ---
VG Version                  1.0
Max VG Size (Tbytes)        510
Max LV Size (Tbytes)        16
Max PV Size (Tbytes)        2
Max VGs                     256
Max LVs                     255
Max PVs                     255
Max Mirrors                 2
Max Stripes                 255
Max Stripe Size (Kbytes)    32768
Max LXs per LV              65535
Max PXs per PV              65535
Max Extent Size (Mbytes)    256

VG Version                  2.0
Max VG Size (Tbytes)        2048
Max LV Size (Tbytes)        256
Max PV Size (Tbytes)        16
Max VGs                     512
Max LVs                     511
Max PVs                     511
Max Mirrors                 5
Max Stripes                 511
Max Stripe Size (Kbytes)    262144
Max LXs per LV              33554432
Max PXs per PV              16777216
Max Extent Size (Mbytes)    256

VG Version                  2.1
Max VG Size (Tbytes)        2048
Max LV Size (Tbytes)        256
Max PV Size (Tbytes)        16
Max VGs                     2048
Max LVs                     2047
Max PVs                     2048
Max Mirrors                 5
Max Stripes                 511
Max Stripe Size (Kbytes)    262144
Max LXs per LV              33554432
Max PXs per PV              16777216
Max Extent Size (Mbytes)    256

VG Version                  2.2
Max VG Size (Tbytes)        2048
Max LV Size (Tbytes)        256
Max PV Size (Tbytes)        16
Max VGs                     2048
Max LVs                     2047
Max PVs                     2048
Max Mirrors                 5
Max Stripes                 511
Max Stripe Size (Kbytes)    262144
Max LXs per LV              33554432
Max PXs per PV              16777216
Max Extent Size (Mbytes)    256
Min Unshare unit(Kbytes)    512
Max Unshare unit(Kbytes)    4096
Max Snapshots per LV        255

-Bob