vgextend: Warning: Max_PE_per_PV for the volume group

[sapoguheman]

diskinfo /dev/rdisk/disk222
SCSI describe of /dev/rdisk/disk222:
             vendor: HITACHI
         product id: OPEN-V
               type: direct access
               size: 141557760 Kbytes
   bytes per sector: 512
:/>bc
141557760/1024/1024
135

Disk is 135 gb I have done pvcreate on this disk

I am trying to extend /dev/vg01 but i get error as below.

vgextend: Warning: Max_PE_per_PV for the volume group (8710) too small for this PV (34559).
         Using only 8710 PEs from this physical volume.

:/>vgdisplay vg01
--- Volume groups ---
VG Name                     /dev/vg01
VG Write Access             read/write
VG Status                   available
Max LV                      255
Cur LV                      16
Open LV                     16
Max PV                      16
Cur PV                      16
Act PV                      16
Max PE per PV               8710
VGDA                        32
PE Size (Mbytes)            4
Total PE                    139344
Alloc PE                    139098
Free PE                     246
Total PVG                   0
Total Spare PVs             0
Total Spare PVs in use      0
VG Version                  1.0
VG Max Size                 557440m
VG Max Extents              139360

[Dennis Handly]

Basically your "PE Size (Mbytes)    4" is too small.

Max PE per PV     8710 * 4 == 34840 MB.

And the mentioned 34559 * 4 is 138236 MB == 134 GB

[Matti_Kurkela]

Your Max PV is 16, so the maximum capacity of your current VG is 16 * 8710 * 4 == 557440 MB.

Some VG parameters can be changed with the "vgmodify" command, but the PE Size can only be set at VG creation time.

You're now hitting the limits of your current configuration: you've now reached the Max PV value, and the Max PE per PV value is stopping you from adding as big PVs as you would like. You cannot extend the current VG any further without changing the VG paramters.

You might want to create a completely new VG, using parameters that won't restrict expansion in the future, and then copy the data to it. Then you can remove the old VG and mount the new one in its place.

With "vgcreate -s 64 -e 32768" you can create a VG that can take PVs of up to 2 TB in size, which is the maximum allowed by LVM 1.0. Other such combinations are "vgcreate -s 128 -e 16384" and "vgcreate -s 256 -e 8192".

Increasing the PE Size (the -s parameter) will make LV sizing more granular, but the VG configuration backup files will be smaller. Since the VG configuration backup files go to the root filesystem, this might be important if you have huge amounts of data and a small root filesystem.

Going beyond the above values is overkill, because LVM 1.0 has a fundamental limit of 2 TB for PV size anyway.

(On modern systems, I would recommend always using one of the above combinations when creating new LVM 1.0 VGs for applications or data, unless you have specific reasons to do otherwise!)

Alternatively, if there is no need to access this VG from HP-UX versions older than 11.31 Release 03/2008, you can go to LVM 2.x with much higher limits and fewer technical restrictions.