AIX

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------

For the mirror operation to work, the disks must have the same block size. I believe you can set the LUN's blobksize in the storage subsystem. It the storage subsystem report a different block size between the 2 disks, AIX connot override it. But the storage system can. 

Unfortunately, I personally do now know how to change this in the storage subsystem. 

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------

Hi Juan Jose

You cant add other new volumes to an Volume Group id the block size of the new one is not equal to existing disks.
That is a problem with new hard drives with 4KB block size when legacy and generally SAN disks use just 512B.
Unfortunatelly this is a fixed setting coming from the hardware and it is not possible to be changed. 

I suggest you to do an mksysb and restore it on a new disk (LUN from SAN) 

I don't know if alt_disk_copy could work for this, I understand the process is like to a mirrorvg and then a splitvg more than a backup/restore from a VG to another. So, it should need again add the new disk to VG first... (I don't pretty sure of this, you can try it) 

It is possible to virtualize a file from VIOS to server to be seen as a new hdisk which broke with the fixed disk block size masking a new 512B device... but I do not recommend this because of performance and access redundancy.

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------

Hi Juan Jose,

I advice you to read 

https://techchannel.com/SMB/06/2020/spare-disk-values-and-challenges

Hi Juan Jose

You cant add other new volumes to an Volume Group id the block size of the new one is not equal to existing disks.
That is a problem with new hard drives with 4KB block size when legacy and generally SAN disks use just 512B.
Unfortunatelly this is a fixed setting coming from the hardware and it is not possible to be changed. 

I suggest you to do an mksysb and restore it on a new disk (LUN from SAN) 

I don't know if alt_disk_copy could work for this, I understand the process is like to a mirrorvg and then a splitvg more than a backup/restore from a VG to another. So, it should need again add the new disk to VG first... (I don't pretty sure of this, you can try it) 

It is possible to virtualize a file from VIOS to server to be seen as a new hdisk which broke with the fixed disk block size masking a new 512B device... but I do not recommend this because of performance and access redundancy.

Hello everyone.

We want to mirror the rootvg on a SAN disk, but skip the next issue:

0516-1980 extendvg: Block size of all disks in the volume group must be the same. Cannot mix disks with different block sizes.

Is there any way to change the disk block zise on AIX disk (/dev/hdiskX) before to extend or add the new PV to the VG and get the mirror of the rootvg ?

Note: The disk where the OS resides is an internal NVMe disk.

Regards,

JJMO

------------------------------
Juan Jose Morales Ortiz
------------------------------