size disk new to VG

[Eli Daniel]

good afternoon, I have a question:

now I have a vg with two 50 GB disk each. I need to add a new disk to vg. The new disk must be the same size of the other disk (50GB) or I can add a disk smaller or larger??
it affects?

Operation System HP-UX 11.23 64 bits

[John Guster · Accepted solution]

you need check with vgdisplay -v vgXX to see Max PE per PV value, if it is limited to 50GB per PV, then you only can have max size of 50GB disk to be added; if you add a disk with size > 50GB, only 50 GB will be usable.
you can add disks smaller size than 50 GB. the number of disks to be added is limited by "Max PV" in the vgdisplay output. Good luck.

[Eli Daniel]

example:

vgQAECC:

Max PE per PV 43521
the disk assigned 55 GB

i cant add 1 disk 80 GB???

[Eli Daniel]

i dont understand
"Max PE limited to 50GB per PV"

[Raj D.]

Daniel,

>I can add a disk smaller or larger??
>it affects?

- Yes, you can add any size of disk, smaller or larger than 50GB (smaller no problem, larger is limited to ( PE_Size * Max_PE_per_PV) value.





>vgQAECC:
>Max PE per PV 43521
# it will support #2720 PV size. with 64MB PE.


-in your case, Max PE per PV is 43521
check PE size as well:
# vgdisplay vgQAECC | grep "PE Size"

- if your PE size is 64, you can add a large disk , theoretically maximum 2720 GB.
Practically/usually the storage assigns lun size max 500GB or 1 TB, so in that case if you are planning to extend the VG with more than 50GB disk, you should be good.



Cheers,
Raj.

[Raj D.]

Daniel,

>i cant add 1 disk 80 GB???

Yes, you can add 80GB disk.
Even smallest PE size VG will allow to add max 170GB disks.

43521*4
174084


Cheers,
Raj.

[Raj D.]

Further Please post: #vgdisplay vgQAECC

[Eli Daniel]

SAPL905:/> vgdisplay vgQAECC | grep "PE Size"
PE Size (Mbytes) 4

[atul2701]

Raj smallest PE size for VG is 1Mb not 4Mb. 4 MB is the default size.
Atul

[Eli Daniel]

with PV 4 MB, I can add a 80GB disk??

[R.O.]

"with PV 4 MB, I can add a 80GB disk??"

Yes, you can. You can add a disk up to 170Gb.

Regards,

[Eli Daniel]

sorry for the question: because can add 1 disk 170 GB when PV = 4 MB???

[Raj D.]

Yes, Daniel.
> when PV = 4 MB???

Correction: not PV, when PE Size = 4 MB.

Cheers,
Raj.

[Raj D.]

Daniel,
Have a look at this document, things will be pretty clear :

1. HP-UX LVM Supported Limits. Whitepaper.
( Attached. 119KB)

Enjoy, Have fun!,
Raj.

[Eli Daniel]

Thanks