topic Re: LV greater than 2TB in Operating System - HP-UX

LV greater than 2TB

Srinikalyan — Wed, 12 Aug 2009 12:59:55 GMT

Hi,

HP-UX 11iv2
Online JFS

I am able to create a logical volume of size greater than 2TB if my PE Size is 256. Is it possible to create LV of 2TB if PE size is 32? If not what's the reason?
--- Volume groups ---
VG Name /dev/vg_ex
VG Write Access read/write
VG Status available, exclusive
Max LV 255
Cur LV 12
Open LV 12
Max PV 255
Cur PV 93
Act PV 93
Max PE per PV 1016
VGDA 186
PE Size (Mbytes) 256
Total PE 75423
Alloc PE 75423
Free PE 0
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

LV Name /dev/vg_ex/lv1
LV Status available/syncd
LV Size (Mbytes) 5273600
Current LE 20600
Allocated PE 20600
Used PV 27

Thanks in advance,
Srini

Re: LV greater than 2TB

Stephan. — Wed, 12 Aug 2009 13:07:03 GMT

Please check http://docs.hp.com/en/6054/LVM_Limits_White_Paper_V4.pdf

for the relations inside lvm.

hth

Re: LV greater than 2TB

Srinikalyan — Wed, 12 Aug 2009 13:15:48 GMT

I can't find the required information from the document. I need to know Is it possible to create LV of 2TB if PE size is 32?

Re: LV greater than 2TB

Torsten. — Wed, 12 Aug 2009 13:20:38 GMT

"I can't find the required information from the document"

So you need to read it again (page 3).

Max size of a LV with 11.23 without several patches: 2TB, with patches 16TB.

Max LV size with LVM2.1 and 11.31 is 257TB.

Re: LV greater than 2TB

Steven E. Protter — Wed, 12 Aug 2009 13:22:58 GMT

Shalom,

Max PV 255

Your volume group is configured to default.

vgexport it, create it again, set -p 10 or some reasonable number.

You will need to do this to get enough PE's to allocate after you finish patching.

This post does not contradict what is posted above. It is complementary.

SEP

Re: LV greater than 2TB

James R. Ferguson — Wed, 12 Aug 2009 13:24:47 GMT

Hi:

> Is it possible to create LV of 2TB if PE size is 32?

If my math is correct, not quite. Given:

2*1099511627776/32768000

...or 2TB/32MB PE size ~ 67108 extents

...which exceeds the maxiumum number of extents for an LVM version-1 of 65535.

Regards!

...JRF...

Re: LV greater than 2TB

Roopesh Francis_1 — Wed, 12 Aug 2009 13:26:28 GMT

65,535 is maximum numbers of LE in a volume group. if your PE size is 32 ,the maximum size of a LV will be
65535*32=1.999GB

Thanks,

Re: LV greater than 2TB

Roopesh Francis_1 — Wed, 12 Aug 2009 13:26:48 GMT

65,535 is maximum number of LE in a volume group. if your PE size is 32 ,the maximum size of a LV will be
65535*32=1.999GB

Thanks,

Re: LV greater than 2TB

Srinikalyan — Thu, 13 Aug 2009 08:40:30 GMT

Thanks everyone.
Roopesh,
If my PE size is 64Mb, am I able to create LV of 64*65535= 4TB.

Re: LV greater than 2TB

Roopesh Francis_1 — Thu, 13 Aug 2009 11:03:05 GMT

you may create upto 16TB Size of a LV in 11.23 with the following or superseding patches:-
PHCO_36744, PHKL_36745, PHCO_37939.
please check above link which provided by svo
http://docs.hp.com/en/6054/LVM_Limits_White_Paper_V4.pdf

Re: LV greater than 2TB

Srinikalyan — Thu, 13 Aug 2009 13:16:37 GMT

Yes Roopesh.
We have installed those patches for creating the LV till 16TB. I think eventhough we have these patches installed, for creating the file system of greater than 2TB we should have Online JFS.
My question arose when we tried to create the LV of size 5TB in another system with both these items installed. LV creation was not successful because of PE size 32MB.

Re: LV greater than 2TB

James R. Ferguson — Thu, 13 Aug 2009 13:20:41 GMT

Hi Srini:

> I think even though we have these patches installed, for creating the file system of greater than 2TB we should have Online JFS.

The limitations are described here:

http://docs.hp.com/en/5971-2383/5971-2383.pdf

Regards!

...JRF...