topic Re: Creating PVs in Operating System - HP-UX

Creating PVs

dasn — Thu, 24 May 2007 20:03:24 GMT

Hi Guys,
I have two LUNs mapped to my HP-UX host from Hitachi array connected in a fabric. Following is the ioscan output...

# ioscan -fnC disk
Class I H/W Path Driver S/W State H/W Type Description
=======================================================================
disk 1 0/0/1/1.15.0 sdisk CLAIMED DEVICE SEAGATE ST318404LC
/dev/dsk/c1t15d0 /dev/rdsk/c1t15d0
disk 5 0/2/0/0.2.0.255.0.0.0 sdisk CLAIMED DEVICE HITACHI DF500
/dev/dsk/c6t0d0 /dev/rdsk/c6t0d0
disk 12 0/2/0/0.2.0.255.0.0.1 sdisk CLAIMED DEVICE HITACHI DF500
/dev/dsk/c6t0d1 /dev/rdsk/c6t0d1
disk 17 0/4/0/0.1.0.255.0.0.0 sdisk CLAIMED DEVICE HITACHI DF500
/dev/dsk/c4t0d0 /dev/rdsk/c4t0d0
disk 18 0/4/0/0.1.0.255.0.0.1 sdisk CLAIMED DEVICE HITACHI DF500
/dev/dsk/c4t0d1 /dev/rdsk/c4t0d1
#

Both the LUNs are of 3 Gig size. I want to create one logical volumes of 3Gig size in each lun and also add pvlink into it. Would some one give me the steps ?

Also, previously i had created some volumes in one of these luns,

VG Name /dev/vg01
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 3
Open LV 3
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 1016
VGDA 2
PE Size (Mbytes) 4
Total PE 767
Alloc PE 750
Free PE 17
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0
How do i delete it and start a fresh ?

Thanks in advance for the reply.

Re: Creating PVs

freddy_21 — Thu, 24 May 2007 21:27:45 GMT

Hello,

could you give me vgdisplay -v vg01? because i dont know your disk already configure.

if you send the output. i will write step by step.

thank
freddy

Re: Creating PVs

dasn — Thu, 24 May 2007 21:31:31 GMT

Here is the output...

# vgdisplay -v vg01
--- Volume groups ---
VG Name /dev/vg01
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 3
Open LV 3
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 1016
VGDA 2
PE Size (Mbytes) 4
Total PE 767
Alloc PE 750
Free PE 17
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Logical volumes ---
LV Name /dev/vg01/pvlink_test_vol_01
LV Status available/syncd
LV Size (Mbytes) 1000
Current LE 250
Allocated PE 250
Used PV 1

LV Name /dev/vg01/pvlink_test_vol_02
LV Status available/syncd
LV Size (Mbytes) 2000
Current LE 500
Allocated PE 500
Used PV 1

LV Name /dev/vg01/pvlink_test_vol_03
LV Status available/syncd
LV Size (Mbytes) 0
Current LE 0
Allocated PE 0
Used PV 0

--- Physical volumes ---
PV Name /dev/dsk/c6t0d0
PV Name /dev/dsk/c4t0d0 Alternate Link
PV Status available
Total PE 767
Free PE 17
Autoswitch On

#

Thanks for the response

Re: Creating PVs

freddy_21 — Thu, 24 May 2007 21:43:27 GMT

c4t0d1 and c6t0d1 is one new disk ( alternate )

check with pvdisplay -v /dev/dsk/c6t0d1
have any lvol configuration? if no it means this is new disk.

the command are:
1. format new disk
#pvcreate -f /dev/rdsk/c6t0d1
2. extend new disk at vg01 configuration
vgextend /dev/vg01 /dev/dsk/c6t0d1 /dev/dsk/c4t0d1
3. please used sam for configure lvol. more easier because no need write fstab file or other.

thanks
freddy

Re: Creating PVs

dasn — Thu, 24 May 2007 21:48:46 GMT

Yes that is right. c4t0d1 and c6t0d1 is a new disk. I am sorry, actually i want to re-create LV using lun d0 only, which already have some LVs created which i want to delete and freshly create a sinlge volume using entire 3gig. I dont want to create any LVs in d1 lun. Thanks,
NKD

Re: Creating PVs

freddy_21 — Thu, 24 May 2007 21:59:11 GMT

Hello Dasn,

I still dont understand what do you need.

My understanding>

vg01 have 1 disk the size 3 GB with 3 logical volume. Now you have 1 new disk the size 3 GB. You want to cretae new volume group so the result:
vg01 only have 1 logical volume ( lvol size 3 GB ) <-- existing disk
vg02 only have 1 logical volume ( lvol size 3 GB ) <-- new disk

thanks
freddy

Re: Creating PVs

dasn — Thu, 24 May 2007 22:02:49 GMT

vg01 only have 1 logical volume ( lvol size 3 GB ) <-- existing disk

I want to the above opeartion only. I dont want to create any lvol in the new disk. I dont want to touch it. Hope its more clear now ?

Re: Creating PVs

freddy_21 — Thu, 24 May 2007 22:08:39 GMT

hello dasn

you must care about your data.
vg01 have 3 lvol but only 2 lvols have size.

LV Name /dev/vg01/pvlink_test_vol_01
LV Status available/syncd
LV Size (Mbytes) 1000
Current LE 250
Allocated PE 250
Used PV 1

LV Name /dev/vg01/pvlink_test_vol_02
LV Status available/syncd
LV Size (Mbytes) 2000
Current LE 500
Allocated PE 500
Used PV 1

LV Name /dev/vg01/pvlink_test_vol_03
LV Status available/syncd
LV Size (Mbytes) 0
Current LE 0
Allocated PE 0
Used PV 0

how about data at
/dev/vg01/pvlink_test_vol_01 <- 1 GB
/dev/vg01/pvlink_test_vol_02 <- 2 GB
/dev/vg01/pvlink_test_vol_03 <- 0 GB

are you ok with your data at both lvol?

Thanks
freddy

Re: Creating PVs

Denver Osborn — Thu, 24 May 2007 22:10:53 GMT

Ok, you have VG01 with one lun (c4t0d0) and 3 test lvols. you want to remove the 3 test lvols and create one lvol using all of c4t0d0. You don't want to touch the other lun c4t0d1. Is this right? If so, here's what you can do.

1) unmount the 3 test lvols if they are, then remove the lvols.

umount /dev/vg01/pvlink_test_vol_01
umount /dev/vg01/pvlink_test_vol_02
umount /dev/vg01/pvlink_test_vol_03

lvremove /dev/vg01/pvlink_test_vol_01
lvremove /dev/vg01/pvlink_test_vol_02
lvremove /dev/vg01/pvlink_test_vol_03

2) now that the test lvols are removed, create your new lvol.

lvcreate -n lvol_name -l 767 /dev/vg01

That's it. You can create the filesystem or do whatever you had planned for it.

If you intended on adding the new lun c4t0d1 to the volume group, you will need to pvcreate then vgextend to add c4t0d1 to vg01.

-denver

Re: Creating PVs

dasn — Thu, 24 May 2007 22:11:52 GMT

Yes very much. These are tests luns and does not contain any valuable data. I am doing some test with it.

Thanks for reply.

Re: Creating PVs

freddy_21 — Thu, 24 May 2007 22:15:04 GMT

i think denver way is right. Sorry i cant understand what you want. need more explanation. before make wrong with your data and configuration.

dont forget newfs for new lvol.

thanks
freddy

Re: Creating PVs

dasn — Thu, 24 May 2007 22:16:28 GMT

Denever,
Your understanding is right. Could you please explain the command,

lvcreate -n lvol_name -l 767 /dev/vg01 ? what it will do ?? Will it automatically calculate the size for the vol from /dev/vg01 or it would spread itself in the entire size ??

Thanks for the response.
- Niranjan

Re: Creating PVs

Denver Osborn — Thu, 24 May 2007 22:27:35 GMT

lvcreate -n lvol_name -l 767 /dev/vg01

"-n" so you can provide a non-default name for the volume.

"-l" is the number of extents to allocate to the lvol. Using 767 for this value tells LVM you'll use the entire disk for your lvol. As per the vgdisplay -v output, the disk has 767 extents (Total PE).

You could also use "-L" to specify the size of the lvol in MB. With 767 PE at 4MB, using "-L 3068" should also use all of the available space for the lvol.

-denver