topic Re: mirrored disk size in Operating System - HP-UX

mirrored disk size

andi_1 — Thu, 28 Mar 2002 20:30:05 GMT

Hi guys,

Suppose, I have the following information:

--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 8
Open LV 8
Max PV 16
Cur PV 1
Act PV 1
Max PE per PV 2500
VGDA 2
PE Size (Mbytes) 4
Total PE 1023
Alloc PE 1019
Free PE 4
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Physical volumes ---
PV Name /dev/dsk/c11t5d0
PV Status available
Total PE 1023
Free PE 4

Am I correct assuming that /dev/dsk/c11t5do belongs to vg00.

Also, given the above information how do I know how much is mirrored? What field should I look for?

Thank you.

Re: mirrored disk size

Clemens van Everdingen — Thu, 28 Mar 2002 20:32:48 GMT

Hi,

Correct, that disk belongs to vg00.
But as far as I can see there is only one disk, so meaning that vg00 is not mirrored at all.

C.

Re: mirrored disk size

andi_1 — Thu, 28 Mar 2002 20:34:15 GMT

Clemens,

Thank you for your reply. So, assuming there are two disks, it means vg00 was mirrored over two disks?

Thanks!

Re: mirrored disk size

Sandip Ghosh — Thu, 28 Mar 2002 20:35:09 GMT

Do lvdisplay -v /dev/vg00 |more
to see which disk is mirrored with whom.

Sandip

Re: mirrored disk size

andi_1 — Thu, 28 Mar 2002 20:36:33 GMT

Hi,

I cannot do lvdisplay. This is information coming from the customer server, which I don't have access to.

So, I have to figure out based on the information provided.

Re: mirrored disk size

Helen French — Thu, 28 Mar 2002 20:36:43 GMT

Hi,

1) Yes, The disk belongs to vg00. A better way to check this can be:

# pvdisplay -v /dev/dsk/cxtydz

2) Mirroring is done at the LV level not at the VG level. You have to check the 'lvdisplay -v' to findout the mirror status of the lV:

# lvdisplay -v /dev/vgxx/lvolx

HTH,
Shiju

Re: mirrored disk size

S.K. Chan — Thu, 28 Mar 2002 20:39:08 GMT

There are a few ways of determine if vg00 is mirrored. Take for instance if you got 2 disks in vg00 (you know this from vgdisplay -v vg00), to confirm if they are mirrored or not you can run ..

# lvlnboot -v

Doing ..

# lvdisplay -v /dev/vg00/lvolX | more

on each individual LVs in vg00 will give you details (if they are mirrored) how those LVs are distributed over which disk.

Re: mirrored disk size

Helen French — Thu, 28 Mar 2002 20:40:42 GMT

Hi Leon:

Just by seeing 2 disks in vg00 ( or in any VG) doesn't mean that the disks are mirrored.

If you are talking about software mirror with Mirror/UX, then you can see the information from 'lvdisplay' command. If you are using a disk array/hardware mirror, then you can check the array status.

HTH,
Shiju

Re: mirrored disk size

Clemens van Everdingen — Thu, 28 Mar 2002 20:40:46 GMT

Hi,

vgdisplay -v /dev/vg00 should show that the volume group contains one or more disks.
If more than one, you should do as lvdisplay to see if these are mirror's of each other.

C.

Re: mirrored disk size

Sandip Ghosh — Thu, 28 Mar 2002 20:47:49 GMT

First you ask your customer to do lvdisplay -v /dev/vg00/lv*|more to see what it is saying as Mirror Copies. If it says 1 , that means it is mirrored. If it is saying 0 that means it is not mirrored.

If you could see 1 then oyu can do with -v option to see which physical disks are there in the mirrored partition.

Sandip

Re: mirrored disk size

Patrick Wallek — Thu, 28 Mar 2002 21:00:04 GMT

With this particular VG00, there is no way it can be mirrored. There is only 1 disk in this VG.

The first things to look at are the CUR PV and the ACT PV. Both of these are 1 on this VG, so there is no other disk to mirror to.

Re: mirrored disk size

Michael Tully — Thu, 28 Mar 2002 21:06:55 GMT

Only other thing to add, and to echo Sanjay is that if there was a second disk, and you feel it should be there it would shown in the vgdisplay output as a mirrored disk as 'stale'