topic Re: Mirror Question in Operating System - HP-UX

Mirror Question

Dwayne De Salvo — Tue, 07 Mar 2006 12:39:53 GMT

Is it normal for a mirror disk to display the byte size for both disks that are mirrored?

Re: Mirror Question

TwoProc — Tue, 07 Mar 2006 12:41:48 GMT

Show us the output of what you mean.

Re: Mirror Question

Steven E. Protter — Tue, 07 Mar 2006 12:46:30 GMT

Shalom Dwayne,

The logical volume that is mirrored will appear to the system as one disk. A pvdisplay on either disk should show the same output with regards to the logical volume that was mirrored.

In general with HP-UX you don't mirror a whole disk, you mirror logical volumes, so I think the answer to your question is no.

SEP
HP meayaim oty?

Re: Mirror Question

Dwayne De Salvo — Tue, 07 Mar 2006 12:55:02 GMT

View General Information for Volume Group: vg00
Volume Group Name: vg00 Activation Mode: Read/Write
Maximum Capacity (mbytes): 556800
Current Capacity (mbytes): 69440 Megabytes Used: 33560
Megabytes Free: 35880
Max. No. of Logical Volumes: 255
Cur. No. of Logical Volumes: 9
Disk Capacity Limit (mbytes): 34800
Maximum Number of Disks: 16
Current Number of Disks: 2
Hot Spares Configured: 0

Re: Mirror Question

Jeff Schussele — Tue, 07 Mar 2006 12:56:51 GMT

Not sure what you mean by "byte size".
It's always been 8 bits in my book %~))
BUT - as long as the mirroring disk is >= to the original disk in size, you're fine.
Use the diskinfo command to see the raw disk size.
And no, the "normal" commands - lvdisplay, vgdisplay & pvdisplay will not show the size, per se. They will show PE size & PE counts which can be implied.

My $0.02,
Jeff

Re: Mirror Question

TwoProc — Tue, 07 Mar 2006 13:04:08 GMT

OK, your output shows the data for the whole volume group, not a mirrored disk (which in your case is probably part of the volume group shown).

So, yes, the answer to your question (if I may restate it) - it would display the total byte size for all of the disks in the volume group, including the mirrored ones.

The below for clarification:

Keep in mind that "disks" (actual spinning disks) are put together into volume groups. Volume groups are cut up into lvols (logical volumes) which can be mirrored across the disks that belong in the volume group.

diska (see this info with "pvdisplay" )
diskb

make up volume 00 (vg00)
(see the above info with "vgdisplay")

which is cut up into:
lvol1
lvol2 (see each of these with "lvdisplay")
lvol3
lvol4
lvol5
lvol6
lvol7
lvol8
lvol9,
etc.

Each of the above lvols are mirrored across both diska and diskb in vg00.

Right?

Re: Mirror Question

gigiz — Wed, 08 Mar 2006 08:49:21 GMT

Yes it's normal. In the Vgdisplay you can see a total PE primary disk + mirror disk.In the Logical Volume comumn you can see the Current and the Allocated Pe that exlain yout doubt !!!!