topic Re: RAID 1+0 setup in Operating System - HP-UX

RAID 1+0 setup

Rita Li — Sat, 27 Jan 2007 05:15:06 GMT

I have a new rx4640 server setup by the HP Engineer recently

I have 3 Volume Groups

vg00 - 2 x 72G disks, setup as mirror disks & I can successfully check from SAM that the setup is correct

vg01 - 6+6 72G disks, setup as RAID 0+1, with 6 file systems with 72G (2x72G physical) as a result. But from SAM, it says Mirror copies = 0. Also "lvdisplay" shows each file system is with Stripe = 0.

vg02 - 1+1 72G disks, setup as RAID 0, with 1 file system & both SAM & "bdf" both show the setup is correct

My doubt is: from SAM, /etc/fstab & "lvdisplay", I compared the file systems for vg01 & vg02 where they all show me the same setings. How can I know that the vg01 is really setup as RAID 0+1 that it should?

Rita

Re: RAID 1+0 setup

Hein van den Heuvel — Sat, 27 Jan 2007 11:23:53 GMT

>> I have a new rx4640 server setup by the HP Engineer recently

So ask the engineer to describe what has been set up?

>> My doubt is: from SAM, /etc/fstab & "lvdisplay", I compared the file systems for vg01 & vg02 where they all show me the same setings. How can I know that the vg01 is really setup as RAID 0+1 that it should?

Are you sure it is software stripe+mirror or perhaps in hardware for example by using a raid controller like a SmartArray.

I think you need to go a step up (down) from
lvdisplay to 'vgdisplay' and look for PVGs and such.

A whie ago i made a littel perl script to help present vgdisplay information. You'll find it attached. Give that a whirl?

If further help is needed then please provide more details, notably on the disk controllers involved. You may want to attach a .TXT file with output from relevant commands (vgdisplay, ioscan -funC disk, fcmsutil,... )

hth,
Hein van den heuvel
HvdH Performance Consulting

Re: RAID 1+0 setup

Rita Li — Sat, 27 Jan 2007 11:41:46 GMT

Hein,

Running your perl script provides an output as:

Type Name Stripes Allocated Total Free
---- ------------------------------ -- -------- -------- --------
VG /vg00 138176 138176 0
LV /vg00/lvol1 2 800 0 0
LV /vg00/lvol2 2 32000 0 0
LV /vg00/lvol3 2 1024 0 0
LV /vg00/lvol4 2 49312 0 0
LV /vg00/lvol5 2 20000 0 0
LV /vg00/lvol6 2 12000 0 0
LV /vg00/lvol7 2 1024 0 0
LV /vg00/lvol8 2 12000 0 0
LV /vg00/lvol9 2 10016 0 0

PV /dsk/c2t1d0s2 0 69088 0
PV /dsk/c2t0d0s2 0 69088 0

VG /vg01 416704 416704 0
LV /vg01/mfgpro2 1 70000 0 0
LV /vg01/mfgdata1 1 70000 0 0
LV /vg01/mfgdata2 1 70000 0 0
LV /vg01/mfgdata3 1 70000 0 0
LV /vg01/develop 1 70000 0 0
LV /vg01/develop2 1 66704 0 0

PV /dsk/c10t0d0 0 416704 0

VG /vg02 138896 138896 0
LV /vg02/develop3 1 138896 0 0

PV /dsk/c10t0d1 0 138896 0

Re: RAID 1+0 setup

Torsten. — Sat, 27 Jan 2007 11:51:57 GMT

Hi,

your vg01 is sitting on this device:

disk 3 0/5/1/0/4/0.0.0 sdisk CLAIMED DEVICE HP LOGICA
L VOLUME
/dev/dsk/c10t0d0 /dev/rdsk/c10t0d0

"HP LOGICAL VOLUME" means this is a hardware RAID (smartarray), so the LVM mirroring is not used, but the array controller will mirror the data across the disks.

Have a look at "man sautil" to get more information.

Re: RAID 1+0 setup

Hein van den Heuvel — Sat, 27 Jan 2007 12:01:59 GMT

Right, so as suspected the VG00 is really two physical drives directly in the box and has software mirroring through LVM

The other volumess are behing an array controller where hardware is doing the mirroring (and striping) but that is entirely transparant to Hpux.

Btw ... the 'nice round number' of 70000 on the LV size is always a dead give-away for a logical device behind a controller. It is hand picked number, not a device imposed odd number. The last LV clearly was assigned 'the slop'.

Trust but verify! You did, and all is well.

hth,
Hein.

Re: RAID 1+0 setup

Rita Li — Sun, 28 Jan 2007 02:14:20 GMT

I understand more about my rx4640 server now.

Thanks for all the answers

Rita