topic Re: Disk issue in Operating System - HP-UX

Disk issue

shikhar_1 — Thu, 27 Jan 2011 10:52:22 GMT

Hi,

I have facing issue is that i have configured rx2660 server with six sas drives attached to it.
Now when i installed OS on that it is showing only two disks. One disk for OS and other disk is showing combined of all rest five disks.
I am not understanding why five six has combined and showing it as a single disk.

H/W Scan: Thu Jan 27 15:45:21 2011
Path(s) Device File(s) Use VG Names Paths Size(GB) Descrip
--------------------------------------------------------------------------------
0/3/0/0/0/0.0.0 /dev/dsk/c0t0d0 LVM vg00 1 136.70 HP
0/3/0/0/0/0.0.1 /dev/dsk/c0t0d1 unused - 1 546.81 HP
--------------------------------------

# ioscan -funC disk
Class I H/W Path Driver S/W State H/W Type Description
=====================================================================
disk 0 0/3/0/0/0/0.0.0 sdisk CLAIMED DEVICE HP LOGICAL VOLUME
/dev/dsk/c0t0d0 /dev/rdsk/c0t0d0
/dev/dsk/c0t0d0s1 /dev/rdsk/c0t0d0s1
/dev/dsk/c0t0d0s2 /dev/rdsk/c0t0d0s2
/dev/dsk/c0t0d0s3 /dev/rdsk/c0t0d0s3
disk 1 0/3/0/0/0/0.0.1 sdisk CLAIMED DEVICE HP LOGICAL VOLUME
/dev/dsk/c0t0d1 /dev/rdsk/c0t0d1
disk 4 255/1/0.0.0 sdisk CLAIMED DEVICE TEAC DVD-ROM DW-224EV
/dev/dsk/c1t0d0 /dev/rdsk/c1t0d0

Re: Disk issue

Torsten. — Thu, 27 Jan 2011 10:58:42 GMT

You have a martarray controller installed, so you see logical drives (LUNs).

From ioscan get the /dev/ciss file and do

# sautil /dev/ciss_

and

# saconfig /dev/ciss_

to see the configuration details.

Re: Disk issue

shikhar_1 — Thu, 27 Jan 2011 11:20:17 GMT

Hi,

I am getting that /dev/ciss in ioscan command.

See the below o/p.

0/3/0/0/0/0 ext_bus PCIe SAS SmartArray P400 RAID Controller
0/3/0/0/0/0.0 target
0/3/0/0/0/0.0.0 disk HP LOGICAL VOLUME
0/3/0/0/0/0.0.1 disk HP LOGICAL VOLUME

Re: Disk issue

Torsten. — Thu, 27 Jan 2011 11:32:26 GMT

You say you are an expert in this area ...

# ioscan -fn

and you get sometging like

/dev/ciss1

now do

# sautil /dev/ciss1

and

# saconfig /dev/ciss1

I assume you have a RAID1 for the boot LUN and a RAID5 for the remaining disks.

No disk issue at all.

Re: Disk issue

shikhar_1 — Fri, 28 Jan 2011 06:51:40 GMT

Hi,

I have checked its showing this

---- LOGICAL DRIVE SUMMARY ---------------------------------------------------

# RAID Size Status

0 1+0 139979 MB OK
1 0 559929 MB OK

It means my root disk is mirrored and other disk are raid 0.
But my root disk is not mirrored.
Is there any way to split all my disks separate?

Re: Disk issue

Torsten. — Fri, 28 Jan 2011 08:07:00 GMT

Based on this very little piece of information you provided it looks like the boot disk is a RAID1 (mirrored).

A smartarray cannot allow access to the physical disks directly, but you can create several RAIDs (RAID1 or 5 or even 0) and logical drives within.

Re: Disk issue

Jorge Pons — Fri, 28 Jan 2011 11:31:51 GMT

Hi

Like Torsten said, you have several disk plugged into smartarray. this smartarray is configured in two volumes, one of this is in RAID1, for O.S, and the other one could be in RAID5, for data.
In case of the first one volume, the Smartarray present you like only one disk, and you think is not in mirror.

Regards, Jorge

Re: Disk issue

Torsten. — Fri, 28 Jan 2011 11:39:30 GMT

Please post the complete output of

# sautil /dev/ciss1

and

# saconfig /dev/ciss1

because we need some more details.

Re: Disk issue

shikhar_1 — Tue, 01 Feb 2011 08:12:03 GMT

Hi,

Pls find as the attached for sautil /dev/ciss0 output.

Re: Disk issue

Torsten. — Tue, 01 Feb 2011 09:23:52 GMT

Now you can see t clearly, disks in bay 3 and 4 are mirrored; disks in bays 5,6,7 and 8 are forming a RAID0.

You can work with saconfig to delete the RAID0 and create something different.

Re: Disk issue

Syed Muhammad Ali Haide — Tue, 01 Feb 2011 09:49:48 GMT

the disk appearing is configured in SAS controller as single disk with RAID. if you want to change to your desire configuration read man saconfig

Re: Disk issue

shikhar_1 — Wed, 02 Feb 2011 13:26:32 GMT

Hi,

As u r saying that disks in bay 3 and 4 are mirrored but while checking it is not showing mirrored.

LV Name /dev/vg00/lvol3
VG Name /dev/vg00
LV Permission read/write
LV Status available/syncd
Mirror copies 0
Consistency Recovery MWC
Schedule parallel
LV Size (Mbytes) 1024
Current LE 32
Allocated PE 32
Stripes 0
Stripe Size (Kbytes) 0
Bad block off
Allocation strict/contiguous
IO Timeout (Seconds) default

--- Distribution of logical volume ---
PV Name LE on PV PE on PV
/dev/disk/disk2_p2 32 32

Re: Disk issue

Torsten. — Wed, 02 Feb 2011 13:52:47 GMT

The disks are hardware mirrored by the controller.

For the OS this is like a single normal disk (logical volume in ioscan means it is a LUN, not a disk).

Re: Disk issue

Duncan Edmonstone — Wed, 02 Feb 2011 13:54:55 GMT

Do you understand the difference between software RAID and hardware RAID?

LVM provides the capability to implement RAID through software.

THe SmartArrray array controller you have in your system which you are getting the configuration of via the saconfig command is hardware RAID.

You can see from the output of saconfig that drives 3 and 4 are in a hardware RAID configuration:

---------- LOGICAL DRIVE 0 ----------

Device File = /dev/dsk/c0t0d0
RAID Level = 1+0
Size = 139979 MB
Stripe Size = 128 KB
Status = OK

Participating Physical Drive(s):

Ct Enc Bay WWID
2I 1 4 0x5000c5001d48ec59
2I 1 3 0x5000c5001d44aa4d

This hardware RAID is presented as a single disk (c0t0d0) to the OS, and your root volume group is installed on this disk. LVM won't show a mirror as it isn't responsible for mirroring this disk.

HTH

Duncan