topic Re: Mirror bootable disk in Operating System - HP-UX

Mirror bootable disk

Anjaneyulu — Thu, 30 Oct 2008 09:35:12 GMT

Hi,

I have two doughts

1) How can we get the how many cpu's are added to my server. and cpu's information

2) Why we create the mirror bootable disk. How we know which disk is used for system disk. and how we select the disk for mirror bootable disk.

Re: Mirror bootable disk

Aneesh Mohan — Thu, 30 Oct 2008 09:42:46 GMT

Hi Anjan,

How many CPU cores

#ioscan -fnkC processor

or

#top

or

#sam >performance monitors>system properties>processor

For detailed information of the CPU`s
====================================

#echo "selclass qualifier cpu;info;wait;infolog" | /usr/sbin/cstm

Re: Mirror bootable disk

Torsten. — Thu, 30 Oct 2008 09:43:43 GMT

1) run

# ioscan -fnCprocessor

Information depends on server platform and OS version.

For Integrities you can use

# machinfo

2) For redundancy. If one of the disks fails, your system will continue to run.

Boot disks are usually part of vg00, run

# vgdisplay -v vg00
and
# lvlnboot -v

to get this information.

How to mirror? See appendix here:

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

Re: Mirror bootable disk

Aneesh Mohan — Thu, 30 Oct 2008 09:49:03 GMT

> 2) Why we create the mirror bootable disk. How we know which disk is used for system disk. and how we select the disk for mirror bootable disk.

Mirror bootable disk is for redundancy purpose,Suppose if your primary boot disk got failed you can run the show using the mirrored one (You can have maximum 2 copies)

The below command give you the existing boot disks information
#lvlnboot -v

You have to buy Mirror Unix software for doing this (It is based on No of active cpu cores)

Miroring the root volume group:
-----------------------------

1) swlist -l bundle

This will display MirrorDisk/UX if installed on the system. If MirrorDisk/UX isn't found, then it will need to be loaded. This product **is not** part of the standard Core-OS, It must be purchased.

2) pvcreate -fB /dev/rdsk/c1t2d0 The -B option is used to create a bootable Physical Volume.

3) vgextend vg00 /dev/dsk/c1t2d0 This adds the Physical Volume to the root volume group.

4) mkboot /dev/rdsk/c1t2d0 Make sure to use the character device file when using mkboot.

5) mkboot -a "hpux (;0)/stand/vmunix" /dev/rdsk/c1t2d0 **** or ****
mkboot -a "hpux -lq" /dev/rdsk/cXtXdX **** on both disks !!! ***

6) lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c1t2d0

This command extends the mirror to the specified Physical Volume.

**NOTE: The lvextend command must be done on all logical volumes on the primary disk. This means that lvextend has to be done on lvol1 -> lvolX. This also includes /dev/vg00/lvol2, which by default is primary swap. lvol1 must be the first logical volume mirrored; if it is not, then you will not be able to boot from the mirror.

7) lvlnboot -b /dev/vg00/lvol1 Specifies the boot "/stand" logical volume (10.20 & 11.0)

8) lvlnboot -r /dev/vg00/lvol3 Specifies the root "/" logical volume.

***NOTE: The root logical volume is /dev/vg00/lvol1 for HP-UX 10.01 & 10.10, and /dev/vg00/lvol3 (as in this example) is the root logical volume in 10.20 & 11.0.

9) lvlnboot -s /dev/vg00/lvol2 Specifies the swap logical volume.

To determine where the swap logical volume is located use the swapinfo command.

10) lvlnboot -d /dev/vg00/lvol2 Specifies the dump logical volume.

11) lvlnboot -R Recovers any BDRA info.

12) lvlnboot -v Verify boot, root, swap and dump settings.

13) setboot This displays the currently set Primary and Alternate boot paths.

14) setboot -a mirror_disk_hardware_address Changes the Alternate Boot Path to the path of the Root Mirror.

15) shutdown -r now Reboot with no grace period

Thanks,
Aneesh

Re: Mirror bootable disk

Suraj K Sankari — Thu, 30 Oct 2008 09:52:16 GMT

Hi,

>>1) How can we get the how many cpu's are added to my server. and cpu's information
To useing this commands you can find how many cpu's are install into your system

top
ioscan
machinfo
sam

>>2) Why we create the mirror bootable disk.

If primary disk got bad then we can use the mirror copy of bootable disk.

>> How we know which disk is used for system disk. and how we select the disk for mirror bootable disk.

To find out Which are the bootable disk give this command
lvlnboot -v

Suraj

Re: Mirror bootable disk

Ganesan R — Thu, 30 Oct 2008 09:53:04 GMT

Hi,

>>1) How can we get the how many cpu's are added to my server. and cpu's information<<

# ioscan -fnkC processor
# echo "selclass qualifier cpu;infolog" | /usr/sbin/cstm | grep "CPU Module"
# echo itick_per_usec/D | adb -k /stand/vmunix /dev/mem

Above commands will give you the processor details.

>>2) Why we create the mirror bootable disk. How we know which disk is used for system disk. and how we select the disk for mirror bootable disk.<<

Not much clarity on your second question. Anyway Mirror bootable disk is to boot the system in the event of primary disk failure.
You need to find the free disk to create mirror disk. use ioscan command to get the list of available disks. you can compare this #ioscan -fnC disk output with #strings /etc/lvmtab output to find the free disks.

Disks part of root volume groups(mostly vg00) are the system disks.

If you can clearly explain what you need we can explain further..

Thanks

Re: Mirror bootable disk

Johnson Punniyalingam — Thu, 30 Oct 2008 10:09:15 GMT

Hi,

1) How can we get the how many cpu's are added to my server. and cpu's information

step 1:- ioscan -fnkC processor

# ioscan -fnkC processor
Class I H/W Path Driver S/W State H/W Type Description
===================================================================
processor 0 33 processor CLAIMED PROCESSOR Processor

step 2:- SAM

step 3:- cstm --> for more specfic details

2. Why we create the mirror bootable disk..?

to avoid single point of failure

How we know which disk is used for system disk...?

Example:-

# lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c1t2d0 (0/0/1/1.2.0) -- Boot Disk --> PRIMARY disk
/dev/dsk/c2t2d0 (0/0/2/0.2.0) -- Boot Disk Aleternative boot disk
Boot: lvol1 on: /dev/dsk/c1t2d0
/dev/dsk/c2t2d0
Root: lvol3 on: /dev/dsk/c1t2d0
/dev/dsk/c2t2d0
Swap: lvol2 on: /dev/dsk/c1t2d0
/dev/dsk/c2t2d0
Dump: lvol2 on: /dev/dsk/c1t2d0, 0

3. how we select the disk for mirror bootable disk..?

Once you system booting up

Interrupt the boot process when prompted for it by pressing another keys

Main Menu > BO eg BO Pri --> refer to primary disk or eg BO Alt --> refers to "Mirror disk" or "Alternative disk"

eg Bo 0/0/2/0.2.0 --> refer to your HW_path of your mirror_disk

Interact with IPL? > N

now the server is booted with your "mirror_disk"

Thanks,
Johnson

Re: Mirror bootable disk

Anjaneyulu — Thu, 30 Oct 2008 10:24:08 GMT

Hi, Thanks to All.

My dought is which type of disk selected for mirror bootable disk. I mean we can any disk.or any rules for select the mirror bootable disk

Re: Mirror bootable disk

Ninad_1 — Thu, 30 Oct 2008 10:27:38 GMT

Hi,

To determine which disk the currently running kernel was booted from, use
adb as follows (must be root):

# KERNEL=/stand/vmunix # set this var to the currently running kernel
# echo 'boot_string/S' | adb $KERNEL /dev/mem | grep /
boot_string: disc(8/4.5.0;0)/stand/vmunix

Regards,
Ninad

Re: Mirror bootable disk

Ganesan R — Thu, 30 Oct 2008 10:32:23 GMT

Hi,

It is preferred to use internal disk for mirror boot disk. And also it would be better if it is in different controller.

The reason is that if both primary and mirror disks are in different controller we can achieve high availablity one step higher.
If both primary disk and its controller also fails still we can run the server since mirror disk is connected to another controller.

Hope it helps.

Re: Mirror bootable disk

Johnson Punniyalingam — Thu, 30 Oct 2008 13:37:01 GMT

Hi,

>> My dought is which type of disk selected for mirror bootable disk. I mean we can any disk.or any rules for select the mirror bootable disk <<

Yes ..you can choose Any disk and which does not belong to any volume_group,

simple rule :-
============
also mirror disk should be same capacity /size of you another root disk and better if in different controller.

Create a boot area on the mirror disk.

mkboot /dev/rdsk/c1t5d0
mkboot â a "hpux â lq" /dev/rdsk/c1t5d0
lvextend -m 1 for all of the logical volumes to the include the mirrror disk

List files in the mirrors lif area

lifls /dev/rdsk/c1t5d0 - This should return the following:

ISL AUTO HPUX PAD LABEL

Verify that "hpux â lq" is in the AUTO file on both disks.

lifcp /dev/rdsk/c1t5d0:AUTO -

lifcp /dev/rdsk/c1t4d0:AUTO â

3. Reboot the system using the mirror disk.

shutdown â r â y 0

Break during the boot sequence.

BOOT_ADMIN> boot 8/8.5.0 -->

Thanks,
Johnson