Boot/Root disk Mirroring

[John Jayaseelan]

Hi,

The Essential LV's in the Volume Group VG00 is mirrored.

How to check whether alternate boot disk is enabled or not? If not the procedure to implement alternate Boot disk enabling.

Please tell what would be system status if the disk through which system is booted, would the system be in the stable operating mode because all the LV' are mirrored.

Thanks
John Jayaseelan

[Joseph Loo]

Hi,

#lvdisplay -v /dev/vg00/lvolXX
you would notice status for each PE seen under Logical extents.

#setboot
to display whether autoboot is on and the alternate boot path.

regards.

[Jean-Louis Phelix]

Hi,

You can also have a look to "lvlnboot -v /dev/vg00"

Regards.

[Sunil Sharma_1]

Hi,

best way is
#lvdisplay -v
#lvlnboot
and

booting parameters
like auto boot should be enable
and Auto file of both mirrored disk
-lq argument should be there so in case of one disk fail it can boot from other disk.

Sunil

[Joseph Loo]

to add:

you may refer to Knowledge Base, DocId: KBRC00002335 on enable autoboot:

At the isl prompt, enter autoboot:

ISL> autoboot
Enter ON or OFF:on

Verify the content of the auto-execute file.

ISL> lsautofl
....... This should return something like:
Auto-execute file contains:
hpux


If needed, create the autofile.
This can be done at the command line or at the isl prompt....

At the isl prompt:
ISL> hpux set autofile

At the command line:
#mkboot -a <"auto string"> /dev/dsk/

Note: auto string = "hpux" or "hpux -lq" for mirrored root drive
And "device file" is for the boot device

------------

[Geoff Wild]

lvlnboot -v /dev/vg00
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c28t5d0 (0/0/0/3/0.5.0) -- Boot Disk
/dev/dsk/c0t6d0 (1/0/0/3/0.6.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c28t5d0
/dev/dsk/c0t6d0
Root: lvol3 on: /dev/dsk/c28t5d0
/dev/dsk/c0t6d0
Swap: lvol2 on: /dev/dsk/c28t5d0
/dev/dsk/c0t6d0
Dump: lvol2 on: /dev/dsk/c0t6d0, 0


If you don't see 2 Boot Disk's then your mirror is NOT bootable.

To recreate from scratch:

Mirror the root lvols:

pvcreate -B /dev/rdsk/c3t6d0
vgextend /dev/vg00 /dev/dsk/c3t6d0
mkboot -l /dev/rdsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol1 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol2 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol3 /dev/dsk/c3t6d0
/usr/sbin/lvlnboot -b /dev/vg00/lvol1
/usr/sbin/lvlnboot -s /dev/vg00/lvol2
/usr/sbin/lvlnboot -r /dev/vg00/lvol3
lvextend -m 1 /dev/vg00/lvol4 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol5 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol6 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol7 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol8 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol9 /dev/dsk/c3t6d0
lvextend -m 1 /dev/vg00/lvol10 /dev/dsk/c3t6d0


Rgds...Geoff

[John Jayaseelan]

Hi,

Following are the details. So the alternate boot disk is bootable. Please tell what would be system status if the disk through which system booted is failed , would the system be in the stable operating mode or not.

# lvlnboot -v /dev/vg00
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c1t11d0 (8/12.11.0)
/dev/dsk/c2t3d0 (10/0.3.0)
/dev/dsk/c2t5d0 (10/0.5.0) -- Boot Disk
/dev/dsk/c7t14d0 (10/8.14.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Root: lvol3 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Swap: lvol2 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Dump: lvol2 on: /dev/dsk/c2t5d0, 0
Dump: lv_swap2 on: /dev/dsk/c2t3d0, 1


Thanks

[Geoff Wild]

Yes, your system will be stable if the disk you booted fails...

Rgds..Geoff

[Alan Turner]

The system would be stable, but you would not have any redundancy to protect you against a further disk failure.
Also, if you needed to reboot, you would need to boot from the other disk (so set tit up as the alternate boot path, and set both boot paths with the "-lq" parameter so that each can be used to boot even if the othe ris not available.

[John Jayaseelan]

Alan,

Is not the system automatically bootable from other disk in case of a boot disk failure?

If not please what needs to be done in details.

Thanks

[John Jayaseelan]

Hi,

The alternate boot disk dev/dsk/c7t14d0 is in a HASS A3312A enclosure. Is it going to be a problem.

Thanks

[A. Clay Stephenson]

Booting from a disk in a HASS is not problem BUT only slots A1,A2,B1, and B2 are power-on first slots so the boot disk (primary or alternate) should be in one of those slots. If you need to move an existing disk module out of the way, simply powerdown , reset the DIP switches on the back of the HASS, move the disks, and power back up.

[Todd McDaniel_1]

one other thing...

I think you must have created the mirror with hpux -lm specified. so that it will boot without a quorum, since the primary mirror would be down.

someone correct me if Im wrong... or else your system will stop at the ISL prompt wating for you to type: hpux -lm on the boot device.

[A. Clay Stephenson]

Actually, you need "-lq" rather than "-lm".
mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/rdsk/cXtYdZ should be issued for both the prmary and alternate boot disks.

[Todd McDaniel_1]

oopsie my bad on that hehe, m is for maintenance mode...


no points here...

[John Jayaseelan]

Hi,

The disk is on b1 slot of the HASS array. SO the following command should be enough for enabling the auto boot from either of the disk during the reboot even either of the disks is failed.

mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c2t5d0 /dev/dsk/c7t14d0

Can this be run during the system being used?

Thanks
system being used.

[A. Clay Stephenson]

Yes, the mkboot command can be issued while the machine is up but you need to issue two separate mkboot -a's specifying diffrent disks each time. The SAFE way to do this is to do your mkboot -a on the alternate and boot from it. When you know that it is a good boot disk then do the mkboot -a on the primary. You want the -lq on both disks because you do not want the boot to hang is either the primary or alternate is unavailable.

[John Jayaseelan]

Hi,

mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c2t5d0
mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c7t14d0

The above should do it.

Thanks

[John Jayaseelan]

Hi,

The following are the current config. Should this to be run 'mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c2t5d0
mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c7t14d0' to make the system bootable from either of the disk in case the other disk fails.

______________
# lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group:
/dev/dsk/c1t11d0 (8/12.11.0)
/dev/dsk/c2t3d0 (10/0.3.0)
/dev/dsk/c2t5d0 (10/0.5.0) -- Boot Disk
/dev/dsk/c7t14d0 (10/8.14.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Root: lvol3 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Swap: lvol2 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Dump: lvol2 on: /dev/dsk/c2t5d0, 0
Dump: lv_swap2 on: /dev/dsk/c2t3d0, 1

[ccprod01]: /root
# lifcp /dev/rdsk/c2t5d0:AUTO -
hpux -lq
[ccprod01]: /root
# lifcp /dev/rdsk/c7t14d0:AUTO -
hpux (;0)/stand/vmunix
[ccprod01]: /root
# echo 'boot_string/S' | adb /stand/vmunix /dev/mem
boot_string:
boot_string: disc(10/0.5.0;0)/stand/vmunix ----/dev/rdsk/c2t5d0
[ccprod01]: /root

______________

Thanks

[John Jayaseelan]

Hi,

The following are the current config.
______________
# lvlnboot -v

Boot Definitions for Volume Group /dev/vg00:

Physical Volumes belonging in Root Volume
Group:
/dev/dsk/c1t11d0 (8/12.11.0)
/dev/dsk/c2t3d0 (10/0.3.0)
/dev/dsk/c2t5d0 (10/0.5.0) -- Boot Disk
/dev/dsk/c7t14d0 (10/8.14.0) -- Boot Disk
Boot: lvol1 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Root: lvol3 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Swap: lvol2 on: /dev/dsk/c2t5d0
/dev/dsk/c7t14d0
Dump: lvol2 on: /dev/dsk/c2t5d0, 0
Dump: lv_swap2 on: /dev/dsk/c2t3d0, 1

# lifcp /dev/rdsk/c2t5d0:AUTO -
hpux -lq

# lifcp /dev/rdsk/c7t14d0:AUTO -
hpux (;0)/stand/vmunix

# echo 'boot_string/S' | adb /stand/vmunix /dev/mem
boot_string:
boot_string: disc(10/0.5.0;0)/stand/vmunix ----/dev/rdsk/c2t5d0
______________

Should the following to be run to make the system bootable from either of the disk in case the other disk fails.

'mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c2t5d0
mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/c7t14d0


Thanks