How to know from which harddisk machine boots in LVM

[Guna_2]

Hi

I am having 2 36GB harddisks with LVM mirroring in my HP Box. From this 2 harddisk how can i find out at present from which harddisk machine has booted.


If any one knows pls tell me.

Regards
Guna

[nishith]

hii guna!!

below command gives the disk from which HP-UX machine booted.

#echo boot_string/S | adb /stand/vmunix /stand/kmem

regds,
nishith.

[Indrajit Bhagat]

please use the command #lvlnboot -v

[Torsten.]

Hi,

you will find this information in the syslog too (boot disk ...).

[Sp4admin]

Hello,

you can use the lvlnboot -v command. or if you have just rebooted and not sure just check dmesg.

sp,

[Mridul Shrivastava · Accepted solution]

Execute the following command to determine the boot device :

# echo "bootdev/X" | adb /stand/vmunix /dev/kmem

this will give an output similar to :

bootdev:
bootdev: 1F005000

This number represents the boot device. Here's how to decode it :

1F 00 5 0 00
__ __ _ _ __
| | | | |
major# | target | flags
| |
bus# lun

Per this information:

major# (1F) is 31 in decimal, and major number 31 should be sdisk on your
system (you can use lsdev to verify this).

bus# (00) is the card instance number to which the device is attached.

target (5) is the device's scsi id.

lun (0) is the device's logical unit number.


Therefore, this device maps to /dev/dsk/c0t5d0.

[Raj D.]

Guna ,

Here is a easy one,

# echo boot_string/S|adb /stand/vmunix /dev/mem

for 11vi

For 11iv2 the command is slightly different. check the man adb for 11.23


hth,
Raj.

[Arun michael]

Dear Guna;
Use the simple command lvlnboot -v which will solve your doubt

[Doru Iulian Barit]

Hi.
Try setboot command.

[Guna_2]

Thanks @ all

1) The lvlnboot -v shows both the harddisk. From that how will we fild out the boot harddisk in a mirroring setup


2) echo bootstring/S | adb /stand/vmunix /dev/mem is showing exactly the detail of currently bootd harddisk hw path

3) setboot shows only the primary and alternate path only . If the machine booted on alternate path how will we comes to know that.


4) And /stand/bootconf file shows the presently booted harddisk hw path.

Once again Thanks to all of You

Regards,
Guna

[Guna_2]

Hi


In syslog i am not finding any entry as bootstring or bootdisk


IS there any other option

Regards,
Guna

[Kasper Hedensted]

Hi Guna,

"lvlnboot -v" displayes both disks, but it will display the text "Boot Disk" next to the one that the system was booted from.

you could use:

lvlnboot -v |grep "Boot Disk"

[Guna_2]

Hi Kasper Hedensted

lvlnboot -v shows the both harddisk as boot disk. Because the hp box have root mirror. So in this case how can we find out from which harddisk the kernel has loaded.

Thanks and Regards,
Guna

[Ivan Krastev]

Check syslog :
# grep "Boot device" /var/adm/syslog/syslog.log

regards,
ivan