unmounting logical volumes

[Leonard G]

Hi,

I am new to working on Unix.
I had installed HP UX 11.11 on my server and went with the defaults. So, my root volume was given 200MB. I wanted to increase the size of this volume. According to the doc's I referred, I was asked to unmount the corresponding volumes iin the single user mode and use 'lvextend'.
But when I tried to do so it said 'the volume is busy cant unmount'. So on the suggestion of a co-worker I was asked to change the 'fstab' file. When I #'ed out the logical volumes that i didnt need to mount, now I am unable to log onto my server.

What can be done now ?? Please help !!

[Luk Vandenbussche · Accepted solution]

Hi Leonard.

You cannot increase the size of root volume.
You must reinstall the os

From default with the cdrom or from an ignite tape our server.

Several threads exist on this topic.

Just search for 'increase root filesystem'

Good luck

[Leonard G]

Thanks Luk,

I kept the reinstallation as the last resort but now that I can't increase the size of root without reinstallation, can I increase the size of all other volumes by unmounting and using 'lvextend', if yes, please tell me how to go into the single user mode to do so ??

[Luk Vandenbussche]

Hi,

Check this link for booting in single user mode
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=981460

You can extend every filesystem except / and /stand in single-user mode

PS : Thx for the points

[Andrew Rutter]

hi,

boot in to single user mode by stopping the server from booting at pdc level.

press any key to discontinue boot

from main menu type
boot pri

then select yes to interact with ISL

from here type
hpux -is

Then system will boot into single user mode.

From here you first need to sort out the fstab file first really.

Then you can umount and extend the lvols as required.

#mount -a
note the dev/vgxx/lvolx for which you want to extend
#umount /usr for example
#lvextend -L (new size in MB) /dev/vgxx/lvolx
#extendfs -F vxfs /dev/vgxx/rlvolx
#mount /dev/vgxx/lvolx /usr

f(ill in the x as required)

#reboot

also before you do any changes in fuure its always a good idea to make a backup kernal to boot from aswell.

Andy

[Wang,MinJie]

Hey.
You know what,if you've installed OnlineJFS Software on your system,you needn't go to single user mode to extend you volume even You can even extend it without unmounting!
You can :
lvextend -L (size you want it to be in MB) volumename;
fsadm -b (the volume size in KB) mountpointname;
OK!

[Adisuria Wangsadinata_1]

Hi,

FYI, you cannot extend the / and /stand file system.

For others, you can extend it online by using OnlineJFS (purchaseable software) or by LVM basic.

For the LVM basic, you need to goto single user to umount the filesystem. Here is the steps to goto single user :

1) Backup the filesystem before extending


2) Display disk information on the logical volume

lvdisplay -v /dev/vgXX/lvolYY | more


Make sure this is enough Free PE's to increase this filesystem.
Make sure that allocation is NOT strict/contiguous.


3) Reboot the machine

shutdown -r now


4) When prompted, press "ESC" to interrupt the boot.


5) Boot from the primary device and invoke ISL interaction.

bo pri isl

NOTE: If prompted to interact with ISL, respond "y"


6) Boot into single user mode

hpux -is

NOTE: Nothing will be mounted.

After you're in the single user mode, you can do the extend process. Here is some documents for your reference :

docID : KBRC00017432
Extending /var, /usr, /tmp without Online JFS :
http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000081573074

docID : KBRC00003170
How to extend a filesystem using Online JFS, Base JFS or HFS.
http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000080080515

For / & / stand, you can extend this file system by re-install OR by using the feature from Ignite/UX software (the command is : make_tape_recovery).

Hope this information can help you.

Cheers,
AW

[Mridul Shrivastava]

If u want to increase the size of root (/) particularly, the only way u can do is take ignite backup (using make_tape_recovery) and restore it. While restoring u can modify the filesystem sizes and all other things will remain same i.e. if any driver etc is loaded u need not to install them again.
This is the easiest and only way to modify root (/). Because these filesystem must be contigous so u can't modify it using single user mode etc.

[Yogeeraj_1]

hi,

Why would you want to increase the size of the root fie system?

It is ususally not recommended to install any "custom application" on this.

My system has the following:
# bdf /
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lvol3 204800 83904 119984 41% /

Any space i require is then mounted on another new lv.

E.g.
# bdf /BACKUP
Filesystem kbytes used avail %used Mounted on
/dev/vg00/lv_backup
13312000 11369696 1907882 86% /BACKUP


kind regards
yogeeraj

[Senthil Kumar .A_1]

Hi Leonard,

To recover your OS, you have 2 options.

1) Try booting into single user mode. first as follows,

Interrupt the PDC at the start and issue the command "bo pri"

When asked interact with ISL, issue "Y"

Then at HPUX> prompt issue, "hpux -is" to boot into single user mode. If it boots fine, correct the /etc/fstab file and remove the "#" that were added. If you are not able to boot into single user mode,try step 2.

2) try boot in "LVM maintenence mode". this you do by following..

Try booting into single user mode. first as follows,

Interrupt the PDC at the start and issue the command "bo pri"

When asked interact with ISL, issue "Y"

Then at HPUX> prompt issue, "hpux -lm" to boot into lvm maintenece mode.

Please note that root will not be mount on "/" . Instead it woudl be mounted on /dev/root. now edit /dev/root/etc/fstab if possible, never tried before, and remove those "#"s... and reboot with following command... Very imp[ortant with the command "reboot -n" ....

Now if this recovers the rootdisk abd boots successfully, I have a method to increase the root volume. the activity needs to be done in LVM maintence mode with the help of "pvmove" command because the extent allocation in lvol3 needs to be contiguous. This activity can be done without reinstalling. But, more on this activty later , based on your response in recovering the OS,

Regards and best wishes,

Senthil Kumar .A

[Jerry.P.Antony]

I agree with Senthil..You can extend root filesystem in maintenance mode, without reinstalling the OS.But I dont think HP is recommending this method..

[Senthil Kumar .A_1]

Hi leonard,

Just following up, any update related to this issue. Did you extend it successfully as suggested.

Regards,
Senthil Kumar .A