To extend the logical volumes for /tmp, /home, /opt, /var, /usr,  the filesystem must first be unmounted . While in multi-user mode ,  if you try to unmount these logical volumes you will receive the following error: DEVICE BUSY . This message is displayed even if the  command fuser -k /mountpoint is used . To unmount and extend these logical volumes, do the following:

 #** WARNING: IMPORTANT - Always have a known good, current backup of the system or at minimal , a backup of the filesystem that  will be extended .
 

 1) vgdisplay /dev/vg00

This command will give general info about the volume group. Look for the column FREE PE's . This field tells the total amount of free (not allocated) Physical Extents . If FREE PE's shows 0, then a logical volume will need to be reduced or moved to another volume group in order to free up the Physical Extents.  The size of the PE's can be determined by looking at the PE SIZE (Mbytes) field . The default  size is 4 . To determine the total unallocated disk space in Mbytes do the following:  FREE PE's * PE SIZE = Total unallocated Disk Space in Mbytes

2) lvdisplay /dev/vg00/lvolX

This command will give general info about the logical volume. Before extending the lvol, the current size
needs to  be determined . LV Size (Mbytes ) displays the current logical volume size . Another factor that needs to be checked is the  Allocation field .  If the output from lvdisplay shows :  Allocation  ->  strict/contiguous . The logical volume must have concurrent free PE's to attach the logical volume.  The strict setting is to prevent mirroring a logical volume to the same disk the primary logical volume resides.

3) Boot the system into single user mode

    a) shutdown -r now
        This will shutdown the system and then reboot

    b) Interrupt escape sequence
        When the system reboots, and starts coming back up, the following message will be displayed :  For 800's : To interrupt boot sequence press any key with in 10 seconds.  For 700's : to interrupt boot sequence press and hold the escape Key with in 10 seconds .  This will bring the system to the Boot Admin prompt.

    c) Boot from primary disk

        For 800's : The Boot Admin prompt will ask if you want to boot from the primary disk -> answer yes. It will then ask you if you want to interact with IPL -> answer yes . This will bring you to ISL>.   For 700's : The Boot Admin prompt will show a search option. This is to search for bootable devices . The internal scsi disk  in a 700 by default  is set at scsi 6. The display will show a letter P and a number next to the scsi setting :  Example -> P0 scsi6, Type bo P0 . This will ask if you want to interact with ISL.   -> answer yes . This will bring you to ISL>

    d) Boot into single usermode

        From ISL> type the following: hpux -is (;0)/stand/vmunix [ENTER] This will boot the system into single usermode.  To verify the run lever , once the system has booted up do the following: who -r   -> output will show init s or S

 4) Extend the logical volume

        When booting into single user mode, /usr, /var, /tmp, /home, and /opt may already be unmounted . By typeing the command : mount -a . All filesystems that are referenced in /etc/fstab will be mounted if they are currently unmounted. type bdf -> this will display all mounted filesystems . From this  output do one final verification of the name of the filesytem and and logical volume name.

    a) Unmount the filesystem.  After verifying the logical volume and filesystem to extend, unmount the filesystem :
                umount /dir-name
                umount /var                    # this example unmounted the /var filesystem .

    b) Extend the logical volume.   To extend the logical volume do the following:
                lvextend -L (Total size) /dev/vg00/lvolX .
In the following example we want to extend lvol4 to be total size of 400Mg.
                lvextend -L 400 /dev/vg00/lvol4
 A message should return that it was successful.

    c) Extend the filesystem.   After extending the logical volume, the file system must be extended. To do this , you issue the extendfs command.
                extendfs -F file-system-type /dev/vg00/rlvolX
In this example we will extend the filesystem for lvol4.
                extendfs -F vxfs /dev/vg00/rlvol4
This will return a message about new blocks or for an HFS file system new super blocks .  Note : If you are not sure what type of filesystem you have, you can check /etc/fstab or do /usr/sbin/fstyp /dev/vgname/lvolname.   NOTE: /usr must be mounted to use the fstyp command

 5) Remount the filesystem

        Issue the "mount -a" command to remount the file system. Do the "bdf" command to verify the new filesystem size.

 6) Reboot the system

        Issue the "shutdown -r now" command . This will bring the system back to multiuser mode .
 

******************************************************************************

What If I Don't Have Any Free PE's availible In /dev/vg00 ?

NOTE: See above WARNING messages before starting.

If the vgdisplay command displays that the field FREE PE's =0, one of the  following procedures will need to be done:
 A) Remove unused logical volumes
 B) Reduce a logical volume in /dev/vg00 to free up the PE's
 C) Move a logical volume to a different volume group to free up the PE's

 1) Determine if there are unused logical volumes in /dev/vg00

To determine what logical volumes are in /dev/vg00 do  the following command:
                vgdisplay -v /dev/vg00 |more.
This will display all logical volumes in /dev/vg00.*NOTE* lvol2 is the default  logical volume for swap . Verify the this logical volume is being used be typing swapinfo -t.   This will display all swap devices . Compare the output of  vgdisplay -v /dev/vg00 to the contents of /etc/fstab .   All matching logical volumes in general should not be removed . Verify that all non matching logical volumes are not being used by databases , developers , etc.

   a) Removing unused logical volumes. To remove unused logical volumes, issue the following  command:
                lvremove /dev/vgname/lvolname
                lvremove /dev/vg00/lvol18                 #  In this example we are removing lvol18
After removing all unused logical volumes, do the vgdisplay command to determine how many free PE's are now availible . Follow the above procedure .
 

 2) Determining what logical volume in /dev/vg00 can be reduced

To determine what logical volume you will reduce to free up PE's, do the bdf command. This will display all mounted file systems.Look at the percent used field and file system size field.
Example: If bdf shows /home is 300Mg, and only 30% of the filesystem is being used, this logical volume may be selected to be reduced to free up PE's. *NOTE* / and  /stand cant be reduced . These filesystems are exempt from this process.

   a) Reducing a logical volume.   Warning: reducing a logical volume corrupts the filesystem.  Insure that you have a known good backup of the filesytem before  reducing it. To reduce the logical issue the  following command: unmount /mountpoint .  In this example we'll reduce /home . /home filesystem size  is currently 300MG , and we will reduce it to 240Mg.  The lvolname is /dev/vg00/lvol9.  Example :
            umount /home
            lvreduce -L 240 /dev/vg00/lvol9

A message will display that the new selected size is smaller than current -> do wish to proceed. type yes and the logical volume  will be reduced.   At this point, it is very possible the file system is corrupt.Issue the newfs command, mount the file system and restore the data. Example :
           newfs /dev/vg00/rlvol9            # **NOTE** newfs is ran on the rlvolX device file.
           mount -a or mount /dev/vg00/lvolx /mountpoint.  Example:
           mount /dev/vg00/lvol9 /home
Restore the directory from your backup.  Issue the vgdisplay /dev/vg00 command to display the new FREE PE's.  Proceed with the above procedures.

 3) Moving a logical volume to a different volume group

To move a logical volume to a different volume group, the following steps will need to be done: vgdisplay on the volume group the logical volume will be moved to . Determine from the FREE PE's field if enough disk space is availible to create a logical volume of equal or greater size than the original. **NOTE** See above at vgdisplay for determining FREE PE's.

      a) Creating a logical volume.   A logical volume can be create either manually , or by using SAM to create the logical volume manually do one of  the following:
            lvcreate -L size -n name(optional) /dev/vgname
Example: We will create a 300Mg logical volume,  call new-home , on /dev/vg01
            lvcreate -L 300 -n new-home /dev/vg01
If you wish to have the logical volume on a specific disk in a volume group, do pvdisplay on the disk device to determine if there are enough PE's availible to create the logical volume  Example: We will create a 300Mg logical volume called new-home on /dev/dsk/c0t5d0 in volume group vg01:
            lvcreate -n new-home /dev/vg01
            lvextend -L 300Mg /dev/vg01/new-home /dev/dsk/c0t5d0
In either case, after creating  the logical volume do the following:   Example :
            newfs /dev/vg01/rnew-home
            mkdir /new-home                                                #Create a mount point for the new logical volume
            mount /dev/vg01/new-home /new-home           #mount the new filesystem
            bdf -> verify the lvol is mounted

   b) Transfer the data
     b.1)
         The data can be transfered several different ways. The safest but most time consuming is to do the following:  unmount the original logical volume and mount the mount point on the new logical volume and restore the data from a backup.
         Example: We will mount /home , which is currently on  /dev/vg00/lvol8 to /dev/vg01/new-home .
            umount /home
            mount /dev/vg01/new-home /home
bdf -> verify that the bdf reflects the new logical volume.   restore the data from backup . This will write to the new filesystem .
NOTE: IN ALL EXAMPLES, YOU MUST EDIT /etc/fstab TO REFLECT THE NEW LOGICAL VOLUME.

     b.2)
         Another method is to mount the new logical volume on a seperate mount point and use cpio or fbackup/frecover to transfer the data to the new logical volume. After that data is tranferred  unmount the new logical volume, unmount  the original logical volume and mount the new logical volume on the original mountpoint.   Example: We will transfer data from /home to /new-home and mount the new logical volume on /home.
            mount /dev/vg00/lvol9 /home
            mount /dev/vg01/new-home /new-home
Either of the following commands can be used to transfer the data.
            fbackup -i /home -f - | (cd /new-home; frecover -Xrf -)
or
            cd /home
            find . -name -print -depth |cpio -pdmhlvxu /new-home
After data transfer is complete , do the following:   umount /home ,  umount /new-home .  Boot the system backup into multi-user mode and verify the new logical volume is being mounted. If all appears to be working fine.  IE: users can login , applications run fine,  then remove the original logical volume.   Once again do the vgdisplay command to verify to free available PE's .  At this point proceed with extend the logical volume in /dev/vg00
            mount /dev/vg01/new-home /home
            bdf     ->verify the bdf reflects the new logical volume.
            Edit /etc/fstab to reflect the new logical volume.
            newfs /dev/vgname/rlvolname
            lvreduce -L total-reduced-size /dev/vgname/lvolname
that will be extended.  Strict is the default  settings for all logical volumes ,  unless manually created with strict policy set to off.