Root File System Extension in HP-Unix

This article explains how to extend the root (/) file system using LVM Mirror/UX. OnlineJFS is required to extend the file system without going in LVM maintenance mode. This method allows to extend root (/) file system without re-igniting the server.

It uses a special "reserve" logical volume as stepping stone to free the required PEs between current lvol3 and lvol4 to comply with lvol3 contiguous policy. This method can be used on HP-UX 11.11 / 11.23 with Legacy Addressing (/dev/dsk/c#t#d#) or with the new HP-UX 11.31 Agile Addressing (/dev/disk/disk#) device special files. In this example, we use the new HP-UX 11.31 Agile Addressing.

1.   Create full backup of /dev/vg00 volume group using Ignite, if available.

# make_tape_recovery -v -I -x inc_entire=vg00 -a /dev/rmt/#mn

2.   Check the current status of your volume groups and logical volumes.

boxnet:/root#bdf       Filesystem          kbytes    used   avail %used Mounted on /dev/vg00/lvol3    2097152  290496 1792600   14% / /dev/vg00/lvol1    2097152  199152 1883256   10% /stand /dev/vg00/lvol10   8388608 2372536 5974544   28% /var /dev/vg00/lvol12   4194304   20848 4140864    1% /var/adm/crash /dev/vg00/lvol11   2097152   20776 2060168    1% /var/SAN /dev/vg00/lvol9    8388608 3253432 5095160   39% /usr /dev/vg00/lvol8    1048576   22904 1017744    2% /tmp /dev/vg00/lvol5    9355264 5333416 3990488   57% /opt /dev/vg00/lvol7    2097152   20776 2060168    1% /opt/networker /dev/vg00/lvol6    2097152   20776 2060168    1% /opt/SAN /dev/vg00/lvol4    1048576   21216 1019456    2% /home boxnet:/root#vgdisplay -v vg00 --- Volume groups --- VG Name                     /dev/vg00 VG Write Access             read/write     VG Status                   available                 Max LV                      255    Cur LV                      12     Open LV                     12     Max PV                      16     Cur PV                      2      Act PV                      2      Max PE per PV               4329         VGDA                        4   PE Size (Mbytes)            16              Total PE                    8638    Alloc PE                    6262    Free PE                     2376    Total PVG                   0        Total Spare PVs             0              Total Spare PVs in use      0                     VG Version                  1.0       VG Max Size                 1108224m   VG Max Extents              69264            --- Logical volumes ---    LV Name                     /dev/vg00/lvol1    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                256            Used PV                     2          LV Name                     /dev/vg00/lvol2    LV Status                   available/syncd              LV Size (Mbytes)            8192               Current LE                  512          Allocated PE                1024           Used PV                     2          LV Name                     /dev/vg00/lvol3    LV Status                   available/syncd              LV Size (Mbytes)            2048                Current LE                  128          Allocated PE                256            Used PV                     2          LV Name                     /dev/vg00/lvol4    LV Status                   available/syncd              LV Size (Mbytes)            1024               Current LE                  64           Allocated PE                128            Used PV                     2          LV Name                     /dev/vg00/lvol5    LV Status                   available/syncd               LV Size (Mbytes)            9136               Current LE                  571          Allocated PE                1142           Used PV                     2          LV Name                     /dev/vg00/lvol6    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                256            Used PV                     2          LV Name                     /dev/vg00/lvol7    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                256            Used PV                     2          LV Name                     /dev/vg00/lvol8    LV Status                   available/syncd              LV Size (Mbytes)            1024               Current LE                  64           Allocated PE                128            Used PV                     2          LV Name                     /dev/vg00/lvol9    LV Status                   available/syncd              LV Size (Mbytes)            8192               Current LE                  512          Allocated PE                1024           Used PV                     2          LV Name                     /dev/vg00/lvol10    LV Status                   available/syncd              LV Size (Mbytes)            8192               Current LE                  512          Allocated PE                1024           Used PV                     2          LV Name                     /dev/vg00/lvol11    LV Status                   available/syncd              LV Size (Mbytes)            2048                Current LE                  128          Allocated PE                256            Used PV                     2          LV Name                     /dev/vg00/lvol12    LV Status                   available/syncd              LV Size (Mbytes)            4096               Current LE                  256          Allocated PE                512            Used PV                     2          --- Physical volumes ---    PV Name                     /dev/disk/disk2_p2    PV Status                   available                   Total PE                    4319       Free PE                     1188       Autoswitch                  On           Proactive Polling           On                  PV Name                     /dev/disk/disk3_p2    PV Status                   available                   Total PE                    4319       Free PE                     1188       Autoswitch                  On           Proactive Polling           On

The primary disk is disk2_p2 and the alternate disk is disk3_p2. In this example, the current size of lvol3 is 256 PE or 2048 MB.

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |   LVOL3   |      |   LVOL3   | +-----------+      +-----------+ |   LVOL4   |      |   LVOL4   | +-----------+      +-----------+ |   LVOL5   |      |   LVOL5   | +-----------+      +-----------+ |   LVOL6   |      |   LVOL6   | +-----------+      +-----------+ |   LVOL7   |      |   LVOL7   | +-----------+      +-----------+ |   LVOL8   |      |   LVOL8   | +-----------+      +-----------+ |   LVOL9   |      |   LVOL9   | +-----------+      +-----------+ |   LVOL10  |      |   LVOL10  | +-----------+      +-----------+ |   LVOL11  |      |   LVOL11  | +-----------+      +-----------+ |   LVOL12  |      |   LVOL12  | +-----------+      +-----------+

3.   Remove all mirrors from alternate disk down to lvol4.

# lvreduce -m 0 /dev/vg00/lvol12 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol11 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol10 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol9 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol8 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol7 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol6 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol5 /dev/disk/disk3_p2 # lvreduce -m 0 /dev/vg00/lvol4 /dev/disk/disk3_p2

boxnet:/root#vgdisplay -v vg00 --- Volume groups --- VG Name                     /dev/vg00 VG Write Access             read/write     VG Status                   available                 Max LV                      255    Cur LV                      12     Open LV                     12     Max PV                      16     Cur PV                      2      Act PV                      2      Max PE per PV               4329         VGDA                        4   PE Size (Mbytes)            16              Total PE                    8638    Alloc PE                    3899    Free PE                     4739    Total PVG                   0        Total Spare PVs             0              Total Spare PVs in use      0                     VG Version                  1.0       VG Max Size                 1108224m   VG Max Extents              69264            --- Logical volumes ---    LV Name                     /dev/vg00/lvol1    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                256            Used PV                     2          LV Name                     /dev/vg00/lvol2    LV Status                   available/syncd              LV Size (Mbytes)            8192               Current LE                  512          Allocated PE                1024           Used PV                     2          LV Name                     /dev/vg00/lvol3    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                256             Used PV                     2          LV Name                     /dev/vg00/lvol4    LV Status                   available/syncd              LV Size (Mbytes)            1024               Current LE                  64           Allocated PE                64             Used PV                     1          LV Name                     /dev/vg00/lvol5    LV Status                   available/syncd              LV Size (Mbytes)            9136               Current LE                  571          Allocated PE                571            Used PV                     1          LV Name                     /dev/vg00/lvol6    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                128            Used PV                     1          LV Name                     /dev/vg00/lvol7    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                128            Used PV                     1          LV Name                     /dev/vg00/lvol8    LV Status                   available/syncd              LV Size (Mbytes)            1024               Current LE                  64           Allocated PE                64             Used PV                     1          LV Name                     /dev/vg00/lvol9    LV Status                   available/syncd              LV Size (Mbytes)            8192               Current LE                  512          Allocated PE                512            Used PV                     1          LV Name                     /dev/vg00/lvol10    LV Status                   available/syncd              LV Size (Mbytes)            8192               Current LE                  512          Allocated PE                512            Used PV                     1          LV Name                     /dev/vg00/lvol11    LV Status                   available/syncd              LV Size (Mbytes)            2048               Current LE                  128          Allocated PE                128             Used PV                     1          LV Name                     /dev/vg00/lvol12    LV Status                   available/syncd              LV Size (Mbytes)            4096               Current LE                  256          Allocated PE                256            Used PV                     1          --- Physical volumes ---    PV Name                     /dev/disk/disk2_p2    PV Status                   available                   Total PE                    4319       Free PE                     1188       Autoswitch                  On           Proactive Polling           On                  PV Name                     /dev/disk/disk3_p2    PV Status                   available                   Total PE                    4319       Free PE                     3551       Autoswitch                  On           Proactive Polling           On

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |   LVOL3   |      |   LVOL3   | +-----------+      +-----------+ |   LVOL4   |      +-----------+      |   LVOL5   |      +-----------+      |   LVOL6   |      +-----------+      |   LVOL7   |      +-----------+      |   LVOL8   |      +-----------+      |   LVOL9   |      +-----------+      |   LVOL10  |      +-----------+      |   LVOL11  |      +-----------+       |   LVOL12  |      +-----------+

4.   At this point, the alternate disk is only mirroring lvol1, lvol2 and lvol3. You can confirm using pvdisplay -v /dev/disk/disk3_p2. Create a "step stone" logical volume in the alternate disk of the size you need to add to lvol3.

# lvcreate -n reserve /dev/vg00 # lvextend -l <PE_size> /dev/vg00/reserve /dev/disk/disk3_p2

boxnet:/root#pvdisplay -v /dev/disk/disk3_p2|more --- Physical volumes --- PV Name                     /dev/disk/disk3_p2 VG Name                     /dev/vg00 PV Status                   available                Allocatable                 yes          VGDA                        2   Cur LV                      3      PE Size (Mbytes)            16              Total PE                    4319    Free PE                     3551    Allocated PE                768         Stale PE                    0       IO Timeout (Seconds)        default             Autoswitch                  On        Proactive Polling           On                  --- Distribution of physical volume ---    LV Name                 LE of LV  PE for LV    /dev/vg00/lvol1         128       128          /dev/vg00/lvol2         512       512          /dev/vg00/lvol3         128       128

boxnet:/root#lvcreate -n reserve /dev/vg00 Logical volume "/dev/vg00/reserve" has been successfully created with character device "/dev/vg00/rreserve". Volume Group configuration for /dev/vg00 has been saved in /etc/lvmconf/vg00.conf # lvextend -L 2048 /dev/vg00/reserve /dev/disk/disk3_p2 boxnet:/root#lvextend -L 2048 /dev/vg00/reserve /dev/disk/disk3_p2 Logical volume "/dev/vg00/reserve" has been successfully extended. Volume Group configuration for /dev/vg00 has been saved in /etc/lvmconf/vg00.conf

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |   LVOL3   |      |   LVOL3   | +-----------+      +-----------+ |   LVOL4   |      |   Reserve | +-----------+      +-----------+ |   LVOL5   |     +-----------+     |   LVOL6   |     +-----------+     |   LVOL7   |     +-----------+     |   LVOL8   |     +-----------+     |   LVOL9   |     +-----------+     |   LVOL10  |     +-----------+     |   LVOL11  |     +-----------+     |   LVOL12  |     +-----------+

5.   Re-mirror the lvols to the alternate disk

# lvextend -m 1 /dev/vg00/lvol4 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol5 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol6 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol7 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol8 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol9 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol10 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol11 /dev/disk/disk3_p2 # lvextend -m 1 /dev/vg00/lvol12 /dev/disk/disk3_p2

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |   LVOL3   |      |   LVOL3   | +-----------+      +-----------+ |   LVOL4   |      |  reserve  | +-----------+      +-----------+ |   LVOL5   |      |   LVOL4   | +-----------+      +-----------+ |   LVOL6   |      |   LVOL5   | +-----------+      +-----------+ |   LVOL7   |      |   LVOL6   | +-----------+      +-----------+ |   LVOL8   |      |   LVOL7   | +-----------+      +-----------+ |   LVOL9   |      |   LVOL8   | +-----------+      +-----------+ |   LVOL10  |      |   LVOL9   | +-----------+      +-----------+ |   LVOL11  |      |   LVOL10  | +-----------+      +-----------+ |   LVOL12  |      |   LVOL11  | +-----------+      +-----------+                     |   LVOL12  |                    +-----------+

6.   Reduce the mirrors from the primary disk down to lvol4 included.

# lvreduce -m 0 /dev/vg00/lvol12 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol11 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol10 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol9 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol8 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol7 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol6 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol5 /dev/disk/disk2_p2 # lvreduce -m 0 /dev/vg00/lvol4 /dev/disk/disk2_p2

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |   LVOL3   |      |   LVOL3   | +-----------+      +-----------+                    |  RESERVE  |                    |           |                    +-----------+                    |   LVOL4   |                    +-----------+                    |   LVOL5   |                    +-----------+                    |   LVOL6   |                    +-----------+                    |   LVOL7   |                    +-----------+                    |   LVOL8   |                    +-----------+                    |   LVOL9   |                    +-----------+                    |   LVOL10  |                    +-----------+                    |   LVOL11  |                    +-----------+                    |   LVOL12  |                    +-----------+

7.   Remove the "step stone" lvol in the alternate disk to free its space.

# lvremove /dev/vg00/reserve boxnet:/tmp#lvremove /dev/vg00/reserve The logical volume "/dev/vg00/reserve" is not empty; do you really want to delete the logical volume (y/n) : y Logical volume "/dev/vg00/reserve" has been successfully removed. Volume Group configuration for /dev/vg00 has been saved in /etc/lvmconf/vg00.conf

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |   LVOL3   |      |   LVOL3   | +-----------+      +-----------+                    |  free...  |                    |           |                    +-----------+                    |   LVOL4   |                    +-----------+                    |   LVOL5   |                    +-----------+                    |   LVOL6   |                    +-----------+                    |   LVOL7   |                    +-----------+                    |   LVOL8   |                    +-----------+                    |   LVOL9   |                    +-----------+                    |   LVOL10  |                    +-----------+                    |   LVOL11  |                    +-----------+                    |   LVOL12  |                    +-----------+

8.   Now enough contiguous space is available in both drives to extend the /dev/vg00/lvol3 logical volume.

Extend the logical volume. This will increase lvol3 in both disks since the mirror hasn't been broken.

# lvextend -l <PE_size> /dev/vg00/lvol3 boxnet:/tmp#lvextend -L 4096 /dev/vg00/lvol3 Logical volume "/dev/vg00/lvol3" has been successfully extended. Volume Group configuration for /dev/vg00 has been saved in /etc/lvmconf/vg00.conf

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |           |      |           | |   LVOL3   |      |   LVOL3   | |           |      |           | |           |      |           | +-----------+      +-----------+                    |   LVOL4   |                    +-----------+                    |   LVOL5   |                    +-----------+                    |   LVOL6   |                    +-----------+                    |   LVOL7   |                    +-----------+                    |   LVOL8   |                    +-----------+                    |   LVOL9   |                    +-----------+                    |   LVOL10  |                    +-----------+                    |   LVOL11  |                    +-----------+                    |   LVOL12  |                    +-----------+

9.   Re-mirror the lvols from the alternate disk to the primary disk.

# lvextend -m 1 /dev/vg00/lvol12 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol11 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol10 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol9 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol8 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol7 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol6 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol5 /dev/disk/disk2_p2 # lvextend -m 1 /dev/vg00/lvol4 /dev/disk/disk2_p2

CURRENT DISK CONFIGURATION PRIMARY DISK       ALTERNATE DISK +-----------+      +-----------+ |   LVOL1   |      |   LVOL1   | +-----------+      +-----------+ |   LVOL2   |      |   LVOL2   | +-----------+      +-----------+ |           |      |           | |   LVOL3   |      |   LVOL3   | |           |      |           | |           |      |           | +-----------+      +-----------+ |   LVOL4   |      |   LVOL4   | +-----------+      +-----------+ |   LVOL5   |      |   LVOL5   | +-----------+      +-----------+ |   LVOL6   |      |   LVOL6   | +-----------+      +-----------+ |   LVOL7   |      |   LVOL7   | +-----------+      +-----------+ |   LVOL8   |      |   LVOL8   | +-----------+      +-----------+ |   LVOL9   |      |   LVOL9   | +-----------+      +-----------+ |   LVOL10  |      |   LVOL10  | +-----------+      +-----------+ |   LVOL11  |      |   LVOL11  | +-----------+      +-----------+ |   LVOL12  |      |   LVOL12  | +-----------+      +-----------+

10.  Extend the filesystem of lvol3 using OnlineJFS fsadm command.

# fsadm -F vxfs -b <Current PEs * PE_size>M / boxnet:/tmp#fsadm -F vxfs -b 4096m / UX:vxfs fsadm: INFO: V-3-25942: /dev/vg00/rlvol3 size increased from 2097152 sectors to 4194304 sectors

11.  Final Size of root File System that is extended by 2 GB.

boxnet:/tmp#bdf / Filesystem          kbytes    used   avail %used Mounted on /dev/vg00/lvol3    4194304  289344 3874512    7% /

12.  Take a Reboot after completing this activity, to re-confirm everything is fine.