Lets say I have SAN storage, and I have created a 70GB LUN and exposed it to Solaris, where it shows up as ‘c0t3d0′.

# format
Searching for disks...done

AVAILABLE DISK SELECTIONS:
       0. c0t2d0 
          /pci@0,0/pci1022,7450@2/pci1000,3060@3/sd@2,0
       1. c0t3d0 
          /pci@0,0/pci1022,7450@2/pci1000,3060@3/sd@3,0
Specify disk (enter its number):

Under Solaris, I have created a Zpool named ‘zdata’ using this LUN.

# zpool status
  pool: zdata
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        zdata       ONLINE       0     0     0
          c0t3d0    ONLINE       0     0     0

errors: No known data errors

Over time, I have completely used up the 70GB worth of space, and I need to grow my zpool.

bash-3.00# zfs list
NAME           USED  AVAIL  REFER  MOUNTPOINT
zdata         66.9G      0  25.5K  /export/zdata
zdata/centos  24.5K      0  24.5K  legacy
zdata/share   66.9G      0  66.9G  /export/zdata/share

Question: How do I do this without corrupting data?

Answer: If you are using the whole lun as your vdev in zpool and using EFI label, you can export zpool, relabel the luns (using the new capacity) and import that zpool. You should be able to see the increased size then.

Assuming that I have given the entire LUN to the zpool (and not a slice), then this procedure should work. That said, I would back up my data if possible just to be on the safe side:

Summary:

• # zpool export zdata
• # format

• choose c0t3d0
• autoconfigure
• partition
• modify
• all-free-hog - choose slice 0
• size zero on all other slices
• label
• quit

• # zpool import mypool
• # zpool status (check for errors)
• # zfs list (should reflect new size)

Actual:

# format
 Searching for disks...done

AVAILABLE DISK SELECTIONS:
 0. c0t2d0 
 /pci@0,0/pci1022,7450@2/pci1000,3060@3/sd@2,0
 1. c0t3d0 
 /pci@0,0/pci1022,7450@2/pci1000,3060@3/sd@3,0
 Specify disk (enter its number): 1
 selecting c0t3d0
 [disk formatted]

FORMAT MENU:
 disk       - select a disk
 type       - select (define) a disk type
 partition  - select (define) a partition table
 current    - describe the current disk
 format     - format and analyze the disk
 fdisk      - run the fdisk program
 repair     - repair a defective sector
 label      - write label to the disk
 analyze    - surface analysis
 defect     - defect list management
 backup     - search for backup labels
 verify     - read and display labels
 inquiry    - show vendor, product and revision
 volname    - set 8-character volume name
 !     - execute , then return
 quit
 format> type

AVAILABLE DRIVE TYPES:
 0. Auto configure
 1. other
 Specify disk type (enter its number)[1]: 0
 c0t3d0: configured with capacity of 68.37GB
 
 selecting c0t3d0
 [disk formatted]

 format> partition

PARTITION MENU:
 0      - change `0' partition
 1      - change `1' partition
 2      - change `2' partition
 3      - change `3' partition
 4      - change `4' partition
 5      - change `5' partition
 6      - change `6' partition
 select - select a predefined table
 modify - modify a predefined partition table
 name   - name the current table
 print  - display the current table
 label  - write partition map and label to the disk
 ! - execute , then return
 quit
 partition> modify
 Select partitioning base:
 0. Current partition table (default)
 1. All Free Hog
 Choose base (enter number) [0]? 1

Part      Tag    Flag     First Sector         Size         Last Sector
 0       root    wm                 0           0               0
 1       swap    wu                 0           0               0
 2 unassigned    wu                 0           0               0
 3 unassigned    wm                 0           0               0
 4 unassigned    wm                 0           0               0
 5 unassigned    wm                 0           0               0
 6        usr    wm                 0           0               0
 8   reserved    wu                 0           0               0

Do you wish to continue creating a new partition
 table based on above table[yes]? yes
 Free Hog partition[6]? 0
 Enter size of partition 1 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Enter size of partition 2 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Enter size of partition 3 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Enter size of partition 4 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Enter size of partition 5 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Enter size of partition 6 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Enter size of partition 7 [0b, 33e, 0mb, 0gb, 0tb]: 0
 Part      Tag    Flag     First Sector         Size         Last Sector
 0        usr    wm                34       68.36GB          143358318
 1 unassigned    wu                 0           0               0
 2 unassigned    wu                 0           0               0
 3 unassigned    wm                 0           0               0
 4 unassigned    wm                 0           0               0
 5 unassigned    wm                 0           0               0
 6 unassigned    wm                 0           0               0
 8   reserved    wu         143358319        8.00MB          143374702

Ready to label disk, continue? yes

partition> quit

FORMAT MENU:
 disk       - select a disk
 type       - select (define) a disk type
 partition  - select (define) a partition table
 current    - describe the current disk
 format     - format and analyze the disk
 fdisk      - run the fdisk program
 repair     - repair a defective sector
 label      - write label to the disk
 analyze    - surface analysis
 defect     - defect list management
 backup     - search for backup labels
 verify     - read and display labels
 inquiry    - show vendor, product and revision
 volname    - set 8-character volume name
 !     - execute , then return
 quit
 format> quit

Now I can re-import my zpool, and the additional space will be available to my filesystems.

# zpool import zdata
# zpool status
  pool: zdata
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        zdata       ONLINE       0     0     0
          c0t3d0    ONLINE       0     0     0

errors: No known data errors
# zfs list
NAME           USED  AVAIL  REFER  MOUNTPOINT
zdata         66.9G      0  25.5K  /export/zdata
zdata/centos  24.5K      0  24.5K  legacy
zdata/share   66.9G      0  66.9G  /export/zdata/share

If I had actually grown the underlying LUN, the additional space would have shown up here, and my existing data would be intact.

By the way, OpenSolaris now has the ability to detect and use space that is dynamically allocated to a LUN. This will eventually make its way into production Solaris.