Convert UFS To ZFS

This article will show you how to turn Solaris 10 from UFS to ZFS filesystem. Please do backup on existing UFS filesystem before start execute this procedure. Suppose we have a server with Solaris 10 x86 installed on first disk (c1t0d0) and has free second disk (c1t1d0). We will try to copy the filesystem to the second disk which will be formatted using ZFS filesystem.

bash-3.00# format
Searching for disks...done


AVAILABLE DISK SELECTIONS:
       0. c1t0d0 <DEFAULT cyl 2085 alt 2 hd 255 sec 63>
          /pci@0,0/pci1000,8000@14/sd@0,0
       1. c1t1d0 <DEFAULT cyl 2086 alt 2 hd 255 sec 63>
          /pci@0,0/pci1000,8000@14/sd@1,0
Specify disk (enter its number): ^D
bash-3.00#
bash-3.00# df -h
Filesystem             size   used  avail capacity  Mounted on
/dev/dsk/c1t0d0s0       12G   3.3G   8.4G    28%    /
/devices                 0K     0K     0K     0%    /devices
ctfs                     0K     0K     0K     0%    /system/contract
proc                     0K     0K     0K     0%    /proc
mnttab                   0K     0K     0K     0%    /etc/mnttab
swap                   4.9G   548K   4.9G     1%    /etc/svc/volatile
objfs                    0K     0K     0K     0%    /system/object
sharefs                  0K     0K     0K     0%    /etc/dfs/sharetab
/usr/lib/libc/libc_hwcap1.so.1
                        12G   3.3G   8.4G    28%    /lib/libc.so.1
fd                       0K     0K     0K     0%    /dev/fd
swap                   4.9G   748K   4.9G     1%    /tmp
swap                   4.9G    28K   4.9G     1%    /var/run
bash-3.00# 

We need to prepare the second disk before create new ZFS filesystem on top of it. We will use format command to setup the partition on the second disk. Here is the step by step guide to do that :

  1. Invoke format command as shown below :

    bash-3.00# format -e c1t1d0
    selecting c1t1d0
    [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
            save       - save new disk/partition definitions
            inquiry    - show vendor, product and revision
            scsi       - independent SCSI mode selects
            cache      - enable, disable or query SCSI disk cache
            volname    - set 8-character volume name
            !<cmd>     - execute <cmd>, then return
            quit
    format>
    
  2. Type p for display current partition table in the c1t1d0 disk. If c1t1d0 is brand new disk, probably you will see the message about fdisk command as shown below :

    format> p
    WARNING - This disk may be in use by an application that has
              modified the fdisk table. Ensure that this disk is
              not currently in use before proceeding to use fdisk.
    format>
    
  3. To continue create a new partition table, type fdisk command and answer y to accept the default partition table.

    format> fdisk
    No fdisk table exists. The default partition for the disk is:
    
      a 100% "SOLARIS System" partition
    
    Type "y" to accept the default partition,  otherwise type "n" to edit the
     partition table.
    y
    format>
    
  4. Type p to display the partition menu :

    format> p
    
    
    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
            7      - change `7' partition
            9      - change `9' 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
            !<cmd> - execute <cmd>, then return
            quit
    partition>
    
  5. Type p again to display current partition layout :

    partition> p
    Current partition table (original):
    Total disk cylinders available: 2085 + 2 (reserved cylinders)
    
    Part      Tag    Flag     Cylinders        Size            Blocks
      0 unassigned    wm       0               0         (0/0/0)           0
      1 unassigned    wm       0               0         (0/0/0)           0
      2     backup    wu       0 - 2084       15.97GB    (2085/0/0) 33495525
      3 unassigned    wm       0               0         (0/0/0)           0
      4 unassigned    wm       0               0         (0/0/0)           0
      5 unassigned    wm       0               0         (0/0/0)           0
      6 unassigned    wm       0               0         (0/0/0)           0
      7 unassigned    wm       0               0         (0/0/0)           0
      8       boot    wu       0 -    0        7.84MB    (1/0/0)       16065
      9 unassigned    wm       0               0         (0/0/0)           0
    
    partition>
    
  6. In this example I want to assign the whole disk space to partition #0 :

    partition> 0
    Part      Tag    Flag     Cylinders        Size            Blocks
      0 unassigned    wm       0               0         (0/0/0)           0
    
    Enter partition id tag[unassigned]: 
    Enter partition permission flags[wm]: 
    Enter new starting cyl[0]: 0
    Enter partition size[0b, 0c, 0e, 0.00mb, 0.00gb]: 2084c
    partition>
    partition> p
    Current partition table (unnamed):
    Total disk cylinders available: 2085 + 2 (reserved cylinders)
    
    Part      Tag    Flag     Cylinders        Size            Blocks
      0 unassigned    wm       0 - 2083       15.96GB    (2084/0/0) 33479460
      1 unassigned    wm       0               0         (0/0/0)           0
      2     backup    wu       0 - 2084       15.97GB    (2085/0/0) 33495525
      3 unassigned    wm       0               0         (0/0/0)           0
      4 unassigned    wm       0               0         (0/0/0)           0
      5 unassigned    wm       0               0         (0/0/0)           0
      6 unassigned    wm       0               0         (0/0/0)           0
      7 unassigned    wm       0               0         (0/0/0)           0
      8       boot    wu       0 -    0        7.84MB    (1/0/0)       16065
      9 unassigned    wm       0               0         (0/0/0)           0
    
    partition>
    
  7. The last thing to do is make the changes permanent by invoke label command :

    partition> label
    [0] SMI Label
    [1] EFI Label
    Specify Label type[0]: 0
    Ready to label disk, continue? yes
    
    partition> 
    
  8. Finish the step by type q twice as shown below :

    partition> q
    
    
    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
            save       - save new disk/partition definitions
            inquiry    - show vendor, product and revision
            scsi       - independent SCSI mode selects
            cache      - enable, disable or query SCSI disk cache
            volname    - set 8-character volume name
            !<cmd>     - execute <cmd>, then return
            quit
    format> q
    bash-3.00# 
    

Since the second disk already prepared, then we can continue to make the new ZFS pool called rpool. We will create zpool create to make the ZFS pool.

bash-3.00# zpool create -f rpool c1t1d0s0

If we get error about invalid vdev specification we can move on by add -f option :

bash-3.00# zpool create rpool c1t1d0s0
invalid vdev specification
use '-f' to override the following errors:
/dev/dsk/c1t1d0s0 overlaps with /dev/dsk/c1t1d0s8
bash-3.00# zpool create -f rpool c1t1d0s0
bash-3.00# 

We can use zpool status to check the new pool we just created :

bash-3.00# zpool list
NAME    SIZE   USED  AVAIL    CAP  HEALTH  ALTROOT
rpool  15.9G    94K  15.9G     0%  ONLINE  -
bash-3.00# zpool status
  pool: rpool
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          c1t1d0s0  ONLINE       0     0     0

errors: No known data errors
bash-3.00# 

To start copying the whole root partition into the new rpool, we will use Solaris 10 Live Upgrade feature. We will use lucreate to create ZFS boot environment inside the rpool. lucreate command will automatically copy the whole root partition into the new pool. It might take some time to finish depend on the size of root partition (it might hang on the Copying stage for a while).

bash-3.00# lucreate -n zfsBE -p rpool
Checking GRUB menu...
Analyzing system configuration.
No name for current boot environment.
INFORMATION: The current boot environment is not named - assigning name <c1t0d0s0>.
Current boot environment is named <c1t0d0s0>.
Creating initial configuration for primary boot environment <c1t0d0s0>.
The device </dev/dsk/c1t0d0s0> is not a root device for any boot environment; cannot get BE ID.
PBE configuration successful: PBE name <c1t0d0s0> PBE Boot Device </dev/dsk/c1t0d0s0>.
Comparing source boot environment <c1t0d0s0> file systems with the file 
system(s) you specified for the new boot environment. Determining which 
file systems should be in the new boot environment.
Updating boot environment description database on all BEs.
Updating system configuration files.
The device </dev/dsk/c1t1d0s0> is not a root device for any boot environment; cannot get BE ID.
Creating configuration for boot environment <zfsBE>.
Source boot environment is <c1t0d0s0>.
Creating boot environment <zfsBE>.
Creating file systems on boot environment <zfsBE>.
Creating <zfs> file system for </> in zone <global> on <rpool/ROOT/zfsBE>.
Populating file systems on boot environment <zfsBE>.
Checking selection integrity.
Integrity check OK.
Populating contents of mount point </>.
Copying.
Creating shared file system mount points.
Creating compare databases for boot environment <zfsBE>.
Creating compare database for file system </rpool/ROOT>.
Creating compare database for file system </>.
Updating compare databases on boot environment <zfsBE>.
Making boot environment <zfsBE> bootable.
Updating bootenv.rc on ABE <zfsBE>.
File </boot/grub/menu.lst> propagation successful
Copied GRUB menu from PBE to ABE
No entry for BE <zfsBE> in GRUB menu
Population of boot environment <zfsBE> successful.
Creation of boot environment <zfsBE> successful.
bash-3.00# 

To check the status of new boot environment we can use lustatus command :

bash-3.00# lustatus 
Boot Environment           Is       Active Active    Can    Copy      
Name                       Complete Now    On Reboot Delete Status    
-------------------------- -------- ------ --------- ------ ----------
c1t0d0s0                   yes      yes    yes       no     -         
zfsBE                      yes      no     no        yes    -         
bash-3.00# 

To make new boot environment (zfsBE) active we will use luactivate command as shown below :

bash-3.00# luactivate zfsBE
Generating boot-sign, partition and slice information for PBE <c1t0d0s0>
A Live Upgrade Sync operation will be performed on startup of boot environment <zfsBE>.

Generating boot-sign for ABE <zfsBE>
NOTE: File </etc/bootsign> not found in top level dataset for BE <zfsBE>
Generating partition and slice information for ABE <zfsBE>
Boot menu exists.
Generating multiboot menu entries for PBE.
Generating multiboot menu entries for ABE.
Disabling splashimage
Re-enabling splashimage
No more bootadm entries. Deletion of bootadm entries is complete.
GRUB menu default setting is unaffected
Done eliding bootadm entries.

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

The target boot environment has been activated. It will be used when you 
reboot. NOTE: You MUST NOT USE the reboot, halt, or uadmin commands. You 
MUST USE either the init or the shutdown command when you reboot. If you 
do not use either init or shutdown, the system will not boot using the 
target BE.

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

In case of a failure while booting to the target BE, the following process 
needs to be followed to fallback to the currently working boot environment:

1. Boot from the Solaris failsafe or boot in Single User mode from Solaris 
Install CD or Network.

2. Mount the Parent boot environment root slice to some directory (like 
/mnt). You can use the following command to mount:

     mount -Fufs /dev/dsk/c1t0d0s0 /mnt

3. Run <luactivate> utility with out any arguments from the Parent boot 
environment root slice, as shown below:

     /mnt/sbin/luactivate

4. luactivate, activates the previous working boot environment and 
indicates the result.

5. Exit Single User mode and reboot the machine.

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

Modifying boot archive service
Propagating findroot GRUB for menu conversion.
File </etc/lu/installgrub.findroot> propagation successful
File </etc/lu/stage1.findroot> propagation successful
File </etc/lu/stage2.findroot> propagation successful
File </etc/lu/GRUB_capability> propagation successful
Deleting stale GRUB loader from all BEs.
File </etc/lu/installgrub.latest> deletion successful
File </etc/lu/stage1.latest> deletion successful
File </etc/lu/stage2.latest> deletion successful
Activation of boot environment <zfsBE> successful.
bash-3.00# 

To last thing to do is install boot loader program on the master boot record of the c1t1d0s0 :

bash-3.00# installgrub -fm /boot/grub/stage1  /boot/grub/stage2 /dev/rdsk/c1t1d0s0

Then we need to reboot the server using init command :

bash-3.00# init 6
updating /platform/i86pc/boot_archive
propagating updated GRUB menu
Saving existing file </boot/grub/menu.lst> in top level dataset for BE <zfsBE> as <mount-point>//boot/grub/menu.lst.prev.
File </boot/grub/menu.lst> propagation successful
File </etc/lu/GRUB_backup_menu> propagation successful
File </etc/lu/menu.cksum> propagation successful
File </sbin/bootadm> propagation successful
bash-3.00# 

System will automatically boot from the second disk (c1t1d0) and use ZFS boot environment. Using df command we can easily identify that now the system run on ZFS file system.

# df -h
Filesystem             size   used  avail capacity  Mounted on
rpool/ROOT/zfsBE        16G   3.4G   6.7G    35%    /
/devices                 0K     0K     0K     0%    /devices
ctfs                     0K     0K     0K     0%    /system/contract
proc                     0K     0K     0K     0%    /proc
mnttab                   0K     0K     0K     0%    /etc/mnttab
swap                   4.3G   356K   4.3G     1%    /etc/svc/volatile
objfs                    0K     0K     0K     0%    /system/object
sharefs                  0K     0K     0K     0%    /etc/dfs/sharetab
/usr/lib/libc/libc_hwcap1.so.1
                        10G   3.4G   6.7G    35%    /lib/libc.so.1
fd                       0K     0K     0K     0%    /dev/fd
swap                   4.3G    40K   4.3G     1%    /tmp
swap                   4.3G    24K   4.3G     1%    /var/run
rpool                   16G    29K   6.7G     1%    /rpool
rpool/ROOT              16G    18K   6.7G     1%    /rpool/ROOT
# 
# zpool list
NAME    SIZE   USED  AVAIL    CAP  HEALTH  ALTROOT
rpool  15.9G  4.95G  10.9G    31%  ONLINE  -
# zfs list
NAME               USED  AVAIL  REFER  MOUNTPOINT
rpool             8.96G  6.67G  29.5K  /rpool
rpool/ROOT        3.45G  6.67G    18K  /rpool/ROOT
rpool/ROOT/zfsBE  3.45G  6.67G  3.45G  /
rpool/dump        1.50G  6.67G  1.50G  -
rpool/swap        4.01G  10.7G    16K  -
# zpool status
  pool: rpool
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          c1t1d0s0  ONLINE       0     0     0

errors: No known data errors
# 

We can delete the old UFS boot environment using ludelete command.

bash-3.00# lustatus
Boot Environment           Is       Active Active    Can    Copy      
Name                       Complete Now    On Reboot Delete Status    
-------------------------- -------- ------ --------- ------ ----------
c1t0d0s0                   yes      no     no        yes    -         
zfsBE                      yes      yes    yes       no     -         
bash-3.00#
bash-3.00# ludelete -f c1t0d0s0
System has findroot enabled GRUB
Updating GRUB menu default setting
Changing GRUB menu default setting to <0>
Saving existing file </boot/grub/menu.lst> in top level dataset for BE <zfsBE> as <mount-point>//boot/grub/menu.lst.prev.
File </etc/lu/GRUB_backup_menu> propagation successful
Successfully deleted entry from GRUB menu
Determining the devices to be marked free.
Updating boot environment configuration database.
Updating boot environment description database on all BEs.
Updating all boot environment configuration databases.
Boot environment <c1t0d0s0> deleted.
bash-3.00# 

Now we have unused disk #0, we can use it as mirror disk. We do it by attaching c1t0d0 to the existing rpool.

bash-3.00# format
Searching for disks...done


AVAILABLE DISK SELECTIONS:
       0. c1t0d0 <DEFAULT cyl 2085 alt 2 hd 255 sec 63>
          /pci@0,0/pci1000,8000@14/sd@0,0
       1. c1t1d0 <DEFAULT cyl 2085 alt 2 hd 255 sec 63>
          /pci@0,0/pci1000,8000@14/sd@1,0
Specify disk (enter its number): ^D
bash-3.00# zpool status
  pool: rpool
 state: ONLINE
 scrub: none requested
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          c1t1d0s0  ONLINE       0     0     0

errors: No known data errors
bash-3.00# 

But first we need to copy the partition layout of c1t1d0 to the c1t0d0 :

bash-3.00# prtvtoc /dev/rdsk/c1t1d0s2 | fmthard -s - /dev/rdsk/c1t0d0s2
fmthard: Partition 0 overlaps partition 8. Overlap is allowed
        only on partition on the full disk partition).
fmthard: Partition 8 overlaps partition 0. Overlap is allowed
        only on partition on the full disk partition).
fmthard:  New volume table of contents now in place.
bash-3.00# 

Then we can attach c1t0d0 to the rpool using the following command :

bash-3.00# zpool attach -f rpool c1t1d0s0 c1t0d0s0

Once attached to the rpool, system will syncronize the disk (in ZFS term it called resilvering process). Don’t reboot the system before resilvering process completed. We can monitor resilvering process using zfs status command :

bash-3.00# zpool status
  pool: rpool
 state: ONLINE
status: One or more devices is currently being resilvered.  The pool will
        continue to function, possibly in a degraded state.
action: Wait for the resilver to complete.
 scrub: resilver in progress for 0h3m, 9.23% done, 0h35m to go
config:

        NAME          STATE     READ WRITE CKSUM
        rpool         ONLINE       0     0     0
          mirror      ONLINE       0     0     0
            c1t1d0s0  ONLINE       0     0     0
            c1t0d0s0  ONLINE       0     0     0

errors: No known data errors
bash-3.00# 

It probably take a while to let resilvering process finish :

bash-3.00# zpool status
  pool: rpool
 state: ONLINE
 scrub: resilver completed after 0h13m with 0 errors on Sun Sep  1 11:58:52 2013
config:

        NAME          STATE     READ WRITE CKSUM
        rpool         ONLINE       0     0     0
          mirror      ONLINE       0     0     0
            c1t1d0s0  ONLINE       0     0     0
            c1t0d0s0  ONLINE       0     0     0

errors: No known data errors
bash-3.00# 

Last thing to do is to install boot loader on c1t0d0 :

bash-3.00# installgrub -fm /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c1t0d0s0

Migrate UFS To ZFS by Tedy Tirtawidjaja

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