Chapter 23 Backing Up Files and File Systems (Tasks)

This chapter describes the procedures for backing up file systems by using the ufsdump command.

For information on these procedures, see Backing Up Files and File System (Task Map).

For overview information about performing backups, see Chapter 22, Backing Up and Restoring File Systems (Overview).

For detailed information on the ufsdump command syntax, options, and arguments, see Chapter 26, UFS Backup and Restore Commands (Reference).

Backing Up Files and File System (Task Map)

Preparing for File System Backups

The preparation for backing up file systems begins with planning, which is described in Chapter 22, Backing Up and Restoring File Systems (Overview) and includes choosing the following:

• The file systems to back up

• The type of backup (full or incremental) to perform

• A backup schedule

• A tape drive

For more information, see Chapter 22, Backing Up and Restoring File Systems (Overview).

This section describes two other tasks you might need to perform before you back up file systems:

• Finding the names of file systems to back up

• Determining the number of tapes that are needed for a full backup

How to Find File System Names

Steps

1. Display the contents of the /etc/vfstab file.

   $ more /etc/vfstab

2. Look in the mount point column for the name of the file system.

3. Use the directory name listed in the mount point column when you back up the file system.

Example 23–1 Finding File System Names

In this example, the file systems to be backed up are root (/), /usr, /datab, and /export/home.

$ more /etc/vfstab
#device           device             mount        FS   fsck mount   mount
#to mount         to fsck            point        type pass at boot options
#
fd                -                  /dev/fd      fd    -    no      -
/proc             -                  /proc        proc  -    no      -
/dev/dsk/c0t0d0s1 -                  -            swap  -    no      -
/dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 /            ufs   1    no      -
/dev/dsk/c0t0d0s6 /dev/rdsk/c0t0d0s6 /usr         ufs   1    no      -
/dev/dsk/c0t0d0s5 /dev/rdsk/c0t0d0s5 /datab       ufs   2    yes     -
/dev/dsk/c0t0d0s7 /dev/rdsk/c0t0d0s7 /export/home ufs   2    yes     -
swap              -                  /tmp         tmpfs -    yes     -

How to Determine the Number of Tapes Needed for a Full Backup

Steps

1. Become superuser or assume an equivalent role.

2. Estimate the size of the backup in bytes.

   # ufsdump S file-system

   The S option displays the estimated number of bytes that are needed to do the backup.

3. Divide the estimated size by the capacity of the tape to see how many tapes you need.

   For a list of tape capacities, see Table 22–5.

Example 23–2 Determining Number of Tapes

In this example, the file system of 489,472 bytes easily fits on a 150-Mbyte tape.

# ufsdump S /export/home
489472

Backing Up a File System

The following are general guidelines for performing backups:

• Use single-user mode or unmount the file system, unless you are creating a snapshot of a file system. For information about UFS snapshots, see Chapter 24, Using UFS Snapshots (Tasks).

• Be aware that backing up file systems when directory-level operations (such as creating, removing, and renaming files) and file-level activity are occurring simultaneously means that some data will not be included in the backup.

• You can run the ufsdump command from a single system and remotely back up groups of systems across the network through remote shell or remote login. In addition, you can direct the output to the system on which the tape device is located. Typically, the tape device is located on the system from which you run the ufsdump command, but it does not have to be.

  Another way to back up files to a remote device is to pipe the output from the ufsdump command to the dd command. For information about using the dd command, see Chapter 27, Copying UFS Files and File Systems (Tasks).

• If you are doing remote backups across the network, the system with the tape device must have entries in its /.rhosts file for each client that will be using the drive. Also, the system that initiates the backup must be included in the /.rhosts file on each system that it will back up.

• To specify a remote tape device on a system, use the naming convention that matches the OS release of the system with the remote tape device. For example, use the /dev/rst0 device for a remote device on a system that is running the SunOS 4.1.1 release or compatible versions. Use the /dev/rmt/0 device for a system running the Solaris 9 release or compatible versions.

Use the nisbackup command to back up an NIS+ master server. For information on using this command, see System Administration Guide: Naming and Directory Services (FNS and NIS+).

How to Backup a File System to Tape

The following are general steps for backing up file systems by using the ufsdump command. The examples show specific uses of options and arguments.

Steps

1. Become superuser or assume an equivalent role.

2. Bring the system to run level S (single-user mode).

   For example:

   # shutdown -g30 -y

3. (Optional) Check the file system for consistency.

   For example:

   # fsck -m /dev/rdsk/c0t0d0s7

   The fsck -m command checks for the consistency of file systems. For example, power failures can leave files in an inconsistent state. For more information on the fsck command, see Chapter 20, Checking UFS File System Consistency (Tasks).

4. If you need to back up file systems to a remote tape drive, follow these steps:

   1. On the system to which the tape drive is attached (the tape server), add the following entry to its /.rhosts file.

      host root

      The host entry specifies the name of the system on which you will run the ufsdump command to perform the backup.

   2. On the tape server, verify that the host added to the /.rhosts file is accessible through the name service.

5. Identify the device name of the tape drive.

   The default tape drive is the /dev/rmt/0 device.

6. Insert a tape that is write-enabled into the tape drive.

7. Back up file systems.

   # ufsdump options arguments filenames

   You can back up file systems or directories or files within file systems. For information on backing up individual files, see tar(1) or cpio(1).

   The following examples show how to use the most common ufsdump options and arguments:

   • Example 23–3

   • Example 23–4

   • Example 23–5

   • Example 23–6

   For other ufsdump options and arguments, see Chapter 26, UFS Backup and Restore Commands (Reference).

8. If prompted, remove the tape and insert the next tape volume.

9. Label each tape with the volume number, dump level, date, system name, disk slice, and file system.

10. Bring the system back to run level 3 by pressing Control-D.

11. Verify that the backup was successful.

    # ufsrestore tf device-name

Example 23–3 Performing a Full Backup of root (/)

The following example shows how to do a full backup of the root (/) file system. The system in this example is brought to single-user mode before the backup. The following ufsdump options are included:

• 0 specifies a 0 level dump (or a full backup).

• u specifies that the /etc/dumpdates file is updated with the date of this backup.

• c identifies a cartridge tape device.

• f /dev/rmt/0 identifies the tape device.

• / is the file system being backed up.

For example:

# init 0
ok boot -s
# ufsdump 0ucf /dev/rmt/0 /
  DUMP: Date of this level 0 dump: Tue Oct 07 16:23:08 2003
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t0d0s0 (starbug:/) to /dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Writing 63 Kilobyte records
  DUMP: Estimated 296644 blocks (144.85MB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: Tape rewinding
  DUMP: 296224 blocks (144.64MB) on 1 volume at 424 KB/sec
  DUMP: DUMP IS DONE
  DUMP: Level 0 dump on Tue Oct 07 16:23:08 2003
  # ufsrestore tf /dev/rmt/0
         2      .
         3      ./lost+found
      3776      ./usr
      7552      ./var
     11328      ./export
     15104      ./export/home
     18880      ./etc
     22656      ./etc/default
     22657      ./etc/default/sys-suspend
     22673      ./etc/default/cron
     22674      ./etc/default/devfsadm
     22675      ./etc/default/dhcpagent
     22676      ./etc/default/fs
     22677      ./etc/default/inetinit
     22678      ./etc/default/kbd
     22679      ./etc/default/mpathd
     22680      ./etc/default/nfslogd
     22681      ./etc/default/passwd
                .
                .
                .
  # (Press Control-D to bring system to run level 3)

Example 23–4 Performing an Incremental Backup of root (/)

The following example shows how to do an incremental backup of the root (/) file system in single-user mode. The following ufsdump options are included:

• 9 specifies a 9 level dump (or an incremental backup).

• u specifies that the /etc/dumpdates file is updated with the date of this backup.

• c identifies a cartridge tape device.

• f /dev/rmt/0 identifies the tape device.

• / is the file system being backed up.

# init 0
ok boot -s
.
.
.
Rebooting with command: boot -sSunOS Release 5.9  Generic May 2002
Copyright 1983-2003 Sun Microsystems, Inc.  All rights reserved.
.
.
.
# ufsdump 9ucf /dev/rmt/0 /
 DUMP: Date of this level 9 dump: Mon Oct 06 12:36:10 2003 
 DUMP: Date of last level 0 dump: Wed Oct 08 10:12:13 2003
 DUMP: Dumping /dev/rdsk/c0t0d0s0 (starbug:/) to /dev/rmt/0.
 DUMP: Mapping (Pass I) [regular files]
 DUMP: Mapping (Pass II) [directories]
 DUMP: Writing 63 Kilobyte records
 DUMP: Estimated 335844 blocks (163.99MB).
 DUMP: Dumping (Pass III) [directories]
 DUMP: Dumping (Pass IV) [regular files]
 DUMP: 335410 blocks (163.77MB) on 1 volume at 893 KB/sec
 DUMP: DUMP IS DONE
 DUMP: Level 9 dump on Mon Oct 06 12:36:10 2003
 # ufsrestore tf /dev/rmt/0
         2      .
         3      ./lost+found
      5696      ./usr
     11392      ./var
     17088      ./export
     22784      ./export/home
     28480      ./opt
      5697      ./etc
     11393      ./etc/default
     11394      ./etc/default/sys-suspend
     11429      ./etc/default/cron
     11430      ./etc/default/devfsadm
     11431      ./etc/default/dhcpagent
     11432      ./etc/default/fs
     11433      ./etc/default/inetinit
     11434      ./etc/default/kbd
     11435      ./etc/default/nfslogd
     11436      ./etc/default/passwd
     11437      ./etc/default/tar
                .
                .
                .

Example 23–5 Performing a Full Backup of a Home Directory

The following example shows how to do a full backup of the /export/home/kryten home directory. The following ufsdump options are included:

• 0 specifies that this is a 0 level dump (or a full backup)

• u specifies that the /etc/dumpdates file is updated with the date of this backup

• c identifies a cartridge tape device

• f /dev/rmt/0 identifies the tape device

• /export/home/kryten is the directory being backed up

# umount /export/home

# ufsdump 0ucf /dev/rmt/0 /export/home/kryten
  DUMP: Date of this level 0 dump: Tue Oct 07 08:41:41 2003
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t0d0s0 (starbug:/) to /dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Writing 63 Kilobyte records
  DUMP: Estimated 470 blocks (235KB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: 376 blocks (188KB) on 1 volume at 1205 KB/sec
  DUMP: DUMP IS DONE
# ufsrestore tf /dev/rmt/0
         2	    .
         5      ./export
         6      ./export/home
     80799      ./export/home/kryten
     80800      ./export/home/kryten/filea
     80801      ./export/home/kryten/fileb
     80802      ./export/home/kryten/filec
     80803      ./export/home/kryten/letters
     80804      ./export/home/kryten/letters/letter1
     80805      ./export/home/kryten/letters/letter2
     80806      ./export/home/kryten/letters/letter3
     80807      ./export/home/kryten/reports
     80808      ./export/home/kryten/reports/reportA
     80809      ./export/home/kryten/reports/reportB
     80810      ./export/home/kryten/reports/reportC
#

Example 23–6 Performing a Full Backup to a Remote System (Solaris 9 Data to Solaris 9 System)

The following example shows how to do a full backup of a local /export/home file system on a Solaris 9 system (starbug) to a tape device on a remote Solaris 9 system (earth) in single-user mode. The following ufsdump options are included:

• 0 specifies a 0 level dump (or a full backup).

• u specifies that the /etc/dumpdates file is updated with the date of this backup.

• c identifies a cartridge tape device.

• f earth:/dev/rmt/0 identifies the remote system name and tape device

• /export/home is the file system being backed up.

# ufsdump 0ucf earth:/dev/rmt/0 /export/home
  DUMP: Date of this level 0 dump: Mon Oct 06 12:46:50 2003
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/rdsk/c0t0d0s7 (starbug:/export/home) to 
  earth:/dev/rmt/0.
  DUMP: Mapping (Pass I) [regular files]
  DUMP: Mapping (Pass II) [directories]
  DUMP: Writing 63 Kilobyte records
  DUMP: Estimated 410 blocks (205KB).
  DUMP: Dumping (Pass III) [directories]
  DUMP: Dumping (Pass IV) [regular files]
  DUMP: Tape rewinding
  DUMP: 376 blocks (188KB) on 1 volume at 546 KB/sec
  DUMP: DUMP IS DONE
  DUMP: Level 0 dump on Mon Oct 06 12:46:50 2003
 # ufsrestore tf earth:/dev/rmt/0
          2      .
         3      ./lost+found
         4      ./kryten
         5      ./kryten/filea
         6      ./kryten/fileb
         7      ./kryten/filec
         8      ./kryten/letters
         9      ./kryten/letters/letter1
        10      ./kryten/letters/letter2
        11      ./kryten/letters/letter3
        12      ./kryten/reports
.
.
.
 #