Solaris backup and restore utilities

Updated 27 Jan 2000 Read time 5 min(s) 10 sec(s) (1544 views). Solaris

This article provides an overview of the native backup and restore utilities available within the Solaris operating system.

Overview of utilities

Backup Utilities
- /usr/lib/fs/ufs/ufsdump (linked to /usr/sbin/ufsdump)
- /usr/sbin/tar
- /bin/cpio
- /bin/dd
Restore Utilities
- /usr/lib/fs/ufs/ufsrestore (linked to /usr/sbin/ufsrestore)
- /usr/sbin/tar
- /bin/cpio
- /bin/dd
Tape Utility
- /bin/mt

Utility Summary

ufsdump
- performs backups of ufs filesystems
- performs backups of specified files
- able to span multiple tapes
- does not cross file systems
- able to perform backups to remove devices
ufsrestore
- able to restore interactively
- able to restore from remote devices
tar
- able to cross filesystems
- Can perform remote dumps and restores with compound commands
- no interactive mode
- does not support multiple tapes
- able to restore singular files
- able to update dump files.
cpio
- able to cross filesystems
- supports multiple tapes
dd
- very simple dump of file/device to another file/device
- does not support multiple tapes
- does not cross filesystems

Basic usage

ufsdump
- this example performs a full backup of c0t0d0s0 and updates the /etc/dumpdates file.
```
# ufsdump 0uf /dev/rmt/0cn /dev/rdsk/c0t0d0s0
```
- this example performs an incremental backup and updates /etc/dumpdates
```
# ufsdump 5uf /dev/rmt/0cn /dev/rdsk/c0t0d0s0
```
- thisexampleperformsafulldumptoaremotedevice
```
# ufsdump 0uf hostb:/dev/rmt/0cn /dev/rdsk/c0t0d0s0
```
  special notes: the remote system must have entries for the local host in the root's .rhosts file if dumping to a remote file, the remote file must already exist.
ufsrestore
- this example restores to the current directory
```
# ufsrestore xf /dev/rmt/0
```
- thisexamplewillstartufsrestore in interactive mode and restore to the current directory
```
# ufsrestore if /dev/rmt/0
```
- thisexampleisfromtheufsrestore man page. It dumps and restores on one command line
```
# ufsdump 0f - /dev/rdsk/c0t0d0s7 | (cd /home;ufsrestore xf -)
```
- this example skips to the 3rd dump on the tape and restores to the current directory
```
# ufsrestore sxf 3 /dev/rmt/0
```
tar
- this example creates a backup of /usr to tape
```
# tar cf /dev/rmt/0cn /usr
```
- this example creates a backup of /opt to file
```
# tar cf /tmp/opt.tar /opt
```
- this example extracts from tape
```
# tar xf /dev/rmt/0
```
- this example shows the contents of a tar archive from tape
```
# tar tvf /dev/rmt/0
```
- this example extracts the /etc/passwd and /etc/shadow files from an archive of /etc from tape
```
# tar xvf /dev/rmt/0 /etc/shadow /etc/passwd
```
cpio
- this example creates an archive to tape
```
# find . | cpio -ovt > /dev/rmt/0cn
```
- thisexamplelistsfilesfrom from tape
```
# cpio -civt < /dev/rmt/0
```
- this example extracts files from tape
```
# cpio -icv < /dev/rmt/0
```

this example dumps files to tape

# dd if=/dev/rdsk/c0t0d0s0 of=/dev/rmt/0cn

this example extracts files from tape

# dd if=/dev/rmt/0 of=/dev/rdsk/c0t0d0s0

mt
- this example rewinds a tape
```
# mt -f /dev/rmt/0 rew
```
- this example rewinds and ejects a tape
```
# mt -f /dev/rmt/0 rewoffl
```
- thisexampleretensions a tape (occasionally corrects i/o errors)
```
# mt -f /dev/rmt/0 retension
```

Documentation Resources

Useful man pages:
- ufsdump(1M)
- ufsrestore(1M)
- tar(1)
  - chroot(1M)
- cpio(1)
  - ls(1)
  - find(1)
- dd(1M)
- mt(1)
  - st(7D)
- archives(4)
Useful SunSolve SRDB's and InfoDoc's
- Primary Boot Disk Emergency Backup and Restore. Info Docs: 20812
- Moving filesystems and boot devices with ufsdump and ufsrestore. Info Docs: 17234
- ufsdump aborts with "SIGSEGV( ) ABORTING!". Symptoms and Resolutions: 10879
- Copying a filesystem using ufsdump w/o a tape drive. Info Docs: 14067
- Central Startup for Remote System Dumps. Info Docs: 20031
- ufsdump remotely not working, cannot connect to tape host. Symptoms and Resolutions: 19168
- Tape drive parameters in device name. Info Docs: 14066
- A ufsdump/ufsrestore tutorial. Info Docs: 21351
- How can you force tar to restore to a relative path? Info Docs: 18015
- how to back up the root partition using "cpio" command. Symptoms and Resolutions: 7031

Troubleshooting

all utilities
- i/o error
  - clean the tape drive
  - retension the tape ( mt -f /dev/rmt/? retension)
  - tape is bad
- ran dump and nothing is on the tape
  - ls -l /dev/rmt* look for any files that are very large and not links example: ufsdump 0f /dev/rmt0cn or ufsdump 0f /dev/rmt/ocn
ufsdump/ufsrestore
- accessingremote device fails
  - local host is not /.rhosts on the remote machine.
- Answering the set owner mode question
  - never answer yes It will set the owner of all restored files to root.
  - There is no method of keeping this question from being asked.
tar
- cd /tmp, did tar xvf and no files are there.
  - The archive was done with absolute pathing. Files were restored to their absolute path
- i cannot tar to /dev/diskette
  - stop /usr/sbin/vold
dd
- my filesystem was corrupt, did a newfs and restored from dd archive. Corruption is back.
  - dd operates on a block level, corruption was in the archive and put back on the filesystem.

Sample backup scheme

Always suggest usingufsdump andufsrestore
- daily backup scheme to local tape
  - Do full backup on Sunday
  - Do level 5 incremental backups the rest of the week
    - this will reduce restore time in the event of disaster recovery
    - a level 5 everyday will backup all data newer or modified since Sunday's full backup. Therefore restoring several days worth of incrementals is not nessesary.
Steps to take
- gather raw device info.Typicaly from /etc/vfstab. Sometimes customers will have filesystems that aremountedviarc script.
  - via /etc/vfstab
    - grep rdsk /etc/vfstab|grep -v "#"|awk '{print $2}'
  - via mount command
    - mount|grep dsk|awk '{print $1}'
      - ufsdump will translate the mount point to the raw device
- perform backups via a script or command line with the following basic syntax. It will perform a level 5 backup of each raw fs in /etc/vfstab, update the /etc/dumpdates file, and log the backups to /var/log/mmdddumplog file.
```
# for VOL in `grep rdsk /etc/vfstab|grep -v "#"|awk '{print $2}'`
> do
> echo "starting dump of $VOL" >> /var/log/`date +%m%d`dumplog
> ufsdump 5fu /dev/rmt/0cn $VOL >> /var/log/`date +%m%d`dumplog 2>&1
> echo >> /var/log/`date +%m%d`dumplog
> done
# mt rewoffl
```

Solaris cpio tar mt dd ufsdump Storage ufsrestore