Commands for Copying File Systems
When you need to back up and restore complete file systems, use
the ufsdump and ufsrestore commands described in Chapter 28, UFS Backup and Restore Commands (Reference). When you want to
copy or move individual files, portions of file systems, or complete file systems,
you can use the procedures described in this chapter instead of the ufsdump
and ufsrestore commands.
The following table describes when to use the various backup commands.
Table 29-1 When to Use Various Backup Commands
The following table describes various backup and restore commands.
Table 29-2 Summary of Various Backup Commands
Command Name |
Aware of File
System Boundaries? |
Supports Multiple Volume Backups? |
Physical or Logical Copy? |
|---|
volcopy |
Yes |
Yes |
Physical |
tar |
No |
No |
Logical |
cpio |
No |
Yes |
Logical |
pax |
Yes |
Yes |
Logical |
dd |
Yes |
No |
Physical |
ufsdump/ufsrestore |
Yes |
Yes |
Logical |
fssnap |
N/A |
N/A |
Logical |
The following table describes the advantages and disadvantages of some of these commands.
Table 29-3 Advantages and Disadvantages of tar, pax, and cpio Commands
Command |
Function |
Advantages |
Disadvantages |
|---|
tar |
Use
to copy files and directory subtrees to a single tape. |
|
Is not aware of file system boundaries Length of full path name cannot exceed 255 characters Cannot be used to create multiple tape volumes
|
pax |
Use to copy
files, special files, or file systems that require multiple tape volumes. Or, use
when you want to copy files to and from POSIX-compliant systems. |
|
Same disadvantages as
the tar command, except that the pax command can create multiple tape volumes. |
cpio |
Use
to copy files, special files, or file systems that require multiple tape volumes.
Or, use when you want to copy files from systems running current Solaris
releases systems to systems running SunOS 4.0/4.1 releases. |
Packs data onto tape more efficiently than the tar command Skips over any bad spots in a tape when restoring Provides options for writing files with different header formats, such as ( tar, ustar, crc, odc, bar), for portability between different system types Creates multiple tape volumes
|
The command syntax is more
difficult than the tar or pax commands. |
The following sections describes step-by-step instructions and examples of how to use these
commands.
