04Command line

Command line

Often you don't want to click at all: automatic backups at fixed times, several drives at once, verification after the backup. Everything the interface can do also works from the command line.

• Back up
• Names
• Verify
• Restore
• Mount
• Password
• Reference

ABack up

Back up a drive to a file

C:\> SNAPSHOT C: X:\C-Drive.sna

backs up drive C: to the file X:\C-Drive.SNA. Several drives, one after another, to a server:

SNAPSHOT C: \\Server\Backups\C-Drive.sna
SNAPSHOT D: \\Server\Backups\D-Drive.sna
SNAPSHOT E: \\Server\Backups\E-Drive.sna

If data on different partitions depends on each other, all of them must be backed up at the same time using a shadow copy. To do this, chain the drives with +:

SNAPSHOT C:+D:+E: \\Server\Backups\$disk-Drive.sna

Partitions without a drive letter are addressed like this:

HD1:1

first partition on the first disk (HD2:1 is the first on the second disk, and so on)

HD1:*

all partitions on the first disk

HD X

all partitions on the disk where drive X: is located (version 1.43 and later)

HDWIN:*

all partitions on the disk from which the running Windows was started

As soon as more than one partition is backed up, $disk must be part of the file name.

Common switches

BNames

File names with date and computer name

Snapshot replaces these placeholders in the file name at startup:

SNAPSHOT C: $LABEL="Backup"\$computername-$disk-$weekday.sna

CVerify

Verify and repair

C:\> SNAPSHOT X:\Backup\c-drive.sna -T

checks an existing image for consistency. In batch files, a separate verification run is usually more practical than -T during the backup: that way you can tell "didn't work because the server was unavailable or the disk was full" apart from "wrote data that is incorrect".

--QuickCheck:test.sna quickly checks whether the image looks complete and error-free. It does not replace the test with -T.

If an image is damaged or parts are missing, it is worthless as a backup, because you never know which parts are affected. If you only need a few files from it, this may help:

C:\> SNAPSHOT X:\DefektesImage.SNA --repair:Y:\REPARIERT.SNA

It should be possible to mount the repaired image; after running CHKDSK at the latest, you can access part of the data. There is no guarantee that the content is correct. From version 1.46, --repair X:KAPUTT.SNA appends the repair data to the original instead of creating a new image.

DRestore

Restore a drive

C:\> SNAPSHOT X:\D-Drive.sna D:

writes the image back to drive D:. The same restrictions apply as for a restore via the interface.

EMount

Mount an image as a drive

C:\> SNAPSHOT X:\C-Drive.sna Z: -V

turns the image into virtual drive Z: and opens Explorer. -VM only mounts, without Explorer. For batch files there is -VQ without any dialog; Snapshot must then be called with start:

start Snapshot x:\image.sna Z: -vq
xcopy z:\Data c:\Data /E /H /K /O
Snapshot --unmount:Z

--unmount without a letter unmounts all mounted images (version 1.38 and later).

FPassword

Password and exclusions

Specify the password for encryption, restore and mount with -PW=. Otherwise Snapshot prompts for it when mounting and restoring. An empty -PW= creates an unencrypted backup, even if a default password is stored.

C:\> SNAPSHOT C: X:\Backup\c-drive.sna -PW=SuperSecret

From version 1.47, the password no longer has to appear in plain text in the batch file. A key file is generated once from the password, and it does not need to be kept secret:

C:\> SNAPSHOT -pwgen=Key.txt -pw=Geheim
C:\> SNAPSHOT C: x:\image-c.sna -pwuse=Key.txt

To restore or mount, you then need the original password.

Excluding files

PAGEFILE.SYS and HIBERFIL.SYS are always excluded. Specify additional paths separated by commas; subdirectories are included:

--exclude:\Temp,\Windows\Memory.dmp,\Windows\Minidump\*

Technically, only the content of these files is omitted; the directory entries remain. After a restore, the files are therefore present but contain random data. That is why Snapshot places SnapshotDeleteAfterRestore.BAT in the image; you should run it after the restore.

GReference

More options

SNAPSHOT --? prints the complete list. A selection: