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MKSNAP_FFS(8)		     System Manager's Manual		   MKSNAP_FFS(8)

NAME
     mksnap_ffs -- take a file system snapshot

SYNOPSIS
     mksnap_ffs snapshot_name

DESCRIPTION
     The  mksnap_ffs  utility creates a snapshot named snapshot_name.  This name
     is a path in the file system to be snapshotted.  Typically  this  is  under
     the  .snap directory in the root of the file system, but it can be anywhere
     in the filesystem being snapshotted.  Snapshots can  be  listed  using  the
     snapinfo(8) command.

     After  a  snapshot is taken it appears as a file.	The size of the snapshot
     file is equal to the size of the file system from which it was  taken.   It
     can be moved, renamed or deleted (which removes the snapshot).

     The group ownership of the file is set to "operator"; the owner of the file
     remains  "root".	The  mode  of  the snapshot is set to be readable by the
     owner or members of the "operator" group.

EXAMPLES
     Create a snapshot of /home file system and mount the snapshot elsewhere:

	   mksnap_ffs /home/.snap/snap1
	   mdconfig -a -t vnode -o readonly -f /home/.snap/snap1
	   mount -o ro /dev/md0 /mnt/

     Delete a snapshot:

	   rm /home/.snap/snap1

SEE ALSO
     rm(1), chmod(2), chown(8), mdconfig(8), mount(8), snapinfo(8)

HISTORY
     The mksnap_ffs utility first appeared in FreeBSD 5.1.

CAVEATS
     The disk full situation is not handled gracefully and may lead to a  system
     panic when no free blocks are found.

     Every  filesystem can have only up to 20 active snapshots.  When this limit
     is reached, attempting to create more  snapshots  fails  with  ENOSPC,  and
     mksnap_ffs reports that it is "out of space".

FreeBSD 15.1			  May 22, 2023			   MKSNAP_FFS(8)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=mksnap_ffs&sektion=8&manpath=FreeBSD+15.1-RELEASE+and+Ports>

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