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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 snap-
       shot 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 snap-
       shot).

       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 else-
       where:

	     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	14.3			 May 22, 2023			 MKSNAP_FFS(8)

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