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

       vbackup,	vcat, vftp, vmount, vnfs - back	up Unix	file systems to	Venti

       vbackup	[ -DVinv ] [ -M	mtpt ] [ -m host ] [ -s	secs ] [ -w n ]	disk [
       score ]

       vcat [ -z ] disk	| score	> disk

       vftp score | disk

       vmount [	-v ] addr mtpt

       vnfs [ -ELLRVir ] [ -a addr ] [ -b blocksize ] [	-c cachesize ] config

       These programs back up and restore standard  Unix  file	system	images
       stored  in Images stored	in venti are named by scores, which consist of
       a file system type followed by a	colon and forty	hexadecimal digits, as


       (The  hexadecimal  data is the SHA1 hash	of the Venti root block	repre-
       senting the file	system image.)

       These programs expect the environment variable $venti to	be set to  the
       network	address	 of  the Venti server to use (for example, yourhost or

       Vbackup copies the file system stored on	disk to	the Venti  server  and
       prints  the score for the newly-stored image.  The argument disk	should
       be a disk or disk partition device that would be	appropriate to pass to

       The optional argument score is the score	of a previous  backup  of  the
       disk  image.   If  score	 is given, vbackup will	not write to Venti any
       blocks that have	not changed since the previous backup.	This is	only a
       speed  optimization:  since the blocks are already stored on Venti they
       need not	be sent	to the Venti server again.

       The options to vbackup are:

       -D     Turn on debugging	output.

       -V     Trace interactions with Venti server.

       -m host
	      -M mtpt Set names	used to	construct the path in the  mount  com-
	      mand.  The default host is the name returned by sysname (see The
	      default mtpt is the place	where disk is currently	mounted.

       Set backup mount	point:
	      this name	is also	used in	the printed mount  command.   The  de-
	      fault is the name	returned by sysname (see

       -n     No-op mode: do not write any blocks to the server

       -i     Read  scores  incrementally  from	the previous backup as needed,
	      rather than prefetching them.

       -v     Print verbose output.

       -w n   Write parallelism: keep n	writes to the server in	progress at  a

       -s secs
	      Status  interval:	 every	secs  seconds,	print  a line tracking
	      progress of the backup.

       When vbackup finishes, it prints	a single line of the form

	      mount /host/yyyy/mmdd/mtpt score yyyy/mmdd/hhmm

       This line is a valid configuration line for vnfs	 (q.v.).   Mntpath  is
       the path	on which disk is currently mounted.

       Vcat  writes the	named disk image to standard output.  Unused file sys-
       tem blocks are printed zeroed regardless	of their actual	content.

       By default, vcat	will assume  that  its	standard  output  is  seekable
       (i.e.,  it  has been redirected to a file or disk) and seek over	unused
       blocks instead of writing to them.  The -z option causes	vcat  to  zero
       unused blocks instead.

       Vftp  presents  an interface to a physical or backed-up disk image.  It
       is used mainly for debugging.  Type help	at the vftp> prompt for	a list
       of commands.

       Vmount  mounts  the  NFS	service	at the network connection address onto
       mountpoint.  On most operating systems, vmount must be run by the  user
       root.   Because address is passed to the	host OS	kernel rather than in-
       terpreted by it must be only an IP address, not a full dial address.

       Vnfs serves, using the NFS version 3 protocol, one or more disk	images
       in  a  synthetic	 tree  defined by the configuration file config.  Vnfs
       serves both NFS mount protocol and NFS protocol RPCs at	addr  (default
       udp!*!nfs).  The	options	are:

       -E     Disable  `encrypted'  handles.  By default handles are encrypted
	      with a random key	to avoid leaking information about the backed-
	      up file systems.	If encryption is disabled, the NFS handles ex-
	      posed to the client may leak information about the  root	scores
	      of the disks as well as inode numbers.

       -L     Local service only: serve	only requests from the loopback	inter-
	      face (

       -LL    Local service only, with	paranoia:  serve  only	requests  from
	      loopback,	 and  only from	the first source port that sends a re-
	      quest.  This option is intended to be used  to  make  sure  that
	      once  the	 local	host  has  mounted the service,	no other local
	      users can	access it.

       -R     Print all	NFS and	NFS mount RPCs to standard error.

       -V     Print all	Venti transactions to standard error.

       -a addr
	      Serve requests on	addr (see above).

       -b blocksize
	      Set block	size used by the in-memory venti block cache.  Must be
	      as  large	as the maximum block size in any file system mentioned
	      in the configuration.

       -c cachesize
	      Set the number of	blocks stored by the in-memory venti cache.

       -i     Run in ``insecure'' mode,	allowing remote	root users to use  uid
	      and  gid	0 and read any file.  (Normally, remote	root is	mapped
	      to uid and gid -1	and has	no special permissions.)

       -r     Respond to all requests with a Sun RPC rejection.	 This is  use-
	      ful during debugging.

       Config  is  a  text  file  describing  the backup hierarchy for vnfs to
       serve.  Lines beginning with a sharp (#)	are ignored.  The rest of  the
       file is a sequence of commands, one per line.  The commands are:

       mount mtpt score	time
	      Add  the	file  system  with  the	given score to the tree	at the
	      mount point mtpt.	 The path to the mount point will  be  created
	      if necessary.  If	/dev/null is given as the score, an empty file
	      system is	mounted	at mtpt, excluding mtpt's contents from	 view.
	      Time  is the modification	time to	return for the directory mtpt,
	      either a decimal number of seconds since the epoch or  a	string
	      of  the  form  yyyy/mmdd/hhmm giving the year, month, day, hour,
	      and minute.  (Vnfs does not use the  modification	 time  of  the
	      root  in	order  to avoid	accessing every	mounted	file system on
	      common actions like ls -l	/dump/sys/2005.)

       allow ip[/mask]

       deny ip[/mask]
	      These two	commands define	access permissions  based  on  IP  ad-
	      dress.   The  optional  mask  can	be a decimal number (24) or an
	      equivalent IP mask (  Each	 request  is  filtered
	      through  the  rules listed in the	configuration file.  The first
	      rule that	matches	is used.  If  any  allow  or  deny  rules  are
	      given,  the default action is to reject the request.  In the ab-
	      sence of any rules, the default action  is  to  accept  all  re-

       Reading	the  special  file  /dump/+refreshconfig causes	vnfs to	reload
       config.	The read returns either	the string ok or an error message.

       Running	on  the	 server	 bob,  back  up	 the  file  system  stored  on
       /dev/da0s1a, which is mounted on	/home:

	      %	vbackup	/dev/da0s1a
	      mount /bob/2005/0510/home	ffs:0123456789abcdef...	2005/0510/0831

       Serve  that  backup  and	a few others in	a tree reminiscent of Plan 9's
       dump file system, but hide each day's contents of /tmp :

	      %	cat config
	      mount /bob/2005/0510 ffs:0123456789abcdef... 2005/0510/0829
	      mount /bob/2005/0510/home	ffs:0123456789abcdef...	2005/0510/0831
	      mount /bob/2005/0510/tmp /dev/null 1
	      mount /bob/2005/0511 ffs:0123456789abcdef... 2005/0511/0827
	      mount /bob/2005/0511/home	ffs:0123456789abcdef...	2005/0511/0828
	      mount /bob/2005/0511/tmp /dev/null 1
	      %	vnfs -b	16k -c 1k config

       Mount the backups on a client machine using vmount:

	      #	vmount yourserver /dump
	      #	ls /dump/bob/2005

       (Users of fancy shells may need to quote	the address argument.)



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