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GRAID3(8)		  BSD System Manager's Manual		     GRAID3(8)

     graid3 -- control utility for RAID3 devices

     graid3 label [-hnrvw] name	prov prov prov [prov [...]]
     graid3 clear [-v] prov [prov [...]]
     graid3 configure [-adhnrRvwW] name
     graid3 rebuild [-v] name prov
     graid3 insert [-hv] -n number name	prov
     graid3 remove [-v]	-n number name
     graid3 stop [-fv] name [name [...]]
     graid3 list [name [...]]
     graid3 load [-v]
     graid3 unload [-v]

     The graid3	utility	is used	for RAID3 arrays configuration.	 After a de-
     vice creation, all	components are detected	and configured automatically.
     All operations like failure detection, stale components detection,	re-
     build of stale components etc. are	done automatically as well.  The
     graid3 utility uses on-disk metadata (the last provider's sector) to
     store all needed information.

     The first argument	to graid3 indicates an action to be performed:

     label	Create a RAID3 device.	The last given component will contain
		parity data, all the rest - regular data.  Number of compo-
		nents has to be	equal to 3, 5, 9, 17, etc. (2^n	+ 1).

		Additional options include:

		-h  Hardcode providers'	names in metadata.

		-n  Turn off autosynchronization of stale components.

		-r  Use	parity component for reading in	round-robin fashion.
		    Without this option	parity component is not	used at	all
		    for	reading	operations when	device is in complete state.
		    With this option specified random I/O read operations are
		    even 40% faster, but sequential reads are slower.  One
		    cannot not use this	options	if -w option is	also speci-

		-w  Use	verify reading feature.	 When reading from device in
		    complete state, read data also from	parity component and
		    verify the data by comparing XORed regular data with par-
		    ity	data.  If verification fails, EIO error	is returned
		    and	value of sysctl	kern.geom.raid3.stat.parity_mismatch
		    is increased.  One cannot not use this options if -r op-
		    tion is also specified.

     clear	Clear metadata on the given providers.

     configure	Configure the given device.

		Additional options include:

		-a  Turn on autosynchronization	of stale components.

		-d  Do not hardcode providers' names in	metadata.

		-h  Hardcode providers'	names in metadata.

		-n  Turn off autosynchronization of stale components.

		-r  Turn on round-robin	reading.

		-R  Turn off round-robin reading.

		-w  Turn on verify reading.

		-W  Turn off verify reading.

     rebuild	Rebuild	the given component forcibly.  If autosynchronization
		wasn't turn off	for the	given device, this command hopefully
		will not be used.

     insert	Add the	given component	to the existing	array, if one of the
		component was removed previously with the remove command or
		one component is missing and will not be connected again.

		Additional options include:

		-h  Hardcode providers'	names in metadata.

     remove	Remove the given component from	the given array	and clear
		metadata on it.

     stop	Stop the given arrays.

		Additional options include:

		-f  Stop the given array even if it is opened.

     list	List every currently configured	devices, if a list of devices
		is passed as a parameter then only those devices will be

     load	Load geom_raid3.ko kernel module.

     unload	Unload geom_raid3.ko kernel module.

     Additional	options	include:

     -v	 Be more verbose.

     Use 3 disks to setup a RAID3 array	(use round-robin reading feature).
     Create a file system, mount it, then unmount it and stop device:

	   graid3 label	-v -r data da0 da1 da2
	   newfs /dev/raid3/data
	   mount /dev/raid3/data /mnt
	   umount /mnt
	   graid3 stop data
	   graid3 unload

     Create a RAID3 array, but do not use automatic sunchronization feature.
     Rebuild parity component:

	   graid3 label	-n data	da0 da1	da2
	   graid3 rebuild data da2

     Replace one data disk with	a brand	new one:

	   graid3 remove -n 0 data
	   graid3 insert -n 0 data da5

     Exit status is 0 on success, and 1	if the command fails.

     geom(4), geom(8), mount(8), newfs(8), umount(8), vinum(8)

     The graid3	utility	appeared in FreeBSD 5.3.

     Pawel Jakub Dawidek <>

     There should be a section with implementation description.

BSD				 Aug 22, 2004				   BSD


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