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

NAME
     graid3 -- control utility for RAID3 devices

SYNOPSIS
     graid3 label [-hnrvw] name prov prov prov ...
     graid3 clear [-v] 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 ...
     graid3 list
     graid3 status
     graid3 load
     graid3 unload

DESCRIPTION
     The graid3 utility is used for RAID3 array configuration.  After a device
     is created, all components are detected and configured automatically.
     All operations such as failure detection, stale component detection,
     rebuild of stale components, etc. are also done automatically.  The
     graid3 utility uses on-disk metadata (the provider's last 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, whilst the others will all contain regular data.
                The number of components must 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 the parity component is not used at
                    all for reading operations when the device is in a com-
                    plete state.  With this option specified random I/O read
                    operations are even 40% faster, but sequential reads are
                    slower.  One cannot use this option if the -w option is
                    also specified.

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

     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
                was not turned off for the given device, this command should
                be unnecessary.

     insert     Add the given component to the existing array, if one of the
                components was removed previously with the remove command or
                if 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       See geom(8).

     status     See geom(8).

     load       See geom(8).

     unload     See geom(8).

     Additional options include:

     -v  Be more verbose.

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

EXAMPLES
     Use 3 disks to setup a RAID3 array (with the round-robin reading fea-
     ture).  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 the automatic synchronization fea-
     ture.  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

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

HISTORY
     The graid3 utility appeared in FreeBSD 5.3.

AUTHORS
     Pawel Jakub Dawidek <pjdATFreeBSD.org>

BUGS
     There should be a section with an implementation description.

     Documentation for sysctls kern.geom.raid3.* is missing.

BSD                             August 22, 2004                            BSD