System Administration Commands                       metasync(1M)



NAME
     metasync - handle metadevice resync during reboot

SYNOPSIS
     /usr/sbin/metasync -h


     /usr/sbin/metasync [-s setname] [buffersize] metadevice


     /usr/sbin/metasync [-s setname] -r [buffersize]


     /usr/sbin/metasync -p metadevice


     /usr/sbin/metasync -c metadevice


DESCRIPTION
     The metasync command starts a resync operation on the speci-
     fied metadevice. All components that need to be resynced are
     resynced. If the system crashes during a  RAID5  initializa-
     tion,  or during a RAID5 resync, either an initialization or
     resync restarts when the system reboots.


     Applications are free to access a  metadevice  at  the  same
     time  that  it is being resynced by metasync. Also, metasync
     performs the copy operations from inside the  kernel,  which
     makes the utility more efficient.


     Use the -r option in boot scripts  to  resync  all  possible
     submirrors.

OPTIONS
     The following options are supported:

     -c metadevice    Cancels the resync that is in  progress  on
                      the  specified  metadevice. The resync will
                      be stopped at its current point and can  be
                      resumed  by  running the "metasync metadev-
                      ice" command. This option only  applies  to
                      RAID1 volumes.


     -h               Displays usage message.


     -p metadevice    Regenerates parity  information  for  RAID5
                      metadevices.



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System Administration Commands                       metasync(1M)



     -s setname       Specifies the name of the diskset on  which
                      metasync  will  work.  Using  the -s option
                      will  cause  the  command  to  perform  its
                      administrative  function  within the speci-
                      fied diskset. Without this option, the com-
                      mand  will  perform  its  function on local
                      metadevices.


     -r               Specifies that the metasync command  handle
                      special resync requirements during a system
                      reboot. metasync -r should only be  invoked
                      from the svc:/system/mdmonitor service. The
                      metasync command only resyncs  those  meta-
                      devices  that need to be resynced. metasync
                      schedules all the mirror resyncs  according
                      to their pass numbers.

                      To override the default  buffersize  value
                      used  by the svc:/system/mdmonitor service,
                      you can edit /etc/system to specify:

                        set mdmirror:mdresyncbufsz = 2048


                      so that resyncs occur as quickly as  possi-
                      ble.


OPERANDS
     buffersize    Specifies the size (number of  512-byte  disk
                    blocks)  of  the internal copy buffer for the
                    mirror resync.  The  size  defaults  to  1024
                    512-byte  disk blocks. It can be no more than
                    2048 blocks. For best  performance  (quickest
                    completion of the resync), 2048 blocks is the
                    recommended size.


EXIT STATUS
     The following exit values are returned:

     0     Successful completion.


     >0    An error occurred.


ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:




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System Administration Commands                       metasync(1M)



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Availability                 SUNWmdu                     
    


SEE ALSO
     mdmonitord(1M), metaclear(1M),  metadb(1M),  metadetach(1M),
     metahs(1M),  metainit(1M),  metaoffline(1M), metaonline(1M),
     metaparam(1M),       metarecover(1M),        metarename(1M),
     metareplace(1M),  metaroot(1M),  metaset(1M), metassist(1M),
     metastat(1M),    metattach(1M),     md.tab(4),     md.cf(4),
     mddb.cf(4), md.tab(4), attributes(5), md(7D)


NOTES
     The metasync service is managed by  the  service  management
     facility, smf(5), under the service identifier:

       svc:/system/mdmonitor




     Administrative actions on this service,  such  as  enabling,
     disabling,  or  requesting  restart,  can be performed using
     svcadm(1M). The service's status can be  queried  using  the
     svcs(1) command.


























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