NAME

metattach, metadetach − attach or detach metadevice to or from a metamirror or metatrans

SYNOPSIS

/usr/opt/SUNWmd/sbin/metattach [−s setname ] [ −h ] metamirror metadevice
/usr/opt/SUNWmd/sbin/metattach [−s setname ] metatrans    metadevice|component
/usr/opt/SUNWmd/sbin/metattach [−s setname ] [ −i size ] metadevice    component...
/usr/opt/SUNWmd/sbin/metadetach [−s setname ] [ −f ] [ −h ] metamirror    submirror
/usr/opt/SUNWmd/sbin/metadetach [−s setname ] [ −f ] metatrans
/usr/opt/SUNWmd/sbin/metattach [−s setname ] RAID    component...

AVAILABILITY

These programs are available with the Solstice DiskSuite software package (SUNWmd). 

DESCRIPTION

metattach is used for adding submirrors to a metamirror, adding logging devices to metatrans devices, or growing metadevices and/or RAID devices.  Growing metadevices or RAID devices can be done without interrupting service.  To grow the size of a metamirror or metatrans, the components must be added to the submirrors or to the master or logging devices. 

The metadisk driver software supports one-to-three-way mirrors.  Thus, you can only attach a metadevice to a metamirror if there are two or fewer submirrors beneath the metamirror. 

Once a new metadevice is attached, metattach will automatically start a resync operation to the new submirror. 

Attaching a new logging device to a busy metatrans is allowed, although a metatrans will only start using its new logging device after the metatrans is idle (after it is unmounted, for example).  The busy metatrans will be in an Attaching state ( metastat(1M) ) until the logging device is actually attached.  Attaching a logging device in the Hard Error or Error state ( metastat(1M) ) is not allowed. 

metadetach detaches the metadevice from the metamirror.  Once detached, the metadevice is no longer part of the metamirror, thus reads and writes to and from the metadevice via the metamirror are no longer performed through the metamirror.  Detaching the only existing submirror is not allowed.  Detaching a submirror that has components reported as needing maintenance (by metastat(1M) ) is not allowed unless the −f (force) flag is used. 

metadetach also detaches the logging device from a metatrans.  Once detached, the logging device is no longer part of the metatrans, thus the metatrans is no longer logging and all benefits of logging are lost.  Any information on the logging device that pertains to the master device is written to the master device before the logging device is detached. 

Detaching the logging device from a busy metatrans device is not allowed unless the −f (force) flag is used.  Even so, the logging device is not actually detached until the metatrans is idle.  The metatrans is in the Detaching state ( metastat(1M) ) until the logging device is detached. 

OPTIONS

−i Specifies the interlace value for stripes.  Where size is a value specified in either kilobytes, megabytes, or blocks.  The interlace size number is followed by either “k” for kilobytes, “m” for megabytes, or “b” for blocks.   The units can be either upper case or lower case.  If size is not specified, the size defaults to the interlace size of the last stripe of the metadevice.  When an interlace size change is made on a stripe, it will be carried forward on all stripes that follow. 

−f Force detaching metadevices that have components that need maintenance or are busy. 

−h Display a help message. 

−s setname
Specifies the name of the diskset on which metattach or metadetach will work.  Using the −s option will cause the command to perform its administrative function within the specified diskset.  Without this option, the command will perform its function on your local metadevices. 

SEE ALSO

metaclear(1M), metadb(1M), metadetach(1M), metahs(1M), metainit(1M), metaoffline(1M), metaonline(1M), metaparam(1M), metareplace(1M), metaroot(1M), metaset(1M), metastat(1M), metasync(1M), md.tab(4), md.cf(4), mddb.cf(4)

Solstice DiskSuite Administration Guide

CAVEAT

When a submirror is detached from its metamirror, the data on the metadevice may not be the same as the data that existed on the metamirror prior to running metadetach.  In particular, if the -f option was needed to perform the detach, the metadevice probably does not contain the same data as the metamirror. 

SunOS DiskSuite_4.0  —  Last change: 03 February 1995