Unix/Linux Go Back    

OpenSolaris 2009.06 - man page for md.cf (opensolaris section 4)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

md.tab(4)				   File Formats 				md.tab(4)

       md.tab, md.cf - Solaris Volume Manager utility files


       The  file  /etc/lvm/md.tab can be used by metainit(1M) and metadb(1M) to configure metade-
       vices, hot spare pools, and metadevice state  database  replicas  in  a	batch-like  mode.
       Solaris	Volume	Manager  does  not store configuration information in the /etc/lvm/md.tab
       file. You can use:

	 metastat -p > /etc/lvm/md.tab

       to create this file. Edit it by hand using the instructions in the  md.tab.4  file.  Simi-
       larly,  if  no  hot spares are in use, the cp md.cf md.tab command generates an acceptable
       version of the md.tab file, with the editing caveats previously mentioned.

       When using the md.tab file, each metadevice, hot spare pool, or state database replica  in
       the  file  must have a unique entry. Entries can include the following: simple metadevices
       (stripes, concatenations, and concatenations of stripes); mirrors,  soft  partitions,  and
       RAID5  metadevices;  hot spare pools; and state database replicas. Because md.tab contains
       only entries that you enter in it, do not rely on the file for the  current  configuration
       of metadevices, hot spare pools, and replicas on the system at any given time.

       Tabs,  spaces,  comments (by using a pound sign, #), and continuation of lines (by using a
       backslash-newline), are allowed.

       Typically, you set up metadevices according to information specified on the  command  line
       by  using  the  metainit  command.  Likewise,  you set up state database replicas with the
       metadb command.

       An alternative to the command line is to use the md.tab file. Metadevices and state  data-
       base  replicas  can  be specified in the md.tab file in any order, and then activated in a
       batch-like mode with the metainit and metadb commands.

       If you edit the md.tab file, you  specify  one  complete  configuration	entry  per  line.
       Metadevices  are  defined  using  the same syntax as required by the metainit command. You
       then run the metainit command with either the -a option, to activate  all  metadevices  in
       the  md.tab  file,  or  with the metadevice name corresponding to a specific configuration

       metainit does not maintain the state of the volumes that  would	have  been  created  when
       metainit is run with both the -a and -n flags. If a device d0 is created in the first line
       of the md.tab file, and a later line in md.tab assumes the existence of d0, the later line
       will fail when metainit -an runs (even if it would succeed with metainit -a).

       State  database	replicas  are defined in the /etc/lvm/md.tab file as follows: mddb number
       options [ slice... ] Where mddb number is the characters mddb followed by a number of  two
       or  more digits that identifies the state database replica. slice is a physical slice. For
       example: mddb05 /dev/dsk/c0t1d0s2. The file /etc/lvm/md.cf is a backup of  the  configura-
       tion  used  for	disaster  recovery. Whenever the Volume Manager configuration is changed,
       this file is automatically updated (except  when  hot  sparing  occurs).  You  should  not
       directly edit this file.

       Example 1 Concatenation

       All drives in the following examples have the same size of 525 Mbytes.

       This  example  shows  a	metadevice, /dev/md/dsk/d7, consisting of a concatenation of four

	 # (concatenation of four disks)
	 d7 4 1 c0t1d0s0 1 c0t2d0s0 1 c0t3d0s0 1 c0t4d0s0

       The number 4 indicates there are four individual stripes in the concatenation. Each stripe
       is  made  of  one  slice, hence the number 1 appears in front of each slice. Note that the
       first disk sector in all of the above devices contains  a  disk	label.	To  preserve  the
       labels	on  devices  /dev/dsk/c0t2d0s0,  /dev/dsk/c0t3d0s0,  and  /dev/dsk/c0t4d0s0,  the
       metadisk driver must skip at least the first sector of those disks when	mapping  accesses
       across  the concatenation boundaries. Since skipping only the first sector would create an
       irregular disk geometry, the entire first cylinder of these disks will  be  skipped.  This
       allows higher level file system software to optimize block allocations correctly.

       Example 2 Stripe

       This example shows a metadevice, /dev/md/dsk/d15, consisting of two slices.

	 # (stripe consisting of two disks)
	 d15 1 2 c0t1d0s2 c0t2d0s2 -i 32k

       The number 1 indicates that one stripe is being created. Because the stripe is made of two
       slices, the number 2 follows next. The optional -i followed by 32k specifies the interlace
       size will be 32 Kbytes. If the interlace size were not specified, the stripe would use the
       default value of 16 Kbytes.

       Example 3 Concatenation of Stripes

       This example shows a metadevice, /dev/md/dsk/d75, consisting of	a  concatenation  of  two
       stripes of three disks.

	 # (concatenation of two stripes, each consisting of three disks)
	 d75 2 3 c0t1d0s2 c0t2d0s2 c0t3d0s2 -i 16k \
	       3 c1t1d0s2 c1t2d0s2 c1t3d0s2 -i 32k

       On the first line, the -i followed by 16k specifies that the stripe's interlace size is 16
       Kbytes. The second set specifies the stripe interlace size will be 32 Kbytes. If the  sec-
       ond set did not specify 32 Kbytes, the set would use default interlace value of 16 Kbytes.
       The blocks of each set of three disks are interlaced across three disks.

       Example 4 Mirroring

       This example shows a three-way mirror, /dev/md/dsk/d50, consisting  of  three  submirrors.
       This mirror does not contain any existing data.

	 # (mirror)
	 d50 -m d51
	 d51 1 1 c0t1d0s2
	 d52 1 1 c0t2d0s2
	 d53 1 1 c0t3d0s2

       In this example, a one-way mirror is first defined using the -m option. The one-way mirror
       consists of submirror d51. The other two submirrors, d52 and d53, are attached later using
       the  metattach  command.  The  default read and write options in this example are a round-
       robin read algorithm and parallel writes to all submirrors. The	order  in  which  mirrors
       appear in the /etc/lvm/md.tab file is unimportant.

       Example 5 RAID5

       This example shows a RAID5 metadevice, d80, consisting of three slices:

	 # (RAID devices)
	 d80 -r c0t1d0s1 c1t0d0s1 c2t0d0s1 -i 20k

       In  this example, a RAID5 metadevice is defined using the -r option with an interlace size
       of 20 Kbytes. The data and parity segments will be striped across  the  slices,	c0t1d0s1,
       c1t0d0s1, and c2t0d0s1.

       Example 6 Soft Partition

       This  example  shows  a	soft  partition, d85, that reformats an entire 9 GB disk. Slice 0
       occupies all of the disk except for the few Mbytes  taken  by  slice  7,  which	is  space
       reserved  for a state database replica. Slice 7 will be a minimum of 4Mbytes, but could be
       larger, depending on the disk geometry. d85 sits on c3t4d0s0.

       Drives are repartitioned when they are added to a diskset only if Slice 7 is  not  set  up
       correctly. A small portion of each drive is reserved in Slice 7 for use by Volume Manager.
       The remainder of the space on each drive is placed into Slice 0. Any existing data on  the
       disks is lost after repartitioning. After adding a drive to a diskset, you can repartition
       the drive as necessary. However, Slice 7 should not be moved, removed, or overlapped  with
       any other partition.

       Manually  specifying  the  offsets and extents of soft partitions is not recommended. This
       example is included for to provide a better understanding of the file if it  is	automati-
       cally generated and for completeness.

	 # (Soft Partitions)
	 d85 -p -e c3t4d0 9g

       In  this  example,  creating  the soft partition and required space for the state database
       replica occupies all 9 GB of disk c3t4d0.

       Example 7 Soft Partition

       This example shows the command used to re-create a soft partition with  two  extents,  the
       first  one  starting  at offset 20483 and extending for 20480 blocks and the second extent
       starting at 135398 and extending for 20480 blocks:

	 # (Soft Partitions)
	 d1 -p c0t3d0s0 -o 20483 -b 20480 -o 135398 -b 20480

       Example 8 Hot Spare

       This example shows a three-way mirror, /dev/md/dsk/d10, consisting of three submirrors and
       three hot spare pools.

	 # (mirror and hot spare)
	 d10 -m d20
	 d20 1 1 c1t0d0s2 -h hsp001
	 d30 1 1 c2t0d0s2 -h hsp002
	 d40 1 1 c3t0d0s2 -h hsp003
	 hsp001 c2t2d0s2 c3t2d0s2 c1t2d0s2
	 hsp002 c3t2d0s2 c1t2d0s2 c2t2d0s2
	 hsp003 c1t2d0s2 c2t2d0s2 c3t2d0s2

       In this example, a one-way mirror is first defined using the -m option. The submirrors are
       attached later using the metattach(1M) command. The hot spare pools to be used are tied to
       the  submirrors	with  the  -h  option. In this example, there are three disks used as hot
       spares, defined in three separate hot spare pools. The hot spare pools are given the names
       hsp001,	hsp002,  and  hsp003. Setting up three hot spare pools rather than assigning just
       one hot spare with each component helps to maximize the use of hardware.  This  configura-
       tion  enables the user to specify that the most desirable hot spare be selected first, and
       improves availability by having more hot spares available. At the end of  the  entry,  the
       hot spares to be used are defined. Note that, when using the md.tab file, to associate hot
       spares with metadevices, the hot spare spool does not have to exist prior to the  associa-
       tion.  Volume Manager takes care of the order in which metadevices and hot spares are cre-
       ated when using the md.tab file.

       Example 9 State Database Replicas

       This example shows how to set up an initial state database and three replicas on a  server
       that has three disks.

	 # (state database and replicas)
	 mddb01 -c 3 c0t1d0s0 c0t2d0s0 c0t3d0s0

       In  this  example,  three  state database replicas are stored on each of the three slices.
       Once the above entry is made in the /etc/lvm/md.tab file, the metadb command must  be  run
       with  both  the	-a  and -f options. For example, typing the following command creates one
       state database replicas on three slices:

	 # metadb -a -f mddb01

	   o	  /etc/lvm/md.tab

	   o	  /etc/lvm/md.cf

       mdmonitord(1M),	metaclear(1M),	metadb(1M),  metadetach(1M),  metahs(1M),   metainit(1M),
       metaoffline(1M),  metaonline(1M),  metaparam(1M), metarecover(1M), metarename(1M), metare-
       place(1M), metaroot(1M), metassist(1M), metaset(1M),  metastat(1M),  metasync(1M),  metat-
       tach(1M), md.cf(4), mddb.cf(4), attributes(5), md(7D)

       Solaris Volume Manager Administration Guide

       Recursive  mirroring  is not allowed; that is, a mirror cannot appear in the definition of
       another mirror.

       Recursive logging is not allowed.

       Stripes and RAID5 metadevices must contains slices or soft partitions only.

       Mirroring of RAID5 metadevices is not allowed.

       Soft partitions can be built directly on slices or can be the  top  level  (accessible  by
       applications  directly),  but  cannot  be  in the middle, with other metadevices above and
       below them.

       Trans metadevices have been replaced by UFS logging. Existing trans devices are	not  log-
       ging--they pass data directly through to the underlying device. See mount_ufs(1M) for more
       information about UFS logging.

SunOS 5.11				   15 Dec 2004					md.tab(4)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 12:43 PM.