diff options
Diffstat (limited to 'mdadm.8')
| -rw-r--r-- | mdadm.8 | 72 |
1 files changed, 57 insertions, 15 deletions
@@ -1,5 +1,5 @@ .\" -*- nroff -*- -.TH MDADM 8 +.TH MDADM 8 "" v1.1.0 .SH NAME mdadm \- manage MD devices .I aka @@ -27,14 +27,16 @@ md devices, (striping), .B RAID1 (mirroring), -.B RAID4 +.BR RAID4 , +.BR RAID5 , and -.B RAID5. - -Recent kernels (2002) also support a mode known as .BR MULTIPATH . -.B mdadm -only provides limited support for MULTIPATH as yet. + +.B MULTIPATH is not a Software RAID mechanism, but does involve +multiple devices. For +.B MULTIPATH +each device is a path to one common physical storage device. + .B mdadm is a program that can be used to create, manage, and monitor @@ -186,6 +188,11 @@ will act as though the config file contained exactly and will read .B /proc/partitions to find a list of devices to scan. +If the word +.B none +is given for the config file, then +.I mdadm +will act as though the config file were empty. .TP .BR -s ", " --scan @@ -241,9 +248,8 @@ same as --parity Specify the number of active devices in the array. This, plus the number of spare devices (see below) must equal the number of .I component-devices -(including -.B missing -devices) that are listed on the command line. +(including "\fBmissing\fP" devices) +that are listed on the command line. .TP .BR -x ", " --spare-devices= @@ -278,6 +284,16 @@ don't have this minor number are excluded. If you create an array as /dev/md1, then all superblocks will contain the minor number 1, even if the array is later assembled as /dev/md2. +Giving the literal word "dev" for +.B --super-minor +will cause +.I mdadm +to use the minor number of the md device that is being assembled. +e.g. when assembling +.BR /dev/md0 , +.M --super-minor=dev +will look for super blocks with a minor number of 0. + .TP .BR -f ", " --force Assemble the array even if some superblocks appear out-of-date @@ -395,6 +411,18 @@ Give a delay in seconds. polls the md arrays and then waits this many seconds before polling again. The default is 60 seconds. +.TP +.BR -f ", " --daemonise +Tell +.B mdadm +to run as a background daemon if it decides to monitor anything. This +causes it to fork and run in the child, and to disconnect form the +terminal. The process id of the child is written to stdout. +This is useful with +.B --scan +which will only continue monitoring if a mail address or alert program +is found in the config file. + .SH ASSEMBLE MODE .HP 12 @@ -423,6 +451,14 @@ devices and assembly is attempted. In the third (where no devices are listed) all md devices that are listed in the configuration file are assembled. +If precisely one device is listed, but +.B --scan +is not given, that +.I mdadm +acts as though +.B --scan +was given and identify information is extracted from the configuration file. + The identity can be given with the .B --uuid option, with the @@ -438,7 +474,7 @@ any array. The config file is only used if explicitly named with .B --config -or requested with +or requested with (a possibly implicit) .B --scan. In the later case, .B /etc/mdadm.conf @@ -507,16 +543,15 @@ the presence of a can override this caution. To create a "degraded" array in which some devices are missing, simply -give the word -.B missing +give the word "\fBmissing\fP" in place of a device name. This will cause .B mdadm to leave the corresponding slot in the array empty. For a RAID4 or RAID5 array at most one slot can be -.BR missing . +"\fBmissing\fP". For a RAID1 array, only one real device needs to be given. All of the others can be -.BR missing . +"\fBmissing\fP". '''If the '''.B --size @@ -851,6 +886,13 @@ and assemble .B /dev/md0 out of all such devices with a RAID superblock with a minor number of 0. +.B " mdadm --monitor --scan --daemonise > /var/run/mdadm" +.br +If config file contains a mail address or alert program, run mdadm in +the background in monitor mode monitoring all md devices. Also write +pid of mdadm daemon to +.BR /var/run/mdadm . + .B " mdadm --create --help" .br Providew help about the Create mode. |