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On 07/18/2011 09:26 PM, Jeff Cranmer wrote: |
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> Hi all, |
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> |
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> After cleaning off my Opensuse O.S. and installing Gentoo, I'm having |
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> trouble getting my 3-disk nvidia SATA raid5 array back on line. |
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> |
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> The gentoo OS is on a separate non-raid IDE disk, and I can see the |
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> three individual disks which make up the raid array (/dev/sda, /dev/sdb |
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> and /dev/sdc). Unfortunately, the system does not seem to be able to |
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> detect the raid array, and dmesg shows no md disks detected or mounted. |
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|
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Make sure your kernel supports RAID, and RAID5 (they're separate |
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options). Then emerge mdadm. Once you get it up and running once, you |
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can dump the current config to /etc/mdadm.conf so you don't have to |
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assemble it again. Then add mdadm to the boot runlevel. |
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|
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# mdadm --assemble --help |
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Usage: mdadm --assemble device options... |
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mdadm --assemble --scan options... |
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|
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This usage assembles one or more raid arrays from pre-existing |
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components. For each array, mdadm needs to know the md device, the |
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identity of the array, and a number of sub devices. These can be found |
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in a number of ways. |
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|
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The md device is either given on the command line or is found listed |
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in the config file. The array identity is determined either from the |
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--uuid or --super-minor commandline arguments, from the config file, |
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or from the first component device on the command line. |
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|
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The different combinations of these are as follows: |
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If the --scan option is not given, then only devices and identities |
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listed on the command line are considered. |
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|
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The first device will be the array device, and the remainder will be |
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examined when looking for components. |
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|
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If an explicit identity is given with --uuid or --super-minor, then |
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only devices with a superblock which matches that identity is |
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considered, otherwise every device listed is considered. |
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|
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If the --scan option is given, and no devices are listed, then |
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every array listed in the config file is considered for assembly. |
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The identity of candidate devices are determined from the config file. |
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|
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If the --scan option is given as well as one or more devices, then |
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Those devices are md devices that are to be assembled. Their identity |
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and components are determined from the config file. |
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|
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If mdadm can not find all of the components for an array, it will |
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assemble it but not activate it unless --run or --scan is given. To |
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preserve this behaviour even with --scan, add --no-degraded. Note that |
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"all of the components" means as many as were present the last time the |
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array was running as recorded in the superblock. If the array was |
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already degraded, and the missing device is not a new problem, it will |
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still be assembled. It is only newly missing devices that cause the |
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array not to be started. |
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