RAID setup: Difference between revisions
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(New page: = Concepts = == Types == * A RAID setup can either be hardware (hardware card that includes a RAID controller, in this case no drivers are needed) or software (in this case Linux drivers...) |
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mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 | mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 | ||
* To deactivate a RAID array: | |||
mdadm --stop /dev/md1 | |||
* To deassociate the partitions from a RAID array: | |||
mdadm --zero-superblock /dev/sda1 | |||
mdadm --zero-superblock /dev/sdb1 | |||
* To obtain the status of an array: | |||
mdadm --detail /dev/md1 | |||
= LVM2 = | = LVM2 = | ||
* LVM is a set of userspace tools that allows dynamic resizing of partitions without rebooting and other stuff like that. Untested yet. | * LVM is a set of userspace tools that allows dynamic resizing of partitions without rebooting and other stuff like that. Untested yet. | ||
Revision as of 19:38, 30 September 2009
Concepts
Types
- A RAID setup can either be hardware (hardware card that includes a RAID controller, in this case no drivers are needed) or software (in this case Linux drivers are needed). There is a third type called firmware RAID that is neither software nor hardware. It seems no drivers are needed but there is a burden on the host CPU.
Possible setups
- RAID 0 is stripping: basically two drives combined into one big drive. If one drive breaks, all data is lost so this is risky.
- RAID 1 is mirroring. There is redundancy but at a high cost.
Tools
- mdadm is used to create the RAID arrays:
mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1
- To deactivate a RAID array:
mdadm --stop /dev/md1
- To deassociate the partitions from a RAID array:
mdadm --zero-superblock /dev/sda1 mdadm --zero-superblock /dev/sdb1
- To obtain the status of an array:
mdadm --detail /dev/md1
LVM2
- LVM is a set of userspace tools that allows dynamic resizing of partitions without rebooting and other stuff like that. Untested yet.