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b12d437b73
Add the ability to parse and use metadata devices to dm-raid. Although not strictly required, without the metadata devices, many features of RAID are unavailable. They are used to store a superblock and bitmap. The role, or position in the array, of each device must be recorded in its superblock. This is to help with fault handling, array reshaping, and sanity checks. RAID 4/5/6 devices must be loaded in a specific order: in this way, the 'array_position' field helps validate the correctness of the mapping when it is loaded. It can be used during reshaping to identify which devices are added/removed. Fault handling is impossible without this field. For example, when a device fails it is recorded in the superblock. If this is a RAID1 device and the offending device is removed from the array, there must be a way during subsequent array assembly to determine that the failed device was the one removed. This is done by correlating the 'array_position' field and the bit-field variable 'failed_devices'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> |
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| .. | ||
| delay.txt | ||
| dm-crypt.txt | ||
| dm-flakey.txt | ||
| dm-io.txt | ||
| dm-log.txt | ||
| dm-queue-length.txt | ||
| dm-raid.txt | ||
| dm-service-time.txt | ||
| dm-uevent.txt | ||
| kcopyd.txt | ||
| linear.txt | ||
| snapshot.txt | ||
| striped.txt | ||
| zero.txt | ||