diff options
Diffstat (limited to 'mdadm.8.in')
| -rw-r--r-- | mdadm.8.in | 26 |
1 files changed, 17 insertions, 9 deletions
@@ -1018,16 +1018,24 @@ immediately start recovering data on to one of these spares. .TP .BR \-\-re\-add -re-add a device that was recently removed from an array. This is only -needed for arrays that have be built (i.e. with +re\-add a device that was recently removed from an array. This is +normally only needed for arrays that have be built (i.e. with .BR --build ). -For created arrays, devices are always re-added if that is possible. -When re-adding a device, if nothing has changed on the array since the +For created arrays, devices are always re\-added if that is possible, +however using \-\-re\-add will ensure the device isn't made into a +spare if the \-\-re\-add failed. + +When re\-adding a device, if nothing has changed on the array since the device was removed, no recovery is performed. Also, if the array has -a write-intent bitmap, then the recovery performed after a re-add will +a write-intent bitmap, then the recovery performed after a re\-add will be limited to those blocks which, according to the bitmap, might have changed since the device was removed. +If the device name given is +.B missing +then mdadm will try to find any device that looks like it should be +part of the array but isn't and will try to re\-add all such devices. + .TP .BR \-r ", " \-\-remove remove listed devices. They must not be active. i.e. they should @@ -1062,12 +1070,12 @@ same as .TP .BR \-\-write\-mostly -Subsequent devices that are added or re-added will have the 'write-mostly' +Subsequent devices that are added or re\-added will have the 'write-mostly' flag set. This is only valid for RAID1 and means that the 'md' driver will avoid reading from these devices if possible. .TP .BR \-\-readwrite -Subsequent devices that are added or re-added will have the 'write-mostly' +Subsequent devices that are added or re\-added will have the 'write-mostly' flag cleared. .P @@ -1082,7 +1090,7 @@ Each operation applies to all devices listed until the next operation. If an array is using a write-intent bitmap, then devices which have -been removed can be re-added in a way that avoids a full +been removed can be re\-added in a way that avoids a full reconstruction but instead just updates the blocks that have changed since the device was removed. For arrays with persistent metadata (superblocks) this is done automatically. For arrays created with @@ -1691,7 +1699,7 @@ command. When a device is added to an active array, mdadm checks to see if it has metadata on it which suggests that it was recently a member of the -array. If it does, it tried to "re-add" the device. If there have +array. If it does, it tries to "re\-add" the device. If there have been no changes since the device was removed, or if the array has a write-intent bitmap which has recorded whatever changes there were, then the device will immediately become a full member of the array and |