Non-Destructive Linux MD RAID 10 Growth?
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Simple one, conceptually, I have a situation where we want to non-destructively grow a Linux software RAID 10 array. No LVM available (not my choice) so need the RAID operation itself to be able to handle the grow. My guess is that there is no option, but looking into it. Anyone tried this?
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Upgrade one drive to a larger drive, let the rebulid complete... and repeat?
In the end, it may require a reboot so that the raid controller will recognize the larger disks.
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Not sure. I believe the man page says it can only grow RAID 0/1/5/6
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From kernel.org: When new disks are added, existing raid partitions can be grown to use the new disks. After the new disk was partitioned, the RAID level 1/4/5/6 array can be grown for example using this command
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@dafyre said:
Upgrade one drive to a larger drive, let the rebulid complete... and repeat?
In the end, it may require a reboot so that the raid controller will recognize the larger disks.
Cloud, can't switch drives.
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@coliver said:
Not sure. I believe the man page says it can only grow RAID 0/1/5/6
That's always been my understanding. Hoping that there is a way to grow a RAID 0 stripe, but I am pretty sure that there is not.
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In this particular use case, a span would be acceptable rather than a move to grow the RAID 0 stripe. But I don't know of that being an option either, sans LVM.
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This link suggests that it can be done, but not in this scenario...
http://serverfault.com/questions/497661/mdadm-growing-a-raid0-array-weirdness
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Newer man page for MDADM adds RAID 0...
Grow (or shrink) an array, or otherwise reshape it in some way. Currently supported growth options including changing the active size of component devices and changing the number of active devices in Linear and RAID levels 0/1/4/5/6, changing the RAID level between 0, 1, 5, and 6, and between 0 and 10, changing the chunk size and layout for RAID 0,4,5,6, as well as adding or removing a write-intent bitmap.
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If it's a cloud system why are you using RAID 10 with it?
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From http://lwn.net/Articles/565591/
RAID10 arrays can be reshaped to change the number of devices,
change the chunk size, or change the layout between 'near'
and 'offset'.
This will always change data_offset, and will fail if there is no
room for data_offset to be moved. -
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@scottalanmiller said:
@dafyre said:
If it's a cloud system why are you using RAID 10 with it?
I didn't build it.
Sure... Sure... Blame it on the other guys... If you can't fix it the easy way, at least you have a chance to redo it right.
