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[resolved] mdadm create doesn't create an array

neb

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Trying to create an array:
Code:
mdadm --create --verbose /dev/md3 --level=1 --raid-devices=2 --metadata=0.90 /dev/sda /dev/sdb
the command output only:
Code:
mdadm: size set to 2930266496K
cat /proc/mdstat gives no information about md3
Code:
Personalities : [raid1]
md5 : active raid1 sdf[0] sdg[1]
      976762496 blocks [2/2] [UU]
md7 : active raid1 sdc[0] sdh[1]
      976762496 blocks [2/2] [UU]
md1 : active raid1 sde2[1] sdd2[0]
      4193216 blocks [2/2] [UU]
      bitmap: 1/128 pages [4KB], 16KB chunk
md2 : active raid1 sde3[1] sdd3[0]
      147901184 blocks [2/2] [UU]
      bitmap: 0/142 pages [0KB], 512KB chunk
md0 : active raid1 sde1[1] sdd1[0]
      4193216 blocks [2/2] [UU]
      bitmap: 1/128 pages [4KB], 16KB chunk
dmesg - no information available.
Tell me which logs to look at to get information about why the array is not being created?
 


Wildhair

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--level=1 is likely the culprit. There is no level 1 defined.

If you want to setup a mirrored set, use: --level=1

Reference: Linux Raid Wiki
 
OP
neb

neb

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The version-0.90 superblock limits the number of component devices within an array to 28, and limits each component device to a maximum size of 2TB on kernel version <3.1 and 4TB on kernel version> = 3.1.
link

The array was not assembled due to "--metadata = 0.90", old kernel version and 3TB size.
Everything was successfully created with the command:
Code:
mdadm --create --verbose /dev/md3 --level = 1 --raid-devices = 2 /dev/sda /dev/sdb
 
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