I/O error on louvre:/dev/md3

The /dev/md3 RAID volume on louvre failed this morning.

Volume composition [cat /proc/mdstat]:

md3 : active raid10 dm-11[0](F) dm-13[1]
      3750605824 blocks super 1.2 512K chunks 2 far-copies [2/1] [_U]
      bitmap: 22/28 pages [88KB], 65536KB chunk```


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*Migrated from T1518 ([view on Phabricator](https://forge.softwareheritage.org/T1518))*