Hi, This script creates a 1 TB thin device (device mapper) backed by 1 GB of physical space. The script then writes more than 1 GB via $BLOCK_SIZE files to XFS. I'm testing to see if recovery can be automated. https://paste.fedoraproject.org/paste/ropelNyOQWCjk3hfK0jltA When the $BLOCK_SIZE passed to dd is 4k - dd gets an error on the file write that exceeds the physical capacity that backs the thin device. XFS doesn't indicate any problems. If I set the $BLOCK_SIZE to 32k - I see entries in the system log that indicate XFS loops retrying the writes. Is that expected? Is it just more likely to happen with larger block sizes? I’m looking to understand how to recover when a thin device runs out of space under XFS. Example system log entries: [ +5.048997] XFS (dm-3): metadata I/O error: block 0xf0000 ("xfs_buf_iodone_callback_error") error 28 numblks 32 [ +1.376913] XFS: Failing async write: 1164 callbacks suppressed [ +0.000004] XFS (dm-3): Failing async write on buffer block 0xf0020. Retrying async write. Thanks for any help, Todd
