• Contents
• Purpose
• Resolution summary
• Failing test case
• Overview
• Tested environments
• Rocky
• Ubuntu (old)
• Ubuntu (new)
• Test methodology
• Results
• Typical failure output
• Matrix
• Explanations with kernel code
• How to obtain kernel code
• Rocky
• Ubuntu
• Do fsfreeze and dmsetup suspend call the same code?
• Investigation methodology
• Evidence
• dmsetup suspend
• fsfreeze -f
• Why does ext4 always fail on Rocky (with both dmsetup suspend and fsfreeze) but always succeed on Ubuntu (old)?
• Why does xfs always fail when fsfreeze is used?
• Why does xfs always succeed when dmsetup suspend is used?
• Why do all tests pass for Ubuntu (new)?
• Other investigation questions
• Does dmsetup suspend freeze all file systems on a block device?
• Quick answer
• Test methodology
• Results
• Suspend the overall device
• Suspend a partition of the device
• Can we reduce danger by calling sync before dmsetup suspend or fsfreeze?
• Quick answer
• Results
• How do these methods impact block mode volumes?
• fsfreeze
• Quick answer
• Evidence
• dmsetup suspend
• Quick answer
• Evidence