Figuring out linux’s device mapper
Device mapper does a great job at translating devices to somewhat human readable format. Yet, that layer breaks down in the logging. Let’s take the situation where you have an error in the filesystem that is getting reported in dmesg or syslog: [1297912.800024] EXT4-fs (dm-1): error count: 1 [1297912.800030] EXT4-fs (dm-1): initial error at 1322435090: