I'm experimenting with ways of recording changes to the udev database so you can look back at the history of the storage stack on a particular machine. This is still a work-in-progress, but it's reached a point where I'd like more people to try it out. I've written a shell script that records data related to storage uevents in the system journal and a perl script that helps you to interrogate this data later to create a representation of the storage components. If you're interested, please try this out and let me know if you think pursing this approach further would lead to something that you would use and distributions should ship. Source code: https://github.com/lvmteam/storage-logger Fedora builds: https://copr.fedorainfracloud.org/coprs/agk/storage-logger/build/1320735/ Presentation: https://fosdem.org/2020/schedule/event/storage_logger/ Storage-logger ============== The storage-logger project maintains a record of the storage configuration of a linux system as it changes over time. The idea is to provide a quick way to check the state of a system at times in the past. Logging ======= The initial logging implementation is triggered by storage uevents and consists of two components: 1. A new udev rule file, 99-zzz-storage-logger.rules, which runs after all the other rules have run and invokes: 2. A script, udev_storage_logger.sh, that captures relevant information about devices that changed and stores it in the system journal. The effect is to log relevant uevents plus some supplementary information. It does not yet handle filesystem-related events. Reporting ========= Two methods to query the data are offered: 1. journalctl Reports the raw data using simple filtering. Data is tagged with the identifier UDEVLOG and retrievable as key-value pairs. All the captured data: journalctl -t UDEVLOG --output verbose or as JSON: journalctl -t UDEVLOG --output json Between a time range: --since 'YYYY-MM-DD HH:MM:SS' --until 'YYYY-MM-DD HH:MM:SS' Other filtering features are described in the man page. 2. lsblkj This wrapper creates a dummy system environment that "looks like" the system did at a specified earlier time and then runs lsblk against it. It accepts --since and --until arguments to pass to journalctl to select the desired data, and passes other arguments controlling the output format to the real lsblk. Use --verbose to watch it setting up the temporary environment . Use --dry-run to see what it would do without actually doing it. Use --git to create a git repository recording the changes over time. Alasdair -- agk@xxxxxxxxxx -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
