cache_writeback(8)

✨ NAME ✨

okay so this is cache_writeback(8) 💖 and it's basically the tool that writes - dirty blocks - back to the origin device 🧚

🎀 SYNOPSIS 🎀

cache_writeback [options] --metadata-device {device|file} --origin-device {device|file} --fast-device {device|file}

🌸 DESCRIPTION 🌸

bestie, cache_writeback is an offline tool 🙈 it writes back dirty data to the data device (origin). it's meant for recovery scenarios where the SSD is throwing IO errors 😭 so like, when your fast device is being dramatic, this is your rescue squad 🫶

⚠️ this tool cannot be run on a live cache. do NOT try it on a cache that's still active 💀

💅 OPTIONS 💅

• -h, --help — print help and exit 🌈
• -V, --version — print version information and exit ✨
• --metadata-device {device|file} — where the cache metadata lives 🧠
• --origin-device {device|file} — the slow device being cached 🐢
• --fast-device {device|file} — the fast device holding the data that needs to be written back ⚡ this is the one with the stuff that needs rescuing 🦋
• --no-metadata-update — don't update the metadata to clear the dirty flags 🙅‍♀️
  • ngl you might want this one if you're decommissioning the cache 🫶
• --buffer-size-meg {size} — sets the size of the data cache, in megabytes 🍓
  • it defaults to 64 MiB, but a bigger size may improve performance 🚀
• --list-failed-blocks — lists any blocks that failed the writeback process 👀

🦋 SEE ALSO 🦋

cache_dump(8), cache_check(8), cache_repair(8), cache_restore(8) 💜

👑 AUTHOR 👑

Joe Thornber <ejt@redhat.com> 🌟

and that's the whole tea, bestie 🫶 this page came from cache_writeback(8), the Device Mapper Tools System Manager's Manual page 💖 periodt ✨