Commandset to help users of dm-writeboost to analyze and report bugs. Written in Rust.

Rustup is the best way to install Rust toolset.

https://github.com/rust-lang-nursery/rustup.rs

Then cargo install to install the commands.

https://www.youtube.com/watch?v=QAXbmr2Rf30

Check if the log was written successfully.

• wbcheck /dev/cache 1 checks the segment ID 1. Returns 0 on success.

Create a WB device (wrapping dmsetup create)

• wbcreate wbdev /dev/backing /dev/cache --reformat creates a WB device with reformatting
• wbcreate wbdev /dev/backing /dev/cache --reformat --read_cache_threshold=4 --writeback_threshold=70 creates a WB device with some settings

Dump the data blocks corresponding to the specified metablock ID.

• wbdump /dev/cache 126 dumps the data block of metablock index 126

Look into the metadata in the cache device.

• wbmeta /dev/cache 0 dumps the superblock metadata (ID 0 is special)
• wbmeta /dev/cache 1 dumps the metadata of segment ID 1

Remove a WB device

• wbremove wbdev removes a WB device after flushing data in RAM buffer and then writing back all cache blocks. This is the way Dmirty Smirnov's writeboost script suggests. (Recommended)
• wbremove wbdev --nowriteback remove a WB device without writing back all cache blocks.

Pretty-print the status line.

• dmsetup status wbdev | wbstatus

Akira Hayakawa ([email protected])