Supercharge HDD Write Performance with Linux's dm-writecache
2025-02-03
This article delves into Linux's dm-writecache kernel module, which leverages an NVMe SSD as a write-back cache for slower HDDs, dramatically improving random write performance. The author demonstrates a speed increase of tens of times through experiments comparing random write speeds with and without dm-writecache. The article also covers other caching methods and tools like bcache and ReadyBoost, detailing the configuration of dm-writecache using both LVM2 and the dmsetup utility for those without LVM2. Finally, it summarizes the significant performance gains achieved with dm-writecache and suggests using the remaining NVMe space to cache other slower drives.
Development
Caching