4 ms·
TRIM/UNMAP. A common problem with SSDs is that a host file system could erase free data but didn't have a way of telling the storage device it no longer needed
by Luyt 14y ago
TRIM/UNMAP. A common problem with SSDs is that a host file system could erase free data but didn't have a way of telling the storage device it no longer needed that data. The TRIM/UNMAP interface lets the SSD clear the LBA (logical block addressing) entries in the FTL, giving it more free space to use in garbage collection and reducing write amplification. OS/X, Microsoft Windows, and Linux have implemented TRIM.
FreeBSD has TRIM support, too.
- deleted 14y ago[deleted]
- jethroalias97 14y agoI feel like what they are describing is more defragmentation than garbage collection. The article uses garbage collection to mean taking sparsely filled blocks and consolidating them into a single block to free the sparsely filled ones. Garbage collection in the OO context is where you free memory the program can no longer interact with. Perhaps it means different things in different contexts?
- wmf 14y agoA sparsely-filled block contains some valid data and some old invalid data, i.e. garbage.