For those dealing with SquashFS compressed, read-only file-systems, a new version of the user-space tools were released this week.
SquashFS remains a popular choice for embedded systems for read-only file-system needs as well as the likes of Linux live images. The new 4.7.3 release while a point release does bring a few notable changes.
SquashFS 4.7.3 optimized the reading of sparse files. For file-systems with SEEK_DATA lseek operation to skip holes when reading sparse files, this update can produce a “240 times speed improvement”.
There is an additional speed-up for holes which are multiple SquashFS data blocks in size can now be handled as large multi-block sparse regions to further enhance the read speeds. This gain is said to be a 6x improvement, or in “total 1500 times between these improvements compared to prior releases.
This isn’t the only wild SquashFS performance improvement in recent times as a few months back there was another wild improvement around the file-system driver’s handling also around SEEK_DATA / SEEK_HOLE for sparse files.
SquashFS Tools 4.7.3 also now allows mksquashfs to stream the output file-system to the standard output (STDOUT) if so desired. Plus a new action to align a file to a given value. Plus documentation updates and other changes.
Downloads and more details on the new SquashFS Tools update via GitHub.
