Re: squashfs wo compression = speed up?
mksquashfs has several parameters to compress/not-compress various parts of the filesystem.
-noI do not compress inode table
-noD do not compress data blocks
-noF do not compress fragment blocks
-noX do not compress extended attributes
There are also several compression algorithms to choose from.
There is of course no advantage in using squashfs w/o compression, but yes it works as expected.
Btrfs supports compression too, fyi.
When you compress files, this reduces the amount of block I/O and increases the amount of data that appears in memory buffers, so it can make the disk I/O much less and therefore faster. However the negative side is that you must use CPU resource to uncompress on reads and compress on writes and that takes some time. Whether this is a net plus of minus depends on the application, the disk speed, the CPU performance and such.
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