Is there any reason not to use use
--sparse=always with every invocation to
info cp says:
‘--sparse=WHEN’ A “sparse file” contains “holes”—a sequence of zero bytes that does not occupy any physical disk blocks; the ‘read’ system call reads these as zeros. This can both save considerable disk space and increase speed, since many binary files contain lots of consecutive zero bytes. By default, ‘cp’ detects holes in input source files via a crude heuristic and makes the corresponding output file sparse as well. Only regular files may be sparse. The WHEN value can be one of the following:
‘always’ For each sufficiently long sequence of zero bytes in the input file, attempt to create a corresponding hole in the output file, even if the input file does not appear to be sparse. This is useful when the input file resides on a file system that does not support sparse files (for example, ‘efs’ file systems in SGI IRIX 5.3 and earlier), but the output file is on a type of file system that does support them. Holes may be created only in regular files, so if the destination file is of some other type, ‘cp’ does not even try to make it sparse.
It also says:
[...] with the following alias, ‘cp’ will use the minimum amount of space supported by the file system.
alias cp='cp --reflink=auto --sparse=always'
--sparse=always the default?