Re: Question about slow access to file information

[Adam Dinwoodie <adam@dinwoodie.org>]

On Sat, Jan 14, 2023 at 11:42:58AM +1100, Eliot Moss via Cygwin wrote:
> Dear Cygwin'ers -
> 
> I have a separate drive mounted this way:
> 
> d:/ /cygdrive/d ntfs binary,posix=0,user,noacl,auto 0 0
> 
> One thing I use it for is to store backup files.  These tend to be 2 Gb
> chunks, and there can be hundreds of them in the backup directory.  (The drive
> is 5Tb.)  The Windows Disk Management tool describes it as NTFS, Basic Data
> Partition.
> 
> Doing ls (for example) takes a very perceptible numbers of seconds (though
> whatever takes a long time seems to be cached, at least for a while, since a
> second ls soon after is fast).
> 
> Windows Explorer (for example) and CMD do not seem to suffer this delay.
> 
> Any notion as to what is happening and what I might do to ameliorate it?
> 
> If it matters, the drive is removable (an external WD MyPassport hard drive).

I *suspect* this will be an issue with `ls` querying some file
metadata that are relatively slow to get out of an NTFS system, to
provide a similar interface to native *nix systems, where Windows' tools
unsurprisigly care more about the sorts of file properties that Windows
filesystems are better optimised for.

Based on experience, you might find using `ls --color=never` to be
quicker: querying some of the properties that `ls` likes to use for
colouring the output seems to require a bunch of extra queries to the
filesystem.  Failing that, if you have control over the directory
layout, making the structure deeper with fewer objects in each directory
will probably help.