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Special Forums Hardware Filesystems, Disks and Memory Slow copy (cp) performance when overwriting files Post 302831993 by jim mcnamara on Friday 12th of July 2013 11:09:22 AM
Old 07-12-2013
Also consider that
IF:
directory has large numbers of entries - >40K (varies with filesystem type)

Cure: make a directory tree, with each subdirectory having way smaller numbers of files.

Overly full disks can result in fragmented files which trashes update (cp overlay) performance of larger files.

So: You can experience lots of delay finding and overwriting files.

Another cause is poor inode caching. This is OS specific, I cannot comment specifically. But when you try to find a file in a directory, the kernel checks the inode cache first. If it finds the file in the cache it can open the file right away without having to scan thru a huge directory. inode caching also impacts the efficiency of PATH searching.
 

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GTK-UPDATE-ICON-C(1)						  [FIXME: manual]					      GTK-UPDATE-ICON-C(1)

NAME
gtk-update-icon-cache - Icon theme caching utility SYNOPSIS
gtk-update-icon-cache [--force] [--ignore-theme-index] [--index-only] [--source [name]] [--quiet] [--validate] {iconpath} DESCRIPTION
gtk-update-icon-cache creates mmap()able cache files for icon themes. It expects to be given the path to a icon theme directory containing an index.theme, e.g. /usr/share/icons/hicolor, and writes a icon-theme.cache containing cached information about the icons in the directory tree below the given directory. GTK+ can use the cache files created by gtk-update-icon-cache to avoid a lot of system call and disk seek overhead when the application starts. Since the format of the cache files allows them to be mmap()ed shared between multiple applications, the overall memory consumption is reduced as well. OPTIONS
--force, -f Overwrite an existing cache file even if it appears to be uptodate. --ignore-theme-index, -t Don't check for the existence of 'index.theme' in the icon theme directory. Without this option, gtk-update-icon-cache refuses to create an icon cache in a directory which does not appear to be the toplevel directory of an icon theme. --index-only, -i Don't include image data in the cache. --source, -c Output a C header file declaring a constant name with the contents of the icon cache. --quiet, -q Turn off verbose output. --validate, -v Validate existing icon cache. BUGS
None known yet. [FIXME: source] 05/02/2010 GTK-UPDATE-ICON-C(1)
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