du: cache directory size
Hi, I noticed that du takes a long time to scan directories and measure disk usage. I was thinking that perhaps caching the size of directories could bu useful. Perhaps, after du computes the size of a directory, it could write its size in its extended attributes (if the filesystem support it). Next time, du would only compare the directory atime (or mtime perhaps) with the time of the scan. That could possibly save some time during the scan. Perhaps this is not something to be included in du itself, but I thought it could be a good idea to give the idea anyway. Thanks for reading. Mildred -- Mildred Ki'lya E-Mail: mildred593(at)online.fr Site: http://mildred632.free.fr/ XMPP: [EMAIL PROTECTED] (GoogleTalk, Jabber) GPG:197C A7E6 645B 4299 6D37 684B 6F9D A8D6 [9A7D 2E2B] ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: du: cache directory size
Mildred [EMAIL PROTECTED] writes: I was thinking that perhaps caching the size of directories could bu useful. Perhaps, after du computes the size of a directory, it could write its size in its extended attributes (if the filesystem support it). Next time, du would only compare the directory atime (or mtime perhaps) with the time of the scan. That could possibly save some time during the scan. Just because a directory is unchanged does not mean that all files and subdirectories beneath it are unchanged as well. Andreas. -- Andreas Schwab, SuSE Labs, [EMAIL PROTECTED] SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 And now for something completely different. ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: du: cache directory size
On Wed, 2 Jul 2008, Mildred wrote: I was thinking that perhaps caching the size of directories could bu useful. Perhaps, after du computes the size of a directory, it could write its size in its extended attributes (if the filesystem support it). Next time, du would only compare the directory atime (or mtime perhaps) with the time of the scan. Unfortunately neither the atime nor mtime of a directory would necessarily show a change to the disk usage of the enclosed files. Consider a logfile, for example; the filesize grows continuously, but makes no change to the directory. Cheers, Phil ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: du: cache directory size
Mildred wrote: Hi, I noticed that du takes a long time to scan directories and measure disk usage. I was thinking that perhaps caching the size of directories could bu useful. Perhaps, after du computes the size of a directory, it could write its size in its extended attributes (if the filesystem support it). Next time, du would only compare the directory atime (or mtime perhaps) with the time of the scan. That could possibly save some time during the scan. Those values would be invalidated though once a change has been written anywhere in the tree under a directory. Perhaps this is not something to be included in du itself, but I thought it could be a good idea to give the idea anyway. The idea might be appropriate on a per file basis. For example, md5sum which needs to do significant processing on all of a file's data, could cache the computed value in an extended attribute. You would need support in the filesystem though, to invalidate certain extended attributes on write. Pádraig. ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
Re: du: cache directory size
Le Thu 03/07/2008 à 14:29 Philip Rowlands à écrit: Unfortunately neither the atime nor mtime of a directory would necessarily show a change to the disk usage of the enclosed files. Consider a logfile, for example; the filesize grows continuously, but makes no change to the directory. You're probably right. I thought a modification on a file would change directories times but the test I made must have been incorrect. Thanks everyone Mildred -- Mildred Ki'lya E-Mail: mildred593(at)online.fr Site: http://mildred632.free.fr/ XMPP: [EMAIL PROTECTED] (GoogleTalk, Jabber) GPG:197C A7E6 645B 4299 6D37 684B 6F9D A8D6 [9A7D 2E2B] ___ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils
