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Why copy folder take lesser time than individual images
- Thread starter novetan
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Shh!, don’t say anything or they will “fix it” by making copying a folder just as long. 😉
Is it fewer motions to drag and drop the folder once rather than several time to do the files individually that saves time? Or, are you saying that the actual copying time is longer?
This may answer your question
Why does copying multiple files take longer time than copying a single file of same size?
Answer (1 of 13): A2A. Basically, when you copy a file, this is what happens: 1. Find file on disk 2. Move read/write-heads into position (this may happen multiple times, depending on how fragmented that file is on your HDD) and read a chunk from that file. 3. Write that chunk to the new file an...
I see. TksThis may answer your question
Why does copying multiple files take longer time than copying a single file of same size?
Answer (1 of 13): A2A. Basically, when you copy a file, this is what happens: 1. Find file on disk 2. Move read/write-heads into position (this may happen multiple times, depending on how fragmented that file is on your HDD) and read a chunk from that file. 3. Write that chunk to the new file an...www.quora.com
I believe that copying a folder is faster than copying the files individually because the copy-on-write feature of APFS just needs to handle the one folder instead of doing all the files individually. Are you using APFS? Can somebody confirm that copy-on-write works for directories, too?
Lol. I don't know what is APFS. If I can get to that level of understanding I may not needed to ask such question.
At least now there are confirmations my findings are correct. So nothing wrong with my com
No...
For an APFS file system, copying a file between folders on the same disk does not involve copying any data. Involves creating new file entries (inodes) pointing to the same data. So is fast. Hence file size does not matter.
Any difference in timing would be that it is quicker to duplicate the folder structure compared with duplicating all the file structures.
Both operations seem to be very fast - either copy and paste a folder or copy and paste the files.
Apple File System. How macOS organises files on your disk. These might help:
https://support.apple.com/en-au/guide/disk-utility/dsku19ed921c/mac
https://www.lifewire.com/apple-apfs-file-system-4117093
https://en.wikipedia.org/wiki/Apple_File_System
Or perhaps not help as it is all techno-babble.
A normal hard link creates a new dentry to an existing inode, are you sure that APFS needs a new inode for a copy-on-write file?
Yes. Nothing to do with hard links. With hard links the data is the same for ever - change one hard linked file and the other file is changed. After an APFS copy, the two files have an independent existence - future changes apply to each file separately.
See "clone" files here: https://eclecticlight.co/2020/04/14/copy-move-and-clone-files-in-apfs-a-primer
They could have layered clones on hard links, lazily creating the new inode on first write, but I just tested it and you are right