Wikipedia:Reference desk/Archives/Computing/2017 June 8

= June 8 =

windows 10 and annoying taskbar behaviour
hi all, another win 10 irritation ... on the taskbar, when I have eg. two different instances of firefox running, I can't get two different icons on the taskbar. I have to click the single icon, then it shows me two screens, then I have to click the right one. This irritates the heck out of me. How do I change it? Better, can I get back the whole vista taskbar, which has the title of the open window? Win 10 is mostly an improvement, but I worry that some weirdos have taken over the look and feel (Cortana etc). IBE (talk) 02:17, 8 June 2017 (UTC)


 * See if this helps. Look for Taskbar Buttons options under Taskbar properties (right mouse click on the Taskbar). manya (talk) 06:22, 8 June 2017 (UTC)


 * Excellent, should have done more googling first, sorry there ;(, otoh, I have been consuming so much time with so many related windows 10 things, that I was pretty much going mad. At least that's the excuse I'm using, cheers, IBE (talk) 06:28, 8 June 2017 (UTC)

docker layers - deleted files
I can see how docker can overlay "layers" of files if you add or change a file in a newer layer that one is seen. How does Docker manage if you remove a file in a later layer? -- Q Chris (talk) 09:27, 8 June 2017 (UTC)


 * "Each layer has an archive of the files which have been added, changed, or deleted relative to its parent layer" - so it uses a union mount (or, as there can be many layers, a series of concentric union mounts). -- Finlay McWalter··–·Talk 10:36, 8 June 2017 (UTC)


 * Hmm, on thinking about it, probably not concentric mounts, that's overcomplicating it. -- Finlay McWalter··–·Talk 11:54, 8 June 2017 (UTC)


 * As to the matter of deletion specifically, The Design and Implementation of the 4.4BSD Operating System by McKusick et al. (p236) has a nice explanation "The tricky part ... is handling the removal of files that reside in a lower layer. Since the lower layers cannot be modified, the only way to remove a file is to hide it by creating a whiteout directory entry in the top layer ... If the kernel finds a whiteout entry while searching for a name, the lookup is stopped and the 'no such file' error is returned." I think most subsequent union filesystem implementations work the same as the early BSD one described there. -- Finlay McWalter··–·Talk 10:46, 8 June 2017 (UTC)