Quote:
Originally Posted by selfprogrammed
I would not do that because of all the version dependent history and caches kept in hidden directories, so my /home is always with its Linux.
|
Same here. I also agree with most of the rest of what you wrote, but ...
Quote:
4. Of course putting the swap at the farthest partition makes for slowest swap paging, so if there is any heavy swapping it needs to be centered.
|
Heavy swapping is an almost entirely obsolete concept. A swap partition is used as a minor optimization to keep stale anonymous memory from competing with active file mappings, and it is a safety valve for situations with unusually high anonymous memory use. Each of those implies the actual transfers to/from swap are rare. All that matters is that the space exists. Farthest partition is fine.
I use a swap partition instead of a swap file so it can be shared between distributions or across a reinstall. (I don't use the feature of suspend to disk, which would change and complicate the decisions regarding swap space).
Quote:
7. /tmp on a separate drive, when speed is needed. Because /tmp files are not discovered upon reboot, I expect there is little conflict in using the same /tmp for several Linux versions. /tmp on a separate partition when space needs to be conserved (but /tmp access will be slower because of extra head travel).
|
I almost always make /tmp a tmpfs (and allow for that when deciding the swap size).
I haven't run into a situation where the size of /tmp usage is large enough that active data in /tmp goes to/from swap. Stale /tmp data getting written to swap has the same performance characteristics as stale anonymous data written to swap.
File caching works well enough that data frequently read from a file on any partition will stay in ram and not really be read from disk. So a tmpfs is not faster than a normal partition for such things. But for short lived files a tmpfs is much more efficient in creating and destroying the directory info of the file. When a small file is created, written once, read once, and then quickly deleted, the directory operations in a normal file system are a significant fraction of the total work. In a tmpfs, those directory operations are trivial. So a tmpfs has a big advantage if you have such files.
Using ram and a shared swap partition for /tmp has the extra advantage that the space is shared across multiple Linux installs.
When I reinstall Linux, I prefer to shrink (rather than initially destroy) the old one. Then install the new one in its own partition set up to dual boot with the old one. Then I switch back and forth a few times to make sure I understand the changes and didn't forget to restore any settings or customizations I wanted. It is hard to guess what settings need backup before the reinstall. It is easier to copy them from a full shrunken original partition than from a backup.
I keep any very large data files in a data partition. If they ought to appear to be in subdirectories of home, I can soft link them there. That and shared swap etc. (and a large drive) means it is not a tight squeeze to reinstall Linux to a new partition before removing it from the old one.