Ubuntu To Begin Making Use Of Swapfiles In Place Of SWAP Partitions

[starshipeleven]

Here's a quarter, kid. Get an SSD.

Solving software problems with hardware is Microsoft's way.

[starshipeleven]

Are you fully sure of that? I didn't check the kernel source code from one year ago or so, but I think that it crosses all FS logic (vnode, etc.). Probably I can check it with ftrace.

btrfs's faq seem to indicate that kernel does bypass filesystem and work on blocks directly (but btrfs is different and this approach is dangerous on it) https://btrfs.wiki.kernel.org/index...._swap_files.3F

[fabdiznec]

Fantastic idiotic movement from Ubuntu. If for whatever reason I need to page-out because of memory shortage, now I know that it will crawl even more if I use Ubuntu, thanks to having to cross the filesystem layer to reach the storage. They should call the distribution Microsoft-Linux and recommend it only to desktops.

Not sure if trolling or not, but... crossing the filesystem layer is not a big deal. Your disk (hard drive or SSD, doesn't matter) is at least two orders of magnitude slower than your CPU/RAM. The overhead is completely negligible.

Besides, if the speed of swapping is an issue you already have bigger problems to worry about.

[jpp650]

Not sure if trolling or not, but... crossing the filesystem layer is not a big deal. Your disk (hard drive or SSD, doesn't matter) is at least two orders of magnitude slower than your CPU/RAM. The overhead is completely negligible.

Besides, if the speed of swapping is an issue you already have bigger problems to worry about.

My experience is exactly the contrary. Dedicating an entire VG with raw LVs for swapping is a big difference with respect of using swapfiles, usually when a database server has a runaway SQL query. I don´t think that the difference is negligible under heavy load conditions.

[fabdiznec]

My experience is exactly the contrary. Dedicating an entire VG with raw LVs for swapping is a big difference with respect of using swapfiles, usually when a database server has a runaway SQL query. I don´t think that the difference is negligible under heavy load conditions.

The problem here is the runaway SQL query (as I said, "other worries"). Fix that or get more RAM. Swap is never going to be fast enough, regardless what you do.

[Guest]

Window's swap method works a whole lot better if you need the swap. Even before it needs swap it starts writing pages to swap without removing them from RAM, just in case it needs to swap them.

Windows swap method is crap like entire Windows. It starts using a lot swap when there's RAM available.

[VikingGe]

Window's swap method works a whole lot better if you need the swap. Even before it needs swap it starts writing pages to swap without removing them from RAM, just in case it needs to swap them.

What I find annoying about Windows is that it doesn't over-commit. Now one might argue that this might actually be a good thing because of more predictable out-of-memory behaviour, but it requires me to sit there with a 24GB page file on my hard drive to back 8GB of system RAM + 8GB of VRAM + apparently some other mapped memory regions that aren't actually memory + some space for the few occations where a couple of megabytes actually *need* to be swapped.

[pal666]

No there is, because hypernation with full disk encryption is a pain in the ass ATM.

change swap partition to ext2 an make file on it

[pal666]

Meanwhile, a swap file is great because it's generally more user-friendly. You can more easily enable, disable, and resize it whenever you want.

you can easily resize swap partition by adding swap files. doing file at install time is useless

[Hohlraum]

linux supported this before release of nt 4.0. it is not used by default because it is slower and makes no sense
there is exactly one usecase for swap files: when you already have system and discovered that you need more swap and can't make space available as partition

Actually there is no performance benefit to swap partitions vs swap files.