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The third mitigating feature the article forgot to mention is that tmpfs can get paged out to the swap partition. If you drop a large file there and forget it, it will all end up in the swap partition if applications are demanding more memory.
Which is a great reason to have a big swap file now.
Using the example from the article, extracting an archive. Surely that use case is entity not possible using in-memory? What happens if you're dealing with a not-unreasonable 100gb archive? Who runs around with 100gb+ of swap?!
Our default server images come with a 4.4GB /tmp partition...
So typically: swap off on servers. Do they have a server story?
Earlier quoted context omitted.
Which is a great reason to have a big swap file now.
Note though that if you don't have swap now, and enable it, you introduce the risk of thrashing [1] If you have swap already it doesn't matter, but I've encountered enough thrashing that I now disable swap on almost all servers I work with. It's rare but when it happens the server usually becomes completely unresponsive, so you have to hard reset it. I'd rather that the application trying to use too much memory is ki…
…though I’m not sure why we have to think about this in 2025 at all.
Earlier quoted context omitted.
Most systems probably aren't having problems with insufficient RAM nowaday though, do they? And this will reduce wear on your SSD. Also, you can easily disable it: https://www.debian.org/releases/trixie/release-notes/issues....
If you're running it in a VM you might not have all that luxurious RAM. When my Linux VM starts swapping I have to either wait an hour or more to regain control, or just hard restart the VM.
Earlier quoted context omitted.
Which is a great reason to have a big swap file now.
Note though that if you don't have swap now, and enable it, you introduce the risk of thrashing [1] If you have swap already it doesn't matter, but I've encountered enough thrashing that I now disable swap on almost all servers I work with. It's rare but when it happens the server usually becomes completely unresponsive, so you have to hard reset it. I'd rather that the application trying to use too much memory is ki…
The swap story needs a serious upgrade. I think /tmp in memory is a great idea, but I also think that particular /tmp needs a swap support (ideally with compression, ZSWAP), but not the main system.
Swap on servers somewhat defeats the purpose of ECC memory: your program state is now subject to complex IO path that is not end-to-end checksum protected. Also you get unpredictable performance. So typically: swap off on servers. Do they have a server story?
Edit: I think that the use of ZFS for your /tmp would solve this. You get Error Corrected memory writing to an check-summed file system.
Earlier quoted context omitted.
Note though that if you don't have swap now, and enable it, you introduce the risk of thrashing [1] If you have swap already it doesn't matter, but I've encountered enough thrashing that I now disable swap on almost all servers I work with. It's rare but when it happens the server usually becomes completely unresponsive, so you have to hard reset it. I'd rather that the application trying to use too much memory is ki…
Disabling swap on servers is de-facto standard for serious deployments. The swap story needs a serious upgrade. I think /tmp in memory is a great idea, but I also think that particular /tmp needs a swap support (ideally with compression, ZSWAP), but not the main system.
Earlier quoted context omitted.
Most systems probably aren't having problems with insufficient RAM nowaday though, do they? And this will reduce wear on your SSD. Also, you can easily disable it: https://www.debian.org/releases/trixie/release-notes/issues....
If you're running it in a VM you might not have all that luxurious RAM. When my Linux VM starts swapping I have to either wait an hour or more to regain control, or just hard restart the VM.
At least now when I run out of memory it kills processes that consume the most memory. A few years back it used to kill my desktop session instead!
The third mitigating feature the article forgot to mention is that tmpfs can get paged out to the swap partition. If you drop a large file there and forget it, it will all end up in the swap partition if applications are demanding more memory.
I meant this sort of jokingly. I think have a few linux systems that were never configured with swap partitions or swapfiles.