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A deep dive into Debian 13 /tmp: What's new, and what to do if you don't like it

(lowendbox.com)
150 points shaunpud | 1 comments | 29 Aug 25 02:39 UTC | HN request time: 0.212s | source
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fh973 ◴[29 Aug 25 05:37 UTC] No.45060597[source]▶
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?

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abrookewood ◴[29 Aug 25 05:50 UTC] No.45060665[source]▶
That's a really good point that had never occurred to me.

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.

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yjftsjthsd-h ◴[29 Aug 25 06:34 UTC] No.45060900[source]▶
ZFS /tmp is probably fine, but swapping to ZFS on Linux is dicey AIUI; there's an unfortunate possibility of deadlock https://github.com/openzfs/zfs/issues/7734
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cromka ◴[29 Aug 25 08:46 UTC] No.45061712[source]▶
So maybe another filesystem with heavy checksums could be used? Btrfs or dm-crypt with integrity over ext4?
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1. Vogtinator ◴[29 Aug 25 11:58 UTC] No.45062874[source]▶
swapfile on linux must be directly mapped, bypassing any filesystem level checksums (see https://btrfs.readthedocs.io/en/latest/Swapfile.html)