Swap on a 128 GB server
While rebuilding the root filesystem of my NAS I had to decide how much swap to give it. The machine has 128 GB of ECC RAM and runs a ZFS pool, some containers, and a Spark setup that occasionally gets greedy. The old install had a 976 MB swap LV that wasn’t even in fstab. The folk rule says swap should be at least as large as RAM, which would mean carving 128 GB out of a 929 GB mirrored volume group for something I’d hope never to use. That felt obviously wrong, so I went looking for where the rule comes from. ...