How long is long running? You should be getting the warm caches after at most a few hours.
> Secondly, Kernel swaps out unused pages to SWAP, relieving pressure from RAM. So, SWAP is often used even if you fill 1% of your RAM. This allows for more hot data to be cached, allowing better resource utilization and performance in the long run.
Yes, and you can observe that even in your desktop at home (if you are running something like Linux).
> So, eff it, we ball is never a good system administration strategy. Even if everything is ephemeral and can be rebooted in three seconds.
I wouldn't be so quick. Google ran their servers without swap for ages. (I don't know if they still do it.) They decided that taking the slight inefficiency in memory usage, because they have to keep the 'leaked' pages around in actual RAM, is worth it to get predictability in performance.
For what it's worth, I add generous swap to all my personal machines, mostly so that the kernel can offload cold / leaked pages and keep more disk content cached in RAM. (As a secondary reason: I also like to have a generous amount of /tmp space that's backed by swap, if necessary.)
With swap files, instead of swap partitions, it's fairly easy to shrink and grow your swap space, depending on what your needs for free space on your disk are.
> Yes, and you can observe that even in your desktop...
Yup, that part of my comment was culmination of using Linux desktops for the last two decades. :)
> I wouldn't be so quick. Google ran their servers without swap for ages.
If you're designing this from get go and planning accordingly, it doesn't fit into my definition of eff it, we ball, but let's try this and see whether we can make it work.
> With swap files, instead of swap partitions,...
I'm a graybeard. I eyeball a swap partition size while installing the OS, and just let it be. Being mindful and having good amount of RAM means that SWAP acts as a eviction area for OS first, and as an escape ramp second, in very rare cases.
> Secondly, Kernel swaps out unused pages to SWAP, relieving pressure from RAM. So, SWAP is often used even if you fill 1% of your RAM. This allows for more hot data to be cached, allowing better resource utilization and performance in the long run.
Yes, and you can observe that even in your desktop at home (if you are running something like Linux).
> So, eff it, we ball is never a good system administration strategy. Even if everything is ephemeral and can be rebooted in three seconds.
I wouldn't be so quick. Google ran their servers without swap for ages. (I don't know if they still do it.) They decided that taking the slight inefficiency in memory usage, because they have to keep the 'leaked' pages around in actual RAM, is worth it to get predictability in performance.
For what it's worth, I add generous swap to all my personal machines, mostly so that the kernel can offload cold / leaked pages and keep more disk content cached in RAM. (As a secondary reason: I also like to have a generous amount of /tmp space that's backed by swap, if necessary.)
With swap files, instead of swap partitions, it's fairly easy to shrink and grow your swap space, depending on what your needs for free space on your disk are.