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804 points jryio | 3 comments | | HN request time: 0s | source
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speedgoose ◴[] No.45661785[source]
Looking at the htop screenshot, I notice the lack of swap. You may want to enable earlyoom, so your whole server doesn't go down when a service goes bananas. The Linux Kernel OOM killer is often a bit too late to trigger.

You can also enable zram to compress ram, so you can over-provision like the pros'. A lot of long-running software leaks memory that compresses pretty well.

Here is how I do it on my Hetzner bare-metal servers using Ansible: https://gist.github.com/fungiboletus/794a265cc186e79cd5eb2fe... It also works on VMs.

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levkk ◴[] No.45662183[source]
Yeah, no way. As soon as you hit swap, _most_ apps are going to have a bad, bad time. This is well known, so much so that all EC2 instances in AWS disable it by default. Sure, they want to sell you more RAM, but it's also just true that swap doesn't work for today's expectations.

Maybe back in the 90s, it was okay to wait 2-3 seconds for a button click, but today we just assume the thing is dead and reboot.

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henryfjordan ◴[] No.45662349[source]
Does HDD vs SSD matter at all these days? I can think of certain caching use-cases where swapping to an SSD might make sense, if the access patterns were "bursty" to certain keys in the cache
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1. winrid ◴[] No.45662393[source]
It's still extremely slow and can cause very unpredictable performance. I have swap setup with swappiness=1 on some boxes, but I wouldn't generally recommend it.
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2. eru ◴[] No.45663399[source]
HDDs are much, much slower than SSD.

If swapping to SSD is 'extremely slow', what's your term for swapping to HDD?

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3. baq ◴[] No.45665041[source]
‘Hard reboot’ (not OP)