Steal time is the percentage of time a virtual CPU waits for a real CPU while the hypervisor is servicing another virtual processor.
It’s shown as st in top.
I have one VPS with dedicated CPU usage (BuyVM), and a few others with “fair share” CPU usage.
What I’m noticing is that the BuyVM and one other VPS with fair share CPU (BudgetNode storage KVM) have close to no “stolen” CPU time (less than 1%), whereas two of the others constantly have stolen CPU > 5% (one of them peaks around 20-30%)
My CPU usage is quite low on all of these, so this just seems like noisy neighbors on the same node. In fact the BuyVM sees the highest load from me, and yet also has the best performance out of all of them in terms of both CPU and disk IO.
Understandably, stolen CPU time is expected with a VPS without dedicated CPU time (“fair share”), but how much stolen CPU time is expected? Is 5% normal? What about 20%? The only time I’ve ever submitted a support ticket about this was on BuyVM, and that’s because the CPU is supposed to be dedicated there (so stolen CPU should be ~0%). Turns out that was an issue on the node, and Francisco fixed it
Tbh if you’re seeing any there’s a good chance the provider needs to kick out someone who thinks CPU mining is a good idea. The amount of CPU you have to oversell to see legitimate usage using 50% of it on any regular basis is insane.
Not proud to say @Daniel is talking about one of my nodes. Had a few growing pains, they’re getting resolved but unfortunately a couple of customers have felt it. I’m doubling the node capacity in May and implementing automated CPU throttling for people who use more than their fair share.
I’m doing the best I can to rectify @Daniel’s issue, still waiting on him to confirm but hopefully it’s closed out.
Thanks @Brendan! I was being careful to not name any providers negatively, but I guess you found my post I’m keeping an eye on it and collecting more data (both for CPU and for disk IO), and will report back tomorrow.
I guess it’s worth mentioning that the other VPS with high stolen CPU time (albeit without the large peaks) is with VirMach. However, it’s one of their ridiculously cheap Black Friday sale VPSes (~$39 per year for 8 GB RAM, 60 GB SSD, 10 Gb/s connection), which at their price points I expect to have some amount of oversold CPU.
I got moved to another node yesterday. The stolen CPU time is noticeably lower on the new node. There’s still spikes, but they’re lower than before (although still over 10% at times). Will monitor it for a week to see how often it spikes.
lol, if you think that’s amazing, VirMach had an “8” deal on either Black Friday or Cyber Monday: 8 CPU cores, 8 GB RAM, 80 GB SSD, 8 IPs for $8 per year, with only 8 in stock. I think it was the “@FAT32 special”. I tried to get it but their billing system collapsed and I failed.