All new Registrations are manually reviewed and approved, so a short delay after registration may occur before your account becomes active.
Dedicated Ram/ Guaranteed Ram... an oldie but a goody that deserves being seen again
After reading another thread here and after answering a similar question a few times on IRC I thought I would bring this one back in to the lime light.
http://www.lowendbox.com/blog/how-to-tell-your-openvz-vps-is-swapping/
Think of this as one of those, how many IOPS do you get, dd results type threads:
tl;dr for people who dont want to read all the info in the link
1) go to: http://hostingfu.com/article/vzfree-checking-memory-usage-inside-openvz-ve
2) wget http://hostingfu.com/files/vzfree/vzfree-0.1.tgz
3) install make gcc, e.g. yum install gcc make or apt-get install make gcc
4) make
5) make install
then run vzfree and you get an output like:
racksrv.com 512MB VPS, zero unplanned down time in 2 years.
Racksrv Nodes are enterprise grade and they have never been featured on LEB.
Total Used Free Kernel: 2048.00M 4.49M 2043.51M Allocate: 512.00M 126.91M 385.09M (512M Guaranteed) Commit: 512.00M 96.02M 415.98M (72.1% of Allocated) Swap: 0.00M (0.0% of Committed)
quickweb 512MB VPS, 1 unplanned outage in 18 months due to disk failure whcih is completely acceptable.
Quickweb seems to have left LEB behind quite some time ago.
Total Used Free Kernel: 2048.00M 5.44M 2042.56M Allocate: 768.00M 192.81M 575.19M (512M Guaranteed) Commit: 512.00M 71.65M 440.35M (34.3% of Allocated) Swap: 0.00M (0.0% of Committed)
The other more simple approach is a little script that long time member @rm wrote
#!/bin/bash cat /proc/user_beancounters | grep -E '(uid|physpages|oomguarpages)' PHYS=`cat /proc/user_beancounters | grep " physpages " | awk '{print $2}'` OOMGUAR=`cat /proc/user_beancounters | grep " oomguarpages " | awk '{print $2}'` SWAP=$(($OOMGUAR-$PHYS)) echo echo Swapped out: $SWAP pages, or $(($SWAP*4096/1024)) KiB
Save that as e.g. scamram, chmod +x scamram and ./scamram
and you get an output like:
uid resource held maxheld barrier limit failcnt physpages 16994 29671 0 2147483647 0 oomguarpages 16995 29672 131072 2147483647 0 Swapped out: 0 pages, or 0 KiB
So essentially it is a good little method to see if any of your dedicated or guaranteed memory is being swapped out on the node due to over allocation.
Comments
But for .32 it reports weird numbers right?
Maybe, they are both 2.6.18 boxes
I am sure we can work out what is what on 2.6.32 boxes given some examples.
Only one of my VPS using 2.6.18
Tried on .32 boxes.
If you want @AnthonySmith I could add this to the lowendwiki?
This are kinda outdated. Most hosts use recent, vSwap enabled OpenVZ kernels nowdays. And it has a different memory model, so these methods wont work.
EDIT: For new, vSwap-enabled (.32) kernels you can just check casual 'free -m' and will show you real info, instead of how old kernels handle this. Still a swap for this aren't real swap usage, its just a vSwap but the pages are still in physical memory. There are a lot of detailed info on this matter here.
So how to know swapping in the node in .32? Is it possible?
How to tell if your OpenVZ provider is overselling: They just are :P
Someone can move it to tutorials?
Great Article,Thank you.
Memory get swapped out all the time, it's not necessarily a sign of "over allocation". It could equally be that the processes using the memory are idle. I see this all the time on OpenVZ VMs.... get a new VM, install some (daemon) stuff, then leave it idle. A few days later some memory will be swapped out. Start actually using the daemon processes (put some traffic through) and the "swapped memory" disappears. I think it's just expected behaviour of the Linux kernel.
Memory gets swapped out on dedicated servers too. It's how the operating system works and what swap is for.
My undersold KVM node has around 500mb in swap and hasn't come close to running out of memory.
Linux may swap out memory tied up by idle processes, and use that memory for caching. There are a few parameters, like swappiness, that give you some control over this on a dedicated box -- or xen/kvm.
The point is not if and when Linux Swaps ram. the point is that this shows if the host node has swapped out your active ram that has been dedicated to the container, i.e. the host node has no option but to move 100mb of your 256mb active commit on your 2GB box in to swap on the host node which would be transparent on the container otherwise (apart from performance)
@AnthonySmith We give like 30-40GB on 16GB servers, and it almost never peaks beyond 8GB.
I find the 256MB Plans are the ones who use all their resources.
@Jacob +1 for honesty, interesting numbers too
Although you should really change your website as your not really offering dedicated RAM
@AnthonySmith It's dedicated, but shared. I'm planning to get the 16GB HNs abit more beefier but they're fine for now.
I would say overselling 50-60% of RAM is sensible, as I can imagine others go for the 80% mark.
haha,
But in the case I described, it's not active ram, it's ram consumed by idle processes that gets swapped out over time. Try installing AMP in a OpenVZ VM (with guaranteed/burst) and leave it idle for a few days, then check....
30-40GB from 16GB is ~250% right?
haha again, this guy cracks me up, the count to 3 rule now has a place.
Sorry what did I do?
You have 16GB of RAM. You over allocate to say 40GB. That's 250% more than what you have. That's how I see it. Not I want to allocate 40GB and assume 20GB might get used.
From a risk management perspective it's about how much more you're selling and pushing it over and how risky it is, not what might get used up.
@concerto49
sorry, nothing I was laughing to much to form a good sentence. That was me laughing at Jacob again after you pointed out his obvious contradiction and saying he should count to 3 before posting
@Jacob
Thank your for sharing some real numbers. 30-40GB on 16GB.
I was guessing that 50% mark. And if I look to my vps systems that might be right. I hardly ever use the "burst RAM" because it is not a guaranteed resource.
E.g. for my new buyvm box: I am allowed to use 128 MB of RAM but I am able to use up to 256 MB for a .. short period ... of time.
Or how should "burst memory" be defined?
Use it as long as no one else use it?
For me its fine because I do not have to shut down any service to do an apt-get upgrade. That is my main use for "bust memory". And I think it is the main purpose, or?
@concerto49 There is always one, It was also posted from my phone.
Back ontopic though, I would be interested to hear other providers numbers or is it top secret?
My figures are:
1GB Ram reserved for the host OS per 16GB
On a 32GB Node I sell 30GB of ram.
So that is dedicated 1:1 pre allocated Ram.
OpenVZ, silly...
I think it is yes but some people seem to like it