Big RAM VPS - who actually uses them and for what?
There isn't a specific limit on where they start struggling. Assuming you have the whole server to yourself you could allocate a full 32GB of RAM to one server in OpenVZ or KVM and it would run just fine.
wlanboy
Content Contributer
Ok - good to know.
At home I am using LXC without any problems on a 16 GB machine (splitted into 2 vps).
Thank you for sharing the information.
lbft
Active Member
You can't do that on the cheap high-RAM VPSes though, you'll get booted for CPU abuse. That's where the challenge comes in - actually doing something useful with a lot of RAM without a lot of CPU or disk I/O.
Eased
Member
@lbft, yes this is true. This server is not hosted with a budget provider, and its a VMware virtual machine with "dedicated" resources.
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wlanboy
Content Contributer
So no technical limit but I dopt I would be able to use any shared 4 GB plan.
Second that. If you are using more than 2 GB of RAM (rule of thumb) you need dedicated CPU resources.
So a no-go for shared OpenVZ offers.
wlanboy
Content Contributer
I was thinking about the "real limit" too. You are not using the whole RAM because you need some room for apt-get and peaks.
So 1 GB of real RAM usage, 512 MB for cache/database and 512 MB for peaks and room to live.
This may work for 32 GB servers. so 16 OpenVZ instances - that might work.
But I have to admit for real world usage of big boxes running OpenVZ we have to lower the mark to 1 GB of RAM.
This is not clear at all. I've used a lot of 17GB and 34GB (I don't know why they size them like that) EC2 instances and I believe they're actually Xen VPS's running inside very large physical nodes, like 128GB or 256GB. We also had some 256GB, 16 core physical servers that we ran LXC containers in, most pretty small but some of them 10-20GB. We also used a 60.5GB instance (hi1.4xlarge) for some data analysis, but I get the impression that was a single-tenant server.
I see inceptionhosting has Xen VPS up to 16GB* and they seem more serious than the oversold OpenVZ plans that we see around here. However once we're up in that price range I'd probably get a dedicated server unless the VPS had cloud-like hourly billing.
* https://inceptionhosting.com/usa-xen-vps-phoenix-miami/ -- for some reason the Inception VPS at other locations are much more expensive and only go to 4GB.
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Some clients use their Blue4 plans for MySQL stuff. Load up the DB in RAM instead of thrashing disk and it works MUCH faster. Some other people use them for VNC. With 2GB RAM (and 2GB vSwap) you can load up a GUI and a browser like Firefox, but that sometimes pushes the CPU boundary a bit.
Kvm memory usages is much better than it was years ago. You have the kvm balloon feature with allows you to oversubscribe memory. I have seen some clients use 8G 16G and 32G vps systems both windows and linux. Yes dedicated servers are great but when you virtualize a system and allocate all the resources to it you only lose a few % on the resources but gain a few benefits of a vps ie backups, HA, snapshots, console access and management benefits.
wlanboy
Content Contributer
Yup, but LXC is not a full virtualization.
I am using LXC too to separate my big KVM into manageable (and moveable) containers.
Only services running on my KVM: OpenSSH server, fail2ban and iptables.
Everything else is inside of a LXC container.
Second that.
Containers are moveable. I do have some templates for different purposes.
I like the comfort of:
- LXC inside of KVM:
One click creation of a LXC container including lighttpd, Ruby with all gems and dependencies, MongoDB server, etc with all ssh server, users, keys, etc allready configured. Done in 3 minutes. Recreated in 3 minutes.
- Not talking of easy backup/recover or snapshots.
It depends. If no games are allowed, then 1-2 GB are mostly enough for mundane usage, however, throw in a few MC servers in an OVZ box and RAM will be needed.
We have people use all 8 GB RAM in OVerZold and not maxing the CPU. In fact I move them around so the big ram ones will go on the servers with high cpu usage and the cpu intensive on those that are low on RAM.
Rnning a DB in 8 GB ram should be mighty fast without loading the CPU (I am not talking monsters that need 4x 8 real cores and 512 GB RAM, but usual heavy DBs)
The main usage is shared hosting and games though.
We kept having demand for them (heck, people asked for larger than 8 GB iwstack instances and running heavy Windows inside) but OVZ is not doing everything, so we launched XenPower, less ram but more CPU and disk. It's been a massive hit, yet OVerZold usage does not decrease we barely manage to have stock, and there are tens of 8GB instances in the cloud.
There is a demand for high RAM VPSes, people want HA, snapshots, templates, imprating/exporting VMs installing from own ISO, creating complex setups with isolated networks, load balancing, external firewall, IPSec site-to-site and all with hourly billing, so, an 8 GB instance costs pennies a month if only up for a few hours.
Actually, to be honest I think the demand for high RAM VPSes is bigger than the regular LEBs, I mean there is stock for the lower ones (which is is something new those were flying fast before) and people ask for the big ones, Biz Xen was hardly selling one year ago in 1 GB variants, since then had to create 2 GB ones and even have a few people asking for a merger of two to run 4 GB at a very high price. At that price a dedi is much cheaper, but cant beat the power that a much bigger server can offer when almost all resources are available to you almost all the time if needed. Not to mention RAID, much better network, quiet and few neighbours.
I used to reccomend dedis over 8 GB and iwstack had an 8 GB instance just to have there in case someone will ever need one, but the usage was pretty steep from the start. Now we had to create 16 GB ones where people run DC edition Windows Server.
We have people use all 8 GB RAM in OVerZold and not maxing the CPU. In fact I move them around so the big ram ones will go on the servers with high cpu usage and the cpu intensive on those that are low on RAM.
Rnning a DB in 8 GB ram should be mighty fast without loading the CPU (I am not talking monsters that need 4x 8 real cores and 512 GB RAM, but usual heavy DBs)
The main usage is shared hosting and games though.
We kept having demand for them (heck, people asked for larger than 8 GB iwstack instances and running heavy Windows inside) but OVZ is not doing everything, so we launched XenPower, less ram but more CPU and disk. It's been a massive hit, yet OVerZold usage does not decrease we barely manage to have stock, and there are tens of 8GB instances in the cloud.
There is a demand for high RAM VPSes, people want HA, snapshots, templates, imprating/exporting VMs installing from own ISO, creating complex setups with isolated networks, load balancing, external firewall, IPSec site-to-site and all with hourly billing, so, an 8 GB instance costs pennies a month if only up for a few hours.
Actually, to be honest I think the demand for high RAM VPSes is bigger than the regular LEBs, I mean there is stock for the lower ones (which is is something new those were flying fast before) and people ask for the big ones, Biz Xen was hardly selling one year ago in 1 GB variants, since then had to create 2 GB ones and even have a few people asking for a merger of two to run 4 GB at a very high price. At that price a dedi is much cheaper, but cant beat the power that a much bigger server can offer when almost all resources are available to you almost all the time if needed. Not to mention RAID, much better network, quiet and few neighbours.
I used to reccomend dedis over 8 GB and iwstack had an 8 GB instance just to have there in case someone will ever need one, but the usage was pretty steep from the start. Now we had to create 16 GB ones where people run DC edition Windows Server.
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