Hi everybody
trying to explain in English
I decide to move my personnal server on virtualization
after reading litterature i decide the best choice is KVM instead of Xen , may be i am wrong but …
As i saw the vm machine ares stocked in /var/lib/… so it is a part of the file system of the ““root”” machine
If i got a problem with the dom0 machine i will lose all the vm ??!
it look for me i should change the partition and create a /sdx and mount the /var/lib/… vm with the new partition . in this case i will indepedant from dom0
right ?
note : i have RAID5 disk so I dont care about hardware disk problems
Best
I am a little confused as to what you mean by “personal server”. Is this machine being accessed by people other than yourself?
I know “printer server”, “file server”, “http” or “web” server, etc. etc., but what is a “personal” server?
This did’nt answer to my question but i will
I have a web server it is use to test before to install on some web machine ( i help some organization to creat and maintain web server)
i have my personal machine
i have a windows machine, because i help some friends of my who don’t have knowledge in IT ( i am 77 years old and it is easier to help when you have the menu under my eyes) , i did’nt remember all windows 'subtlety" after more than 20 years under Linux ( suse … )
best
An so some time i will give access to my web server to my “”“clients”“”
with VM it will be a more secure solution
So it is just a web server we are talking about. That is clear then.
Hello @Enthalpie ,
So your real question appears to be
I don’t use either Xen or KVM, so I can’t directly answer your question. Based on what I have read, I too would opt for KVM before Xen. Although I do not KNOW, I would be surprised if you can’t put the files for the VM where you want them.
That said, when I have had the need to run a virtual machine, I have opted for the easiest possible options, namely using vmware or virtualbox.
Unless you have performance requirements that can’t be met by the easier solutions, you should consider these.
hello
I all ready use Vmware( visual ) , but it is not a good solution because performance and installed in a linux
AND !! VM are in home directory !! so if you crash , you loose all vm
with kvm i should put vm where i want if my " solution" is agreed
it is why i want a full virtualization solution
best
Hello @Enthalpie ,
I have spent the last few minutes reading instructions about setting up a VM using KVM. This post made me curious. I think I will try it soon. (Actually, I think I have used it before, just not knowing that I was using it.)
Neither virtualbox, nor vmware, REQUIRE you to create/keep a virtual machine image in your home directory. Your home directory is simply the “default” location. You can create and/or move them where you want them.
From what I have read thus far, KVM appears to work the same way. The default behavior is to create an “image” that acts as the “disk” for the virtualized system.
One thing I remember from VMware, it also allows “raw” access to an actual disk or partition, but I think this feature is only available on the licensed (as in you pay) version. I don’t yet know if KVM allows this as well, but I am beginning to hope that it does!
Question:
What has dom(0) to do with KVM?
I use an extra Partitition on another drive for my images in Qemu/KVM:
ls -al /var/lib/libvirt/images
lrwxrwxrwx 1 root root 23 27. Jun 10:14 /var/lib/libvirt/images -> /mnt/2TB/Container/Qemu
But you can store and loose them on every Partitition…
Backup is your friend.
This doesn’t make sense to me.
VMware Workstation (which I have used for years - since the 1990s) is a full virtualization solution, and it performs just fine, especially for something like you describe, which doesn’t really have any high performance issues.
The biggest issue that can impact performance is if you don’t have enough memory, but that will affect any virtualization solution - you can’t try to do “too much” with a virtualized solution with constrained memory and expect good performance.
VMware also lets you put your VM’s files anywhere. But regardless of where you put them, if the system crashes, depending on what crashed, you can lose data. Whether you use VMware, KVM, Xen, VirtualBox, or QEMU, you can lose data in a system crash.
You’re looking to set up a test environment for someone you do some work for…You could use Docker for that, even - unless you’re trying to mirror the entire system (which makes sense; I’m an admin here, and I have a VM that I host a test environment for these forums on, largely so I can better understand the infrastructure - that runs in VMware).
a) Yes, it does NOT perform if you have an old computer , with low memory, old type hard drives, and old processor.
A modern computer, with a lot of memory, and SSD drives, will perform fine.
b) It’s not required that a VM be in a user /home subdirectory.
If you are going to provide access to your server(s), to clients … and you are not confident at this time how to do it, you might want to speak with a knowledgeable networking and web server person 
why it is not possible to only get answer to a question ?
don’t matter about my networking knowledge
best
I think we’re trying to understand your question.
But the bottom line is that if the host suffers a catastrophic failure, files in a VM (regardless of the technology) are still stored on the host, so whether or not you lose the files depends on the nature of the failure.
BTW, I’ve run RAID5 setups in the past, and while it can be an effective way of protecting a system, it is by no means foolproof. Controller failure, loss of two drives (I had that happen multiple times), and other things can cause a failure of the storage subsystem.
It really depends on the nature of the failure.
Now, if you’re asking if the files are shared between the host and the guest - that’s not what virtualization does, generally. It’s a full “system” with its own filesystem that is manipulated independently of the host (the ‘dom0’ machine in KVM terms). Updates to the host are not pushed to the guest - the guest has to be updated independently (after all, the guest can be any compatible operating system).
@hendersj
Thanks for your answer. it is a little beat more clear for me
I had a bad experience one year ago. when i want to update my leap the Yast installer did’nt see my partition !! I never understand why , but so i backup all : (Home, srv , var, etc ) and reformat my DD , reinstall the same leap version, restore , and after it will be possible to use normal update procedure
I do believe ( 25 years in IT) RAID5 is very strong
the idea after that experience is to have different “machines” and so if i got a problem, it should affect only one
Best regards
@myswtest
could you give me the next loto ? you have some quality to guess …
I can tell you my first test with KVM on my old PC show a better better performance than with vmware workstation
best
@myswtest
If you have 2500$ to give to me i accept and will buy a brand new PC with latest Intel chipset
30+ years in IT here. RAID5 is good, not the end-all, be-all of protection. I had a server at home decades ago with a hardware RAID controller in it, and had multiple drive failures at the same time multiple times (mostly due to thermal issues with keeping the space cool). It actually recovered a few times from that, though.
But backups do handle that pretty handily (I had a DAT autochanger as well, and while DAT itself was a garbage medium, it was sufficient - usually - for what I was backing up).
Regardless of the VM technology, you’ll always be at the mercy of the host system having a failure - there’s no getting around that. But the machines’ “disks” are isolated from the host filesystem (in that changes to the host filesystem aren’t made in the guest, unless you’re using shared folders to mount the host filesystem in the guest, of course).
But if the files are stored in /var on the host (for example) and the partition holding /var gets completely trashed or fails to mount? Yeah, that’s going to affect the guests that have their disk images stored in /var.
There’s no getting around that.
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I am working with Xen for more then 10 years, and very happy with it.
Xen with virt-manager is flexible.
- You can choose where you want your images to reside.
- you can choose a raw image on a partition, a raw image file or even an entire disk.
- then you can do a backup of the raw image file, or dd a partition or disk to an image.
- I imagine KVM can work the same way.
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Hy Enthalpie,
I currently use QEMU for my working activity, whith several VMs using different versions of Windows to respond to old and new HW requirements.
Said that, I can assure you that you can create virtual machine wherever you want.
In my case I use two separate SSD to host my VMs, so there is no limit or impediment to do that.
To make things easier, I advise you to install or to start, depending on which SUSE version you have, the Virtual Machine Manager, a GUI that is very handful creating and organizing virtual machines.
So first run VMM (Virtual Machine Manager), login using root permission as requested, then create all the virtual machine you need.
In order to use a different “FileSystem Directory” you need to click on Edit >> Connections Details and here the “Storage” tab.
You will probably find just the ‘default’ FileSystem Directory, then all you need is to click the “+” icon (down left) and add another FileSystem Directory wherever you want, inside the system disk or in another disk at all.
Once you did this, go back to the main VMM window and start create VMs in the new FileSystem Directory you created.
Previously I was using VMWare and VirtualBox, but VMWare, in my opinion, sooner or later will start to ask a fee for using it, and Virtual Box is extremely easy to setup a VM but is very slow at network.
So I started to use QEMU/KVM, being that a free open source machine emulator, and my experience is simply great.
For network connection I advise you to configure the network adapter using the VMM while creating the virtual machine and to use the “Macvtap device” connected to your phisical network adapter; this configuration will enable the full functions in network.
In order to make the VM a little bit faster, you could be installing the “Virtio” drivers in the Windows machines; just consider that actual virtio drivers exclude Win7.
Hope this helps you.
Roberto
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