What is Virtualization?
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"Xen (not XenServer) is a third variety in the Linux distributions.
XenServer (not Xen) is its own type of hypervisor, typically supported within its own circles at XenServer.org, but not typically in the main Linux distribution circles. Citrix at one time had took advantage of XenServer as a marketing exploit and sold annual licenses on a per soc"
Xen isn't tied to Linux. Xen is its own hypervisor. XenServer is a distribution of Xen. XenServer is built on Xen + Linux. But Xen itself can be used with any UNIX system. It's been known to be used on Solarid and NetBSD.
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"Linux’s QEMU/KVM is totally free but requires familiarity with a Linux server distribution of choice (Fedora, Red Hat, Debian, Ubuntu, etc"
Not really true, at least on Fedora you can do everything through a web GUI. Don't need to know any more than you need to know of the system underneath ESXi.
The only hypervisor that requires you to really "know anything" is Hyper-V. All the others come optionally with full OS abstraction interfaces. Hyper-V is unique in requiring you to know something of the OS.
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There is no "vSphere free offering", ESXi standalone is what you can run for free, with limitations.
Also, QEMU/KVM is not necessarily QEMU/KVM, KVM can be used separately, and so can QEMU.
And one last thing - in any article involving virtualization, it is important to explain the difference between a hypervisor and a full virtualization management product, as well as the many layers in between. vmkernel is not ESXi and is not vSphere, but people lump everything under VMWare and then do silly comparisons. A pure hypervisor is nothing more than a driver for the AMD-V/Intel VT-D CPU extensions, and nothing else. To turn that into a usable VM you need an emulator for the other hardware a VM has (which is where stuff like QEMU come in) with various levels of optimized hardware emulation and physical hardware access (paravirtualized hardware). These are already two layers of software just to be able to run a VM. And we left out the fact nothing can REALLY run on baremetal, metal needs drivers, so the "pure" hypervisor is really one of the drivers that exist in a set of drivers, schedulers and supporting software, aka the kernel. Xen is one such kernel with the hypervisor included. Linux with KVM makes another such kernel. On top of that you have the base management layer, so that you don't need to type in a 15-line-long command just to get a VM going, this is where you have stuff like libvirt, ESXi and so on. And the you get the datacenter level management layer (vSphere, oVirt) or the IaaS management layer (Openstack Nova, EC2 etc)
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@dyasny said in What is Virtualization?:
vmkernel is not ESXi and is not vSphere, but people lump everything under VMWare and then do silly comparisons.
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
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@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
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@dyasny said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
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@Dashrender said in What is Virtualization?:
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
I totally understand that, been an MCSE before I got into Linux after all. This is a double edged sword - with things like AD, you get a very good integration of the entire stack, true. But the downside is that the entire stack belongs to MS, no parts are interchangeable and you are a hostage in a vendor lock. If MS decide not to develop a feature or not to move in a certain direction, you have to adjust. With the OSS unixway kind of software, you always have options of various degrees of integration quality.
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@dyasny said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
I totally understand that, been an MCSE before I got into Linux after all. This is a double edged sword - with things like AD, you get a very good integration of the entire stack, true. But the downside is that the entire stack belongs to MS, no parts are interchangeable and you are a hostage in a vendor lock. If MS decide not to develop a feature or not to move in a certain direction, you have to adjust. With the OSS unixway kind of software, you always have options of various degrees of integration quality.
Sure you do - along with the complexities that come with managing and maintaining your solution. But yep, you get to mix and match.
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@Dashrender said in What is Virtualization?:
Sure you do - along with the complexities that come with managing and maintaining your solution. But yep, you get to mix and match.
There's always a trade-off
But practice shows the OSS way is more effective in the long run - even MS are moving towards that model, and so do all the tech giants who aren't there yet. -
@Dashrender said in What is Virtualization?:
@dyasny said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
that's completely different. Windows has the "separate" pieces just like Linux. You are seeing the confusion and misunderstanding of typical Windows users lumping all things that they don't understand together. That's very different from a single product actually lumping functionality together.
ZFS is actually three different things rolled into one product. In the Windows world, that would be Windows RAID, NTFS, and WIndows Disk Manager all as one product.
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@dyasny said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
I totally understand that, been an MCSE before I got into Linux after all. This is a double edged sword - with things like AD, you get a very good integration of the entire stack, true. But the downside is that the entire stack belongs to MS, no parts are interchangeable and you are a hostage in a vendor lock. If MS decide not to develop a feature or not to move in a certain direction, you have to adjust. With the OSS unixway kind of software, you always have options of various degrees of integration quality.
With AD it is "tight integration", not bundling, though.
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@scottalanmiller said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
@dyasny said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
that's completely different. Windows has the "separate" pieces just like Linux. You are seeing the confusion and misunderstanding of typical Windows users lumping all things that they don't understand together. That's very different from a single product actually lumping functionality together.
ZFS is actually three different things rolled into one product. In the Windows world, that would be Windows RAID, NTFS, and WIndows Disk Manager all as one product.
Well - then that makes matters just that much worse then!
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@Dashrender said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
@dyasny said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
that's completely different. Windows has the "separate" pieces just like Linux. You are seeing the confusion and misunderstanding of typical Windows users lumping all things that they don't understand together. That's very different from a single product actually lumping functionality together.
ZFS is actually three different things rolled into one product. In the Windows world, that would be Windows RAID, NTFS, and WIndows Disk Manager all as one product.
Well - then that makes matters just that much worse then!
It's not so much that it is worse, it is just different. But people compare it in unreasonable ways.
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Example....
Scientist: I've invented a new hand that can do things better than your old hand.
Person: But can it dance?
Scientist: Um... that's your feet, not your hand.
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@scottalanmiller said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
@dyasny said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
that's completely different. Windows has the "separate" pieces just like Linux. You are seeing the confusion and misunderstanding of typical Windows users lumping all things that they don't understand together. That's very different from a single product actually lumping functionality together.
ZFS is actually three different things rolled into one product. In the Windows world, that would be Windows RAID, NTFS, and WIndows Disk Manager all as one product.
Well - then that makes matters just that much worse then!
It's not so much that it is worse, it is just different. But people compare it in unreasonable ways.
It's worse because as you just pointed out - it's one name to combine three techs... and again as you showed in Windows - each component is named separately, yet tightly integrated and more often than not talked about in a group via one of the key elements, i.e. AD to mean all of the other features that come alone with AD, but aren't AD itself. Now you're saying this is a single name to mean all these things f(ilesystem, logical volume manager, RAID lumped into one). Granted it's because the person isn't educated that ZFS is all these things and not just a Filesystem, but it's reality no matter if you like it or not.
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@Dashrender said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
@Dashrender said in What is Virtualization?:
@dyasny said in What is Virtualization?:
@scottalanmiller said in What is Virtualization?:
This is a really big deal. To make a comparison, it is like how people would compare ZFS (filesystem, logical volume manager, RAID lumped into one) to XFS (just a filesystem.) Then say "can XFS do.... x, y, or z feature that isn't part of the ZFS filesystem" and it made ZFS look good simply because "XFS can't do that." But the XFS ecosystem did it very well, it just wasn't XFS itself doing whatever feature they were asking.
The unix way is to have one product doing one function and doing it well. This is a good and a bad thing really, but it definitely allows for faster development
People coming from Windows (definitely talking about myself here) aren't used to this type of separation in general. They/We are more accustomed to the packages style. When we talk about AD, we don't simply talk about the authentication part, we mean all of it - authentication/Group Polices, etc. So breaking these things down - explaining, over and over and over again that ZFS is a package, and XFS is a single item is critical to get those people on the same page.
Thanks @dyasny for that post - it was very helpful.
that's completely different. Windows has the "separate" pieces just like Linux. You are seeing the confusion and misunderstanding of typical Windows users lumping all things that they don't understand together. That's very different from a single product actually lumping functionality together.
ZFS is actually three different things rolled into one product. In the Windows world, that would be Windows RAID, NTFS, and WIndows Disk Manager all as one product.
Well - then that makes matters just that much worse then!
It's not so much that it is worse, it is just different. But people compare it in unreasonable ways.
It's worse because as you just pointed out - it's one name to combine three techs... and again as you showed in Windows - each component is named separately, yet tightly integrated and more often than not talked about in a group via one of the key elements, i.e. AD to mean all of the other features that come alone with AD, but aren't AD itself. Now you're saying this is a single name to mean all these things f(ilesystem, logical volume manager, RAID lumped into one). Granted it's because the person isn't educated that ZFS is all these things and not just a Filesystem, but it's reality no matter if you like it or not.
The Windows example is worse because that is based on incompetence. The ZFS situation is just an option. Nothing particularly wrong with bundling or with not bundling, just two reasonable approaches. Your entire point of the Windows situation is "used by people who don't understand it." That's the real issue. Not whether they are separate or not.
