Some may be bored with the subject - sorry... Still not decided about virtualization platform for my "webhotel v2" (ns, mail, web servers, etc.). KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 will not be out in time for me - I guess KVM would be more mature in CentOS 6. Any experience with the free "VMware vSphere Hypervisor"?. (It was formerly known as "VMware ESXi Single Server" or "free ESXi".) http://www.vmware.com/products/vsphere-hypervisor/overview.html I would need a tutorial about that... For example, does that run without a host OS? Can it be managed only via Win clients? Issues with CentOS 4/5 guests (all my systems are currently CentOS 4/5). - Jussi -- Jussi Hirvi * Green Spot Topeliuksenkatu 15 C * 00250 Helsinki * Finland Tel. +358 9 493 981 * Mobile +358 40 771 2098 (only sms) jussi.hirvi at greenspot.fi * http://www.greenspot.fi
On 03/27/11 11:57, Jussi Hirvi wrote:> Some may be bored with the subject - sorry... > > Still not decided about virtualization platform for my "webhotel v2" > (ns, mail, web servers, etc.). > > KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 > will not be out in time for me - I guess KVM would be more mature in > CentOS 6. > > Any experience with the free "VMware vSphere Hypervisor"?. (It was > formerly known as "VMware ESXi Single Server" or "free ESXi".) > > http://www.vmware.com/products/vsphere-hypervisor/overview.html > > I would need a tutorial about that... For example, does that run without > a host OS? Can it be managed only via Win clients? Issues with CentOS > 4/5 guests (all my systems are currently CentOS 4/5). > > - Jussi >VMware ESXi is definitely a good choice. I use it at work (the free version as well) and haven't regretted it. No tutorials needed, everything's pretty straightforward. Yes, it can only be graphically managed from Windows clients (vsphere client), however the command line tools are available for Linux as well. Tried running the vsphere client using wine but that didn't work. No issues with CentOS 5 guests here. Glenn
On 03/27/2011 02:57 AM, Jussi Hirvi wrote:> Some may be bored with the subject - sorry... > > Still not decided about virtualization platform for my "webhotel v2" > (ns, mail, web servers, etc.). > > KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 > will not be out in time for me - I guess KVM would be more mature in > CentOS 6. > > Any experience with the free "VMware vSphere Hypervisor"?. (It was > formerly known as "VMware ESXi Single Server" or "free ESXi".) > > http://www.vmware.com/products/vsphere-hypervisor/overview.html > > I would need a tutorial about that... For example, does that run without > a host OS? Can it be managed only via Win clients? Issues with CentOS > 4/5 guests (all my systems are currently CentOS 4/5).I'm currently using Ubuntu Server 10.04-LTS as a host for KVM running CentOS5.5 guests I migrated from VMware Server 2. Works fine. A nice feature of current generation KVM is that you are supposed to be able to do live migration even without shared storage (although I haven't tested that yet). I wrote some custom scripts to allow me to take LVM snapshots for whole-image backups and I'm pretty happy with the who setup. The only corners I encountered were 1) A lack of documentation on how to configure bridging over bonded interfaces for the host server. It turned out to be fairly easy - just not clearly documented anyplace I could find. 2) The default configuration for rebooting/shutting dow the host server just 'shoots the guests in the head' rather than having them shutdown cleanly. :( You will want to write something to make sure they get shutdown properly instead. -- Benjamin Franz
> Any experience with the free "VMware vSphere Hypervisor"?. (It was > formerly known as "VMware ESXi Single Server" or "free ESXi".) > > http://www.vmware.com/products/vsphere-hypervisor/overview.html > > I would need a tutorial about that... For example, does that run without > a host OS? Can it be managed only via Win clients? Issues with CentOS > 4/5 guests (all my systems are currently CentOS 4/5).vSphere ESX(i) is good product. It runs on bare metal so there is no OS underneath it. ESX has a linux based environment that sort of runs at the hypervisor level that people use for basic admin but VMware is trying to phase that out as most everything you can do with ESX's "console" can be done through ESXi's API's and the remote CLI. Only downside to the free version is certain API's are unavailable and if you need those features you may have to go to a paid version. -- Drew "Nothing in life is to be feared. It is only to be understood." --Marie Curie
On Sun, 27 Mar 2011, Jussi Hirvi wrote:> KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 > will not be out in time for me - I guess KVM would be more mature in > CentOS 6.I have been using Xen with much success for several years, now with two CentOS 5.5 x86_64 Dom0's, hosting 29 (mixed Linux and Windows) and 30 (all Windows) guests respectively, using only packages from the distro along with the GPLPV drivers on the Windows guests (so it's Xen 3.1, not the latest). A couple of weeks ago I decided (on the first of these hosts) to give KVM a look, since I was able to take the machine down for a while. All guests use LVM volumes, and were unchanged between Xen and KVM (modulo pv drivers). The host is a Dell PE2900 with 24 GB memory and E5345 processors (8 cores). Bridged mode networking. What follows is obviously specific to my environment, so YMMV. The short story is that I plan to keep using KVM. It has been absolutely solid and without any issues whatsoever, and performance is significantly better than Xen in all areas that I have measured (and also in the "feels good" benchmark). Migration from Xen to KVM was almost trivially simple. The slightly longer story... First. With Xen I was never able to start more than 30 guests at one time with any success; the 31st guest always failed to boot or crashed during booting, no matter which guest I chose as the 31st. With KVM I chose to add more guests to see if it could be done, with the result that I now have 36 guests running simultaneously. Second. I was never able to keep a Windows 7 guest running under Xen for more than a few days at a time without a BSOD. I haven't seen a single crash under KVM. Third. I was never able to successfully complete a PXE-based installation under Xen. No problems with KVM. Fourth. My main work load consists of a series of builds of a package of about 1100 source files and about 500 KLOC's; all C and C++. Here are the elapsed times (min:sec) to build the package on a CentOS 5 guest (1 vcpu), each time with the guest being the only active guest (although the others were running). Sources come from NFS, and targets are written to NFS, with the host being the NFS server. * Xen HVM guest (no pv drivers): 29:30 * KVM guest, no virtio drivers: 23:52 * KVM guest, with virtio: 14:38 Fifth: I love being able to run top/iostat/etc on the host and see just what the hardware is really up to, and to be able to overcommit memory. Steve
On 3/27/11 4:57 AM, Jussi Hirvi wrote:> Some may be bored with the subject - sorry... > > Still not decided about virtualization platform for my "webhotel v2" > (ns, mail, web servers, etc.). > > KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 > will not be out in time for me - I guess KVM would be more mature in > CentOS 6. > > Any experience with the free "VMware vSphere Hypervisor"?. (It was > formerly known as "VMware ESXi Single Server" or "free ESXi".) > > http://www.vmware.com/products/vsphere-hypervisor/overview.html > > I would need a tutorial about that... For example, does that run without > a host OS? Can it be managed only via Win clients? Issues with CentOS > 4/5 guests (all my systems are currently CentOS 4/5).The free ESXi version is very good. While it doesn't support all the bells and whistles of the paid version, there are hardly any disadvantages compared to running the VMs on physical machines. You do have to use a windows box to manage it (with the advantage of being able to use the media on the client for the install source), but once the guest networking is up you can use whatever you would use for remote access to a physical box (vnc, ssh, X, freenx, etc.) directly to the guest - so the windows box doesn't have to be server-quality or available all the time. You might even be able to use the converter tool to migrate your running systems there - I've usually been able to do that with windows systems but couldn't get it to recognize my linux boxes with software raid (and didn't try any others since they aren't that hard to re-create). By the way, the current version of ESXi permits ssh without the 'unsupported' hack so you can copy images over scp or to/from an nfs mount, but it's not all that much faster than running the converter tool on another machine anyway. -- Les Mikesell lesmikesell at gmail.com
On 03/27/11 2:57 AM, Jussi Hirvi wrote:> Any experience with the free "VMware vSphere Hypervisor"?. (It was > formerly known as "VMware ESXi Single Server" or "free ESXi".)one downside to ESXi, it does not support any sort of software raid. Normally ESX is used with a SAN, which provides all RAID functionality, or with NFS based storage (again, the NFS server providing the raid), but if you use it with direct attached storage, you had better have a supported hardware raid controller. Most server kit from the big vendors is fully supported (HP,Dell,IBM). You can boot ESXi from a small CF card, as once its booted, it doesn't touch the boot device at all.
On 03/27/2011 09:00 AM, Jerry Franz wrote:> > On 03/27/2011 02:57 AM, Jussi Hirvi wrote: >> > Some may be bored with the subject - sorry... >> > >> > Still not decided about virtualization platform for my "webhotel v2" >> > (ns, mail, web servers, etc.). >> > >> > KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 >> > will not be out in time for me - I guess KVM would be more mature in >> > CentOS 6. >> > >> > Any experience with the free "VMware vSphere Hypervisor"?. (It was >> > formerly known as "VMware ESXi Single Server" or "free ESXi".) >> > >> > http://www.vmware.com/products/vsphere-hypervisor/overview.html >> > >> > I would need a tutorial about that... For example, does that run without >> > a host OS? Can it be managed only via Win clients? Issues with CentOS >> > 4/5 guests (all my systems are currently CentOS 4/5). > I'm currently using Ubuntu Server 10.04-LTS as a host for KVM running > CentOS5.5 guests I migrated from VMware Server 2. Works fine. A nice > feature of current generation KVM is that you are supposed to be able to > do live migration even without shared storage (although I haven't tested > that yet). I wrote some custom scripts to allow me to take LVM snapshots > for whole-image backups and I'm pretty happy with the who setup. > > The only corners I encountered were > > 1) A lack of documentation on how to configure bridging over bonded > interfaces for the host server. It turned out to be fairly easy - just > not clearly documented anyplace I could find. > > 2) The default configuration for rebooting/shutting dow the host server > just 'shoots the guests in the head' rather than having them shutdown > cleanly.:( You will want to write something to make sure they get > shutdown properly instead. >Once in a while I find it's useful to compromise just a little, so I use Scientific Linux 6 as the Host OS, and run a bunch of CentOS-5.5 Guest VMs. It all simply works. KVM has improved quite a bit, and the management tools work well. One thing that requires a bit of skill is getting bridging configured (which I simply did by hand from the RHEL-6 documentation). I'm happy with the result, and see no reason to replace the underlying SL-6 Host distro. SL-6 as the Host is rather slow to shut down gracefully and reboot, because it hibernates the Guest OSs, one at a time, rather than just killing them. Hibernation takes a while to write out to disk if you've assigned a lot of RAM to the Guests. Bootup has to restore the saved state, so that's a bit slow too. But it works very well. I use partitionable RAID arrays for the Guests, and assign a "raw" md device to each one rather than using the 'filesystem-in-a-file' method. It seems to be a bit faster, but there's a learning curve to understanding how it works. One thing I found a bit annoying is the very long time it takes for a Guest to format its filesystems on the RAID-6 md device assigned to it. That's mostly due to array checksum overhead. RAID-10 would be a *lot* faster but somewhat less robust ... you pick what's best for your own situation. Chuck
Please also consider OpenNode - http://opennode.activesys.org - a CentOS based KVM full virtualization + OpenVZ linux containers solution. Supports VM templating and live migration, etc - with easy bare metal setup. Cheers, -- ---------------------------------------------- Andres Toomsalu, andres at active.ee On 27.03.2011, at 12:57, Jussi Hirvi wrote:> Some may be bored with the subject - sorry... > > Still not decided about virtualization platform for my "webhotel v2" > (ns, mail, web servers, etc.). > > KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 > will not be out in time for me - I guess KVM would be more mature in > CentOS 6. > > Any experience with the free "VMware vSphere Hypervisor"?. (It was > formerly known as "VMware ESXi Single Server" or "free ESXi".) > > http://www.vmware.com/products/vsphere-hypervisor/overview.html > > I would need a tutorial about that... For example, does that run without > a host OS? Can it be managed only via Win clients? Issues with CentOS > 4/5 guests (all my systems are currently CentOS 4/5). > > - Jussi > > -- > Jussi Hirvi * Green Spot > Topeliuksenkatu 15 C * 00250 Helsinki * Finland > Tel. +358 9 493 981 * Mobile +358 40 771 2098 (only sms) > jussi.hirvi at greenspot.fi * http://www.greenspot.fi > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >
On 27/03/11 11:57, Jussi Hirvi wrote:> Some may be bored with the subject - sorry... > > Still not decided about virtualization platform for my "webhotel v2" > (ns, mail, web servers, etc.). > > KVM would be a natural way to go, I suppose, only it is too bad CentOS 6 > will not be out in time for me - I guess KVM would be more mature in > CentOS 6.I believe KVM was introduced in RHEL5.4, so I presume CentOS5.5 have a working KVM support as well, in addition to Xen. Of course, it will be even better with CentOS6. For the impatient souls, ScientificLinux 6.0 is released - even though, discussions lately in this list raises some concerns regarding how good the binary compatibility is in SL6, compared to CentOS6. This makes me wondering how well it would go to migrate from SL6 to CentOS 6, if all KVM guests are on dedicated/separate LVM volumes and that you take a backup of /etc/libvirt. So when CentOS6 is released, scratch SL6 and install CentOS6, put back the SL6 libvirt configs ... would there be any issues in such an approach? And what about other KVM based host OSes? kind regards, David Sommerseth