Re: [CentOS] Vitualization and Partitioning
On Tue, Sep 13, 2011 at 1:52 AM, Thomas Dukes tdu...@sc.rr.com wrote: -Original Message- From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On Behalf Of ken Sent: Monday, September 12, 2011 12:36 AM To: CentOS mailing list Subject: Re: [CentOS] Vitualization and Partitioning On 09/11/2011 11:10 PM Emmanuel Noobadmin wrote: Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I like LVM (for the reasons you cite). Would you (anyone?) say it's best to have one LV per guest or one LV for all guests? tnx. I'm new to this but I would think you would want a separate LV for each guest. Seems I read somewhere, that you need one core per guest as well. That's why I'm opting for the Xeon processor rather than the iCore(x). Four cores v. two. More options. Can't believe this thread hasn't stirred more response. Maybe we all are in the learning phase. Eddie ___ We use LVM on all our virtual hosting servers since it's much easier to manage. You basically setup a PV volume spanning the whole drive(s), and then a 10GB (or larger if you need to) LVM volume for /root, 10GB for /var, 2GB for /tmp 5GB for /home. Then for any VM's just add LVM volumes as needed, for example: /dev/Volume001/vm1_root - 10GB /dev/Volume001/vm1_swap - 1GB Another tip: Don't use the default LVM volume naming scheme, but instead name the LVM volumes according to your server name, i.e. server01 server02. This way if server01's HDD crashes and you need to mount it on server002 for recovery purposes, you won't have conflicting LVM volumes -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
On Tue, Sep 13, 2011 at 2:00 PM, Rudi Ahlers r...@softdux.com wrote: On Tue, Sep 13, 2011 at 1:52 AM, Thomas Dukes tdu...@sc.rr.com wrote: -Original Message- From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On Behalf Of ken Sent: Monday, September 12, 2011 12:36 AM To: CentOS mailing list Subject: Re: [CentOS] Vitualization and Partitioning On 09/11/2011 11:10 PM Emmanuel Noobadmin wrote: Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I like LVM (for the reasons you cite). Would you (anyone?) say it's best to have one LV per guest or one LV for all guests? tnx. I'm new to this but I would think you would want a separate LV for each guest. Seems I read somewhere, that you need one core per guest as well. That's why I'm opting for the Xeon processor rather than the iCore(x). Four cores v. two. More options. Can't believe this thread hasn't stirred more response. Maybe we all are in the learning phase. Eddie ___ We use LVM on all our virtual hosting servers since it's much easier to manage. You basically setup a PV volume spanning the whole drive(s), and then a 10GB (or larger if you need to) LVM volume for /root, 10GB for /var, 2GB for /tmp 5GB for /home. Then for any VM's just add LVM volumes as needed, for example: /dev/Volume001/vm1_root - 10GB /dev/Volume001/vm1_swap - 1GB Another tip: Don't use the default LVM volume naming scheme, but instead name the LVM volumes according to your server name, i.e. server01 server02. This way if server01's HDD crashes and you need to mount it on server002 for recovery purposes, you won't have conflicting LVM volumes Hi, Interesting subject. Let me participate too. Suppose we are going to install 3 VMs, I think it is proper to create separate LVMs like this /dev/vg_server1/lv.server1 and mount it as /var/lib/libvirt/images/server1 /dev/vg_server2/lv.server2 and mount it as /var/lib/libvirt/images/server2 /dev/vg_server3/lv.server3 and mount it as /var/lib/libvirt/images/server3 If I mount in that way, Is it possible to take live snapshot backup while these 2 servers are running? Hope to hear from you.. -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Thank you Indunil Jayasooriya ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
On 09/13/2011 12:38 PM, Indunil Jayasooriya wrote: On Tue, Sep 13, 2011 at 2:00 PM, Rudi Ahlersr...@softdux.com wrote: On Tue, Sep 13, 2011 at 1:52 AM, Thomas Dukestdu...@sc.rr.com wrote: -Original Message- From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On Behalf Of ken Sent: Monday, September 12, 2011 12:36 AM To: CentOS mailing list Subject: Re: [CentOS] Vitualization and Partitioning On 09/11/2011 11:10 PM Emmanuel Noobadmin wrote: Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I like LVM (for the reasons you cite). Would you (anyone?) say it's best to have one LV per guest or one LV for all guests? tnx. I'm new to this but I would think you would want a separate LV for each guest. Seems I read somewhere, that you need one core per guest as well. That's why I'm opting for the Xeon processor rather than the iCore(x). Four cores v. two. More options. Can't believe this thread hasn't stirred more response. Maybe we all are in the learning phase. Eddie ___ We use LVM on all our virtual hosting servers since it's much easier to manage. You basically setup a PV volume spanning the whole drive(s), and then a 10GB (or larger if you need to) LVM volume for /root, 10GB for /var, 2GB for /tmp 5GB for /home. Then for any VM's just add LVM volumes as needed, for example: /dev/Volume001/vm1_root - 10GB /dev/Volume001/vm1_swap - 1GB Another tip: Don't use the default LVM volume naming scheme, but instead name the LVM volumes according to your server name, i.e. server01 server02. This way if server01's HDD crashes and you need to mount it on server002 for recovery purposes, you won't have conflicting LVM volumes Hi, Interesting subject. Let me participate too. Suppose we are going to install 3 VMs, I think it is proper to create separate LVMs like this /dev/vg_server1/lv.server1 and mount it as /var/lib/libvirt/images/server1 /dev/vg_server2/lv.server2 and mount it as /var/lib/libvirt/images/server2 /dev/vg_server3/lv.server3 and mount it as /var/lib/libvirt/images/server3 Don't use separate volume groups. Also don't mount the logical volumes but instead use them directly as block devices. That should give you better performance as the i/o path is then VM-block device instead of VM-filesystem-block device. If I mount in that way, Is it possible to take live snapshot backup while these 2 servers are running? Remember that you need to allocate enough space for the snapshot volume to contain all the blocks that change on the VM while the backup is running i.e. if your backup is running for an hour and during that hour your VM receives 2G worth of writes/update then you need to have at least a size of 2G for your snapshot volume. This also means that you have to reserve enough space in the volume group to create a big enough snapshot volume. Also keep in mind that the backup you will get will not be fully consistent only crash consistent. Regards, Dennis ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
On Tue, Sep 13, 2011 at 10:31 AM, Trey Dockendorf treyd...@gmail.com wrote: That considered I saw no benefit in my case to use LVM when some other tools could combine the ability to do both qcow2 and memory snapshotting at once. Could you kindly share with us the tools you which could do both? Another (may unrelated) question: Has anybody installed or migrated a Netware 3.12 using KVM? If so, can you please share the experiences? especially bits about Netware partitioning and the NIC model that needs to be selected? TIA -- Regards, Rajagopal ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
On Tue, Sep 13, 2011 at 11:57 AM, Rajagopal Swaminathan raju.rajs...@gmail.com wrote: On Tue, Sep 13, 2011 at 10:31 AM, Trey Dockendorf treyd...@gmail.com wrote: That considered I saw no benefit in my case to use LVM when some other tools could combine the ability to do both qcow2 and memory snapshotting at once. Could you kindly share with us the tools you which could do both? Another (may unrelated) question: Has anybody installed or migrated a Netware 3.12 using KVM? If so, can you please share the experiences? especially bits about Netware partitioning and the NIC model that needs to be selected? TIA -- Regards, Rajagopal ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos I've only successfully tested using virt-manager to do snapshots. There is a way using virsh, doing snapshot-create domain, but I receive an error due to lack of that feature. error: internal error unable to execute QEMU command 'savevm': The command savevm has not been found Using the virsh save command works, but only does it without shutting down the VM if done through virt-manager. Other tools that look promising for snapshots thus far are things like Convirt, OpenQRM, and Archipel, but I have yet to get them in production to test that out. - Trey ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
-Original Message- From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On Behalf Of ken Sent: Monday, September 12, 2011 12:36 AM To: CentOS mailing list Subject: Re: [CentOS] Vitualization and Partitioning On 09/11/2011 11:10 PM Emmanuel Noobadmin wrote: Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I like LVM (for the reasons you cite). Would you (anyone?) say it's best to have one LV per guest or one LV for all guests? tnx. I'm new to this but I would think you would want a separate LV for each guest. Seems I read somewhere, that you need one core per guest as well. That's why I'm opting for the Xeon processor rather than the iCore(x). Four cores v. two. More options. Can't believe this thread hasn't stirred more response. Maybe we all are in the learning phase. Eddie ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
On Mon, Sep 12, 2011 at 6:52 PM, Thomas Dukes tdu...@sc.rr.com wrote: -Original Message- From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On Behalf Of ken Sent: Monday, September 12, 2011 12:36 AM To: CentOS mailing list Subject: Re: [CentOS] Vitualization and Partitioning On 09/11/2011 11:10 PM Emmanuel Noobadmin wrote: Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I like LVM (for the reasons you cite). Would you (anyone?) say it's best to have one LV per guest or one LV for all guests? tnx. I'm new to this but I would think you would want a separate LV for each guest. Seems I read somewhere, that you need one core per guest as well. That's why I'm opting for the Xeon processor rather than the iCore(x). Four cores v. two. More options. Can't believe this thread hasn't stirred more response. Maybe we all are in the learning phase. Eddie ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos An LV per guest isn't necessary, but has its benefits. What I did on one of my server was a use two drives in RAID 1 for the system and then a RAID 6 array for the VM storage. I've opted to use QCow2 images for the virtual disks, so they all go on a LV I created /vmstore where all virtual disks go. I always try to keep the system paritions (/ and /boot) separate from the data (with virtual server, I use /vmstore , or /var/lib/libvirt/images) at least logically, if not physically. My biggest consideration between LVM and image files for the VM disks was snapshot capabilities. While LVM can do snapshots using lvm's native tools, it still requires extra steps to get the VM's memory (if still running). That considered I saw no benefit in my case to use LVM when some other tools could combine the ability to do both qcow2 and memory snapshotting at once. Plus in my environment it is easier to work with a single virtual disk file than deal with LVMs. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I may combine my windoze XP on the CentOS machine so would I need to create a partition and format that at installation? If I decide to wait and go with Windoze 7 can I still create the partition later? I would like a partition scheme that allows for easier upgrades or installs without losing data. Try using LVM then, it allows you to create and resize logical partitions, including expanding with additional hard disks in the future without having to reconfigure your VM guest (except the usual file system expansion steps) Thanks, I'm more confused now that when I started reading about this stuf.. That's my experience too, the more we read, the more alternatives/options there are, the more confusing it gets! :D ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Vitualization and Partitioning
On 09/11/2011 11:10 PM Emmanuel Noobadmin wrote: Hi, When I do the install, do I or should I setup a separate partition for guest That would be better from a performance point of view OS's? From the redhat docs, it looks like the guest OS's reside at /var/lib/libvirt/images/. This should be using files as disk files, which I did and found it to be a problem when there is heavy I/O. I like LVM (for the reasons you cite). Would you (anyone?) say it's best to have one LV per guest or one LV for all guests? tnx. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
