Sorry, the directory you need to check is /var/lib/nova/instances. MCo.
On Tue, Dec 4, 2012 at 5:54 PM, Marco CONSONNI <mcocm...@gmail.com> wrote: > Hi Ahmed, > > very technical questions. > I'm not sure my answers are right: I'm just an user... > > In order to answer, I've just look at what happens and made some guess. > Feel free to verify yourself. > > I'm assuming you are using KVM as I'm doing. > > The space for the boot disk and the ephemeral disk should be represented > as files in the physical node where the VM is hosted. > In order to check that, go to directory /var/lib/nova on the node where > the VM is running. > As far as I understand, this is where nova (and KVM) keep the running > instances' information. > You should see a directory for each running instance named as > instance-xxxxxxx, where xxxxxxx uniquely identifies an instance (there are > several ways for uniquely identify an instance, this is one of many... but > this is a different story). > Go into one of these and check what you find. > > For what concerns nova-scheduler, I don't know what exactly does. I'm > afraid that you need to test and see what happens. > > A nova command can help for inspecting what a node is using, in terms of > resources. > > At the controller node (or any other node where you installed nova > client), type the following command substituting OpenStack02 with the name > of the node you want to inspect: > > *$ nova host-describe OpenStack02* > > > +-------------+----------------------------------+-----+-----------+---------+ > > | HOST | PROJECT | cpu | memory_mb | > disk_gb | > > > +-------------+----------------------------------+-----+-----------+---------+ > > | OpenStack02 | (total) | 16 | 24101 | 90 > | > > | OpenStack02 | (used_max) | 13 | 7680 | 0 > | > > | OpenStack02 | (used_now) | 13 | 8192 | 0 > | > > | OpenStack02 | 456ec9d355ae4feebe48a2e79e703225 | 4 | 2048 | 0 > | > > | OpenStack02 | fb434e07b687494bb669fde23f497970 | 9 | 5632 | 0 > | > > > +-------------+----------------------------------+-----+-----------+---------+ > > It return a brief report of the resources currently used by a node. > > To my knowledge, the dashboard does not provide a similar page, at the > time being. > > Hope it helps, > Marco. > > > > > On Tue, Dec 4, 2012 at 4:40 PM, Ahmed Al-Mehdi <ahmedalme...@gmail.com>wrote: > >> Hi Marco, >> >> Thank you very much for the info, much much clearer. I was looking for >> the boot disk using "ls -l /dev/sd*", but the existence of /dev/vda1 >> should have given me a clue. >> >> A few follow up questions: >> >> - I am assuming the space for the VM boot disk is allocated from the >> local hard disk of the physical host on which the VM is instantiated, >> right? >> - If Yes >> - How is the boot disk represented on the physical host. Is it a file >> on the local filesystem that represent the VM boot disk? >> - I am guessing there is some logic in nova-scheduler that checs >> first if there is enough disk apace on the physical host for the VM(along >> with RAM, >> VCPUs) before launching the VM on the host? >> - Is there any way to find out from Horizon how much disk space is >> available on a (or each) physical host for VM boot disk allocation? >> >> Thank you, >> Ahmed. >> >> >> >> >> On Tue, Dec 4, 2012 at 12:07 AM, Marco CONSONNI <mcocm...@gmail.com>wrote: >> >>> Hello, >>> >>> >>> When you use a flavor with an ephemeral disk size different from zero, >>> the instance is booted with an extra virtual disk whose size is indicated >>> by the ephemeral value (in GB). >>> >>> Using cirros image, try a flavor with ephemeral disk size different from >>> zero (you need to create one yourself because the "standard" flavors have >>> ephemeral size equal to 0), then log into the just booted instance and type: >>> >>> >>> *$ ls /dev/vd** >>> >>> /dev/vda /dev/vda1 /dev/vdb >>> >>> >>> >>> Disk /dev/vdb is a (virtual) disk, automatically created at boot time, >>> corresponding to the ephemeral disk space indicated by the flavor . Please >>> note that /dev/vda, mounted as /dev/vda1, is the boot disk, always created >>> when you boot an instance. >>> >>> Verify the size of the available disks; more specifically, verify >>> /dev/vdb: >>> >>> * >>> * >>> >>> *$ sudo fdisk -l* >>> >>> Disk /dev/vda: 1073 MB, 1073741824 bytes >>> >>> 255 heads, 63 sectors/track, 130 cylinders, total 2097152 sectors >>> >>> Units = sectors of 1 * 512 = 512 bytes >>> >>> Sector size (logical/physical): 512 bytes / 512 bytes >>> >>> I/O size (minimum/optimal): 512 bytes / 512 bytes >>> >>> Disk identifier: 0x00000000 >>> >>> >>> >>> Device Boot Start End Blocks Id System >>> >>> /dev/vda1 * 16065 2088449 1036192+ 83 Linux >>> >>> >>> >>> Disk /dev/vdb: 1073 MB, 1073741824 bytes >>> >>> 16 heads, 63 sectors/track, 2080 cylinders, total 2097152 sectors >>> >>> Units = sectors of 1 * 512 = 512 bytes >>> >>> Sector size (logical/physical): 512 bytes / 512 bytes >>> >>> I/O size (minimum/optimal): 512 bytes / 512 bytes >>> >>> Disk identifier: 0x00000000 >>> >>> >>> >>> Disk /dev/vdb doesn't contain a valid partition table >>> >>> >>> >>> Please note that /dev/vdb is made available as raw device, meaning that >>> you need to partition and format it before using. >>> >>> You can find instructions on how to do that here >>> http://docs.openstack.org/folsom/openstack-compute/admin/content/configure-nova-volume.html(search >>> for command fdisk) >>> >>> Also note that this disk, being ephemeral, disappears when you terminate >>> the VM. If you want to keep the data you produce with a VM that is destined >>> to be terminated, you need to use Volumes that you explicitly create and >>> attach using the services implemented by Cinder (former nova-volume). >>> >>> >>> For what concerns the size you define for the boot disk, try and lunch >>> two instances: one with flavor m1.tiny the other with m1.small: >>> >>> >>> -- tiny -- >>> >>> *$ sudo fdisk -l >>> * >>> Disk /dev/vda: 41 MB, 41126400 bytes >>> 255 heads, 63 sectors/track, 5 cylinders, total 80325 sectors >>> Units = sectors of 1 * 512 = 512 bytes >>> Sector size (logical/physical): 512 bytes / 512 bytes >>> I/O size (minimum/optimal): 512 bytes / 512 bytes >>> Disk identifier: 0x00000000 >>> >>> Device Boot Start End Blocks Id System >>> /dev/vda1 * 16065 80324 32130 83 Linux >>> >>> >>> -- small -- >>> >>> >>> *$ sudo fdisk -l >>> * >>> Disk /dev/vda: 21.5 GB, 21474836480 bytes >>> 255 heads, 63 sectors/track, 2610 cylinders, total 41943040 sectors >>> Units = sectors of 1 * 512 = 512 bytes >>> Sector size (logical/physical): 512 bytes / 512 bytes >>> I/O size (minimum/optimal): 512 bytes / 512 bytes >>> Disk identifier: 0x00000000 >>> >>> Device Boot Start End Blocks Id System >>> /dev/vda1 * 16065 41929649 20956792+ 83 Linux >>> >>> >>> As you notice, the size indicated by the flavor has effects on the size >>> of the boot disk. >>> >>> >>> Hope it helps, >>> Marco. >>> >>> >>> >>> >>> On Mon, Dec 3, 2012 at 7:03 PM, Ahmed Al-Mehdi >>> <ahmedalme...@gmail.com>wrote: >>> >>>> Hello, >>>> >>>> I instantiated a VM using the cirros image, using the pre-defined >>>> "m1.small" (1 VCPU, 2 GB Ram, 20G boot disk, 0 Ephemeral disk). I then >>>> logged into the console of the VM to view some system stats. The num of >>>> CPU and memory makes sense, but I am a bit confused on the storage aspect. >>>> I see the output of "df -h " as following: >>>> >>>> $ df -h >>>> Filesystem Size Used Available >>>> Use% Mounted on >>>> /dev 1001.1M 0 1001.1M >>>> 0% /dev >>>> /dev/vda1 23.2M 12.9M 9.1M >>>> 59% / >>>> tmpfs 1004.1M 0 1004.1M >>>> 0% /dev/shm >>>> tmpfs 200.0K 20.0K 180.0K >>>> 10% /run >>>> >>>> >>>> What is the difference between Boot disk and Ephemeral disk? >>>> >>>> How can I correlate the 20G boot disk to the output of "df -h". >>>> >>>> >>>> Regards, >>>> Ahmed. >>>> >>>> >>>> _______________________________________________ >>>> Mailing list: https://launchpad.net/~openstack >>>> Post to : openstack@lists.launchpad.net >>>> Unsubscribe : https://launchpad.net/~openstack >>>> More help : https://help.launchpad.net/ListHelp >>>> >>>> >>> >> >
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