Re: [Users] oVirt Python SDK: getting the full filenames of disk images

Just make sure you are not changing anything that might cause a splitbrain between the engine database and the actual image set on the storage, those are usually tricky to debug and fix On Thu, Dec 12, 2013 at 4:32 AM, Исаев Виталий Анатольевич <isaev(a)fintech.ru > Dan, thank you for a nice advice. I have forgotten about domxml rich > opportunities… > > > > Vitaly Isaev > > Software engineer > > Information security department > > Fintech JSC, Moscow, Russia > > > > *From:* Dan Yasny [mailto:dyasny@gmail.com] > *Sent:* Monday, December 09, 2013 8:14 PM > > *To:* Исаев Виталий Анатольевич > *Cc:* users(a)ovirt.org > *Subject:* Re: [Users] oVirt Python SDK: getting the full filenames of > disk images > > > > Please see reply inline > > > > On Mon, Dec 9, 2013 at 12:03 AM, Исаев Виталий Анатольевич < > isaev(a)fintech.ru> > Hi Dan, glad to meet you both on LOR and in this mailing list :) > > > > I know, I'm everywhere :) > > > > > > Unfortunately ovirtsdk.infrastructure.brokers.<anything> classes instances > miss information about the higher objects very often. The typical situation > is returning of empty string when we ask something about the parent from > the child object ("child" and "parent" in terms Red Hat Enterprise > Virtualization objects hierarchy). Consider this Python code: > > > > from ovirtsdk.api import API > > from ovirtsdk.xml import params > > ... > > api = API(...) > > d = api.vms.list()[i].get_disks().list()[i] > # > ovirtsdk.infrastructure.brokers.VMDisk class instance, i – any number in > range(api.vms.list().__len__()) > > s = d.get_storage_domains().get_storage_domain()[0] > # ovirtsdk.infrastructure.params.StorageDomain class instance > > t = > s.get_data_center() > # NoneType > > > > So you can see that this approach does not work here. > > > > > > I hope Michael or Itamar can shed some more light on this part, I don't > have a system in front of me to check. AFAIR some objects aren't linked > directly and you simply need to know how to get to them, I've had plenty of > help from Michael before, when I was running a seemingly correct script, > and getting no data, simply because I didn't understand the way the API > looks for objects and relationships. > > > > Our purpose is checking the VM’s disk image integrity (I mean integrity > of system files, stored in /boot, /bin, /sbin, /lib etc.) every time the VM > starts. The integrity checking script is written in Python and relies on > libguestfs and vdsm hooks. Specific vdsm hook runs our script and block the > VM’s boot process until the correctness of the system files hash sums will > be checked. But libguestfs requires the full path to the disk to be > handled, and it’s not integrated with ovirt infrastructure. And here we > face with a task of full disk image filenames definition. > > > > I assume you are using before_vm_start? This will catch the VM > definitions, as passed by the engine, and allow you to reassemble the > domxml. You can get the disk path from the domxml directly, bypassing the > engine APIs completely. > > The problem however, if you are doing this on block storage, is that the > right LV will not be prepared for use by vdsm at this point, so you'll have > to make it accessible manually, then disable access and let vdsm do it's > job. Much easier with NFS/Gluster of course. > > > > > > > > Thank you, > > Vitaly Isaev > > Software engineer > > Information security department > > Fintech JSC, Moscow, Russia > > > > *From:* Dan Yasny [mailto:dyasny@gmail.com] > *Sent:* Friday, December 06, 2013 8:56 PM > *To:* Исаев Виталий Анатольевич > *Cc:* users(a)ovirt.org > *Subject:* Re: [Users] oVirt Python SDK: getting the full filenames of > disk images > > > > Probably not, but you can > > - get the disk image UUID (that's the name in the filesystem or LV name), > > - get the UUID of the storage domain (that will be the top level dir name > or VG name) > > - get the DC UUID (this will be the top level dir name and the mount point > for LVM) > > > > Then compose the path out of these. Keep in mind that the disk UUID you > get is the latest leaf in a snapshot tree, and if you need the entire chain > of images, you need to recursively traverse the tree starting at the leaf, > using the PUUID tag to find the parent. > > > > Might be a better way, but I'm not aware of it. > > > > Moreover, if you explain why you need to touch those images manually > instead of letting ovirt handle everything, we might be able to suggest a > better way > > > > -- > > D > > > > On Wed, Dec 4, 2013 at 2:34 AM, Исаев Виталий Анатольевич < > isaev(a)fintech.ru> > Dear ovirt-engine users, > > > > I will be appreciated if someone experienced in oVirt Python SDK could > advice the method of getting the full filename of the VM’s disk images in > the RHEV hypervisor’s file system. Can I get filename with a full file > system path from a ovirtsdk.infrastructure.brokers.VMDisk class instance? > > > > If Python SDK (what is preffered) can’t provide such an information, may > be it is still possible with RHEV-M REST API? > > > > Thank you, > > Vitaly Isaev > > Software engineer > > Information security department > > Fintech JSC, Moscow, Russia > > > > > _______________________________________________ > Users mailing list > Users(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > > > > >