> On 21 Dec 2016, at 16:26, Martin Sivak <msivak(a)redhat.com&gt; wrote: > > Hi, > >> Hope this get's in. This seems less overhead than a complete >> hyperconverged gluster setup. > > But NFS still is a single point of failure. Hyperconverged is supposed > to address that. > >>> In order to improve performance, disk I/O bound VMs can be pinned to >>> a host with local storage. However there still is a performance >>> drawback of NFS layers. Treating a local NFS storage as a local storage >>> improves performance for VMs pinned to host. > > So VMs on one host will get better IO performance and the others will > still use NFS as they do now. > > It is an interesting idea, I am just not sure if having poor-man's > hyperconverged setup with all the drawbacks of NFS is worth it. > Imagine for example what happens when that storage provider host needs > to be fenced or put into maintenance. The whole cluster would go down > (all VMs would lose storage connection, not just the VMs from the > affected host). > > I will let someone from the storage team to respond to this, but I do > not think that trading performance (each host has its own local > storage) and resilience (well, at least one failing host does not > affect the others) for migrations is a good deal. If disk performance is critical then there is an option to use direct access on local host using either PCI passthrough of a local storage controller or SCSI passthrough of LUNs. > > -- > Martin Sivak > SLA / oVirt > >> On Wed, Dec 21, 2016 at 2:18 PM, Sven Kieske <s.kieske(a)mittwald.de&gt; wrote: >>> On 21/12/16 11:44, Pavel Gashev wrote: >>> Hello, >>> >>> I'd like to introduce a RFE that allows to use a local storage in multi >>> server environments https://bugzilla.redhat.com/ show_bug.cgi?id=1406412 >>> >>> Most servers have a local storage. Some servers have very reliable >>> storages with hardware RAID controllers and battery units. >>> >>> Example user cases: >>> https://www.mail-archive.com/users@ovirt.org/msg36719.html >>> https://www.mail-archive.com/users@ovirt.org/msg36772.html >>> >>> The best way to use local storage in multi server "shared" datacenters >>> is exporting it over NFS. Using NFS allows to move disks and VMs among >>> servers. >>> >>> In order to improve performance, disk I/O bound VMs can be pinned to >>> a host with local storage. However there still is a performance >>> drawback of NFS layers. Treating a local NFS storage as a local storage >>> improves performance for VMs pinned to host. >>> >>> Currently setting up of NFS exports is out of scope of oVirt. However >>> this would be a way to get rid of "Local/Shared" storage types of >>> datacenter. So that all storages are shared, but local storages are >>> used as local. >>> >>> Any questions/comments are welcome. >>> >>> Specifically I'd like to request for comment on potential data >>> integrity issues during online VM or disk migration between NFS and >>> localfs. >>> >> >> Just let me say that I really like this as an end user. >> >> Hope this get's in. This seems less overhead than a complete >> hyperconverged gluster setup. >> >> >> -- >> Mit freundlichen Grüßen / Regards >> >> Sven Kieske >> >> Systemadministrator >> Mittwald CM Service GmbH & Co. KG >> Königsberger Straße 6 >> 32339 Espelkamp >> T: +495772 293100 >> F: +495772 293333 >> https://www.mittwald.de >> Geschäftsführer: Robert Meyer >> St.Nr.: 331/5721/1033, USt-IdNr.: DE814773217, HRA 6640, AG Bad Oeynhausen >> Komplementärin: Robert Meyer Verwaltungs GmbH, HRB 13260, AG Bad Oeynhausen >> >> >> _______________________________________________ >> Devel mailing list >> Devel(a)ovirt.org >> http://lists.ovirt.org/mailman/listinfo/devel > _______________________________________________ > Devel mailing list > Devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/devel > > _______________________________________________ Devel mailing list Devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/devel

On 22 Dec 2016, at 16:12, Pavel Gashev <Pax(a)acronis.com&gt; wrote: Michal, VMs with attached devices are bound to host. When I use NFS I can migrate my VM and disks to another host.

On Wed, 2016-12-21 at 19:03 +0100, Michal Skrivanek wrote: > > If disk performance is critical then there is an option to use direct > access on local host using either PCI passthrough of a local storage > controller or SCSI passthrough of LUNs. >