Hi there . I just come up with the need to migrate my LVM to zfs , when using LVM I was able to reference my LV partitions as /dev/VG/LV, then within the configuration file I could reference the device as phy:/dev/VG/LV, now with zfs I''ve got my disk and the pools as in , mypool/storage1,2,3 and so on. Now my question is. I did not find any /dev/ reference to point to in the configuracion file as in solaris, like /dev/zvol, so, should I create an image file and then install? Will that methood downgrade my I/O performance or will that be handled bu the access methood I use? iSCSI, SAN Storage, Disk Type, HBA, network speed and so on. Anyone already installed the combination of -> DomU+ZFS+Debian? Ideas, suggestions? Thanks in advance Best Regards , thanks for your time and support. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Wed, Sep 14, 2011 at 10:50 AM, Net Warrior <netwarrior863@gmail.com> wrote:> Hi there . > > I just come up with the need to migrate my LVM to zfs ,Is this zfs-fuse, zfsonlinux, or did you switch the dom0 to opensolaris, or did you have separate storage server with zfs?> when using LVM I was > able to reference my LV partitions as /dev/VG/LV, then within the > configuration file I could reference the device as phy:/dev/VG/LV, now with > zfs I''ve got my disk and the pools as in , mypool/storage1,2,3 and so on. > > Now my question is. > > I did not find any /dev/ reference to point to in the configuracion file as > in solaris, like /dev/zvol, so, should I create an image file and then > install?zfs-fuse does not support zvols, and it''s not recommended to store VM images as files (trust me, I tried). With zfsonlinux you WILL have /dev/zvol/mypool/storage1. That is, assuming you either use Ubuntu ppa or latest source from git to install zfsonlinux.> Will that methood downgrade my I/O performance or will that be handled bu > the access methood I use? iSCSI, SAN Storage, Disk Type, HBA, network speed > and so on.Roughly speaking, on the same hardware, using file image on zfs or zvol, will make i/o performance drop by 50-75% compared to plain LVM. Again, this is ROUGHLY based on my past tests. YMMV.> Anyone already installed the combination of -> DomU+ZFS+Debian?I have a dev system with xen+zvol+RHEL, as well as another one with xen+zfs-fuse+RHEL. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks for your answer, I have two scenarios. One local server for testing purposes using zfs. A SAN. I think I will move forward with something like this, disk=[ ''iscsi:2011-09.us.example:server,xvda,w'', ] Do you think is this much more reasonable? I think that for the local server that will be much better than using images, do you agree? Thank you very much. Regards El 09/14/2011 01:03 AM, Fajar A. Nugraha escribió:> On Wed, Sep 14, 2011 at 10:50 AM, Net Warrior<netwarrior863@gmail.com> wrote: >> Hi there . >> >> I just come up with the need to migrate my LVM to zfs , > Is this zfs-fuse, zfsonlinux, or did you switch the dom0 to > opensolaris, or did you have separate storage server with zfs? > >> when using LVM I was >> able to reference my LV partitions as /dev/VG/LV, then within the >> configuration file I could reference the device as phy:/dev/VG/LV, now with >> zfs I''ve got my disk and the pools as in , mypool/storage1,2,3 and so on. >> >> Now my question is. >> >> I did not find any /dev/ reference to point to in the configuracion file as >> in solaris, like /dev/zvol, so, should I create an image file and then >> install? > zfs-fuse does not support zvols, and it''s not recommended to store VM > images as files (trust me, I tried). > > With zfsonlinux you WILL have /dev/zvol/mypool/storage1. That is, > assuming you either use Ubuntu ppa or latest source from git to > install zfsonlinux. > >> Will that methood downgrade my I/O performance or will that be handled bu >> the access methood I use? iSCSI, SAN Storage, Disk Type, HBA, network speed >> and so on. > Roughly speaking, on the same hardware, using file image on zfs or > zvol, will make i/o performance drop by 50-75% compared to plain LVM. > Again, this is ROUGHLY based on my past tests. YMMV. > >> Anyone already installed the combination of -> DomU+ZFS+Debian? > I have a dev system with xen+zvol+RHEL, as well as another one with > xen+zfs-fuse+RHEL. >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Wed, Sep 14, 2011 at 11:12 AM, Net Warrior <netwarrior863@gmail.com> wrote:> Thanks for your answer, > > I have two scenarios. > One local server for testing purposes using zfs. > A SAN. > > I think I will move forward with something like this, disk=[ > ''iscsi:2011-09.us.example:server,xvda,w'', ] > Do you think is this much more reasonable? > I think that for the local server that will be much better than using > images, do you agree?Some aspects of that: (1) file vs block (2) Linux LVM vs zvol (3) Local vs SAN (iscsi or whatever) For (1), the usual answer is "it depends". block is usually better for high load, but for some types of load and images file-backed can perform better due to thin-provisioning and cache For (2), if your ONLY concern is performance, with the same resources LVM will win by huge margin. No brainer really. Just like ext4 will have higher performance compared to zfs or btrfs. But if you want to use zfs/zvol, I assume you already know about its features and performance. For (3), with the same resource (e.g. same number of disks), local usually have high performance compare to SAN. Then again the resources is usually NOT the same (e.g. a SAN is usually designed to have better tiering with cache and such to provide better performance). -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users