Hello Patrick, Here are some questions i received in private, but i think is worth replying to the mailing list.
On 22 February 2014 03:30, Patrick H. <[email protected]> wrote: > Is there support for dmraid5? Can I test this on an alpha build? Is the > project page in github or launchpad. > Ubuntu is a distribution and dmraid and mdadm are packages of thereof. So patches for all the work so far are uploaded into Ubuntu Archive. https://launchpad.net/ubuntu/+source/dmraid 1.0.0.rc16-4.2ubuntu3 or better https://launchpad.net/ubuntu/+source/mdadm 3.2.5-5ubuntu3 or better > I have been using dmraid since 10.04 or before. It's been a few years that I > have been running the same Intel Matrix Raid5 with the optional raid45 > kernel module. I want to test this migration from dmraid to mdadm before the > 14.04 release comes out. > Note that above dmraid package drops usage of raid45 module, and instead uses stock and widely available dm-raid modules. If you wish to try out mdadm, you'll need to install mdadm package i've linked above, comment out /etc/default/grub.d/dmraid2mdadm.cfg, update references to correct devices as per original email and update initramfs, Regards, Dimitri. > > On Fri, Feb 21, 2014 at 8:57 PM, Steve Langasek <[email protected]> > wrote: >> >> Hi Dimitri, >> >> On Thu, Feb 20, 2014 at 03:49:28PM +0000, Dimitri John Ledkov wrote: >> > This cycle a few things were done in mdadm & dmraid packages to >> > prepare for transition from dmraid to mdadm for a few formats that >> > mdadm supports. >> >> > At the moment it trusty, mdadm has full support to assemble Intel >> > Matrix Raid and DDF fakeraid arrays, instead of dmraid. At the moment >> > however, mdadm codepath is disable via a kernel cmdline options >> > (nomdmonddf nomdmonisw) and thus if both mdadm and dmraid are present >> > in the initramfs dmraid will complete assembly. With or without kernel >> > options, dmraid completes assembly if mdadm is not present. Thus >> > existing upgrades continue to work as they are. >> >> > However to complete the upgrade, i would like remove the feature flag >> > and enable mdadm based assembly, such that installing mdadm migrates >> > systems using dmraid for Intel Matrix Raid and DDF fakeraids to mdadm. >> >> > But further changes are required, as the device names change when >> > moving from dmraid to mdadm, e.g.: >> >> > dmraid names: >> > * /dev/mapper/isw_cbhjgfachh_Volume1 >> > * /dev/mapper/isw_cbhjgfachh_Volume1p1 >> > * /dev/mapper/isw_cbhjgfachh_Volume1p2 >> > * /dev/mapper/isw_cbhjgfachh_Volume1p3 >> >> > become under mdadm: >> > * /dev/md/Volume1 >> > * /dev/md/Volume1p1 >> > * /dev/md/Volume1p2 >> > * /dev/md/Volume1p3 >> >> > Thus changes to /etc/fstab, and/or bootloader are required to look for >> > new places. >> >> > The question I have, is whether such migration should be done >> > automatically or left in the hands of the administrator (e.g. if mdadm >> > is not installed, dist-upgrade is performed no changes are required >> > and dmraid is continued to be used. If one installs mdadm, one would >> > also need to either disable mdadm-fakeraid assembly with kernel >> > cmdline options or adjust /etc/fstab & grub for the new names). >> >> I think we should definitely prefer such migration to be handled >> automatically. >> >> Have a look at the linux-base package in Debian: the postinst has been >> dropped from the Ubuntu package, but in Debian this is the package which >> handled the migration from /dev/hda to UUIDs. It's the logical place to >> insert other device name migrations, though it clearly would need some >> updating for new bootloader packages (FSVO "new" that includes "grub2" ;). >> Perhaps since this migration is specific to dmraid and mdadm it would make >> sense to move the migration code to mdadm itself, but hopefully this at >> least makes for a good starting point. >> >> Hope that helps, >> -- >> Steve Langasek Give me a lever long enough and a Free OS >> Debian Developer to set it on, and I can move the world. >> Ubuntu Developer http://www.debian.org/ >> [email protected] [email protected] >> >> -- >> ubuntu-devel mailing list >> [email protected] >> Modify settings or unsubscribe at: >> https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel >> > -- ubuntu-devel mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
