much appreciated simon! On Tue, Mar 14, 2017 at 11:13 PM, Simon Fels <[email protected]> wrote:
> On 15.03.2017 00:39, Manik Taneja wrote: > > hi there, > > > > an interesting question came up on askubuntu- > > > > https://askubuntu.com/questions/888404/ubuntu-core-with-raid-1?rq=1 > > > > is the best solution to package mdadm as a snap with core providing > > an interface to /dev/md*? are there alternate solutions? > > We had a pretty active discussion a while back when we implemented the > udisks2 interface in snapd. The outcome was that we don't want to give > arbitrary snaps access to block devices and added all access for those > directly into the udisks2 interface (see [0]). > > udisks2 offers a mediated way for all other snaps to deal with block > devices and generally also allows working with RAIDs. I say generally, > because this is a feature we didn't verified yet that it is working with > the udisks2 snap currently in the store. > > If support for RAIDs in udisks2 works users should be able to mount a > RAID on a directory in /media via an dbus API call. > > One downside is that the udisks2 interface explicitly denies plug > connections as it still gives kind of privileged access to the system. > Every mount done via udisks2 will appear below /media and every snap > using the removable-media interface will get access to devices mounted > there, regardless if it's the system partition or not. So even the plug > side is a very privileged thing. That said, snaps can ask for a > snap-declaration on the store side to get connections to udisks2. > > Another feature we support with the udisks2 snap is auto-mounting. This > allows a device to say that it wants removable devices like USB storage > device to be automatically mounted in /media as you know it from > consumer oriented devices like the Ubuntu Desktop. Depending on how the > RAID is setup this might be able to get the the RAID mounted on boot > into /media. Requirements for the automounter to consider a device are > currently: > > * Device is not a system device (meaning its not a partition on the > device we're booting the system from) > * Device is not already mounted > * Device is a removable devices (USB, CD/DVD) > > For a very simple, unconfined solution you could just install the > udisks2 snap (given that it detects and works well with RAID devices) > and create a systemd unit in /etc/systemd/system/mount-my-raid.service > > [Unit] > Description=Mount my RAID > > [Service] > Exec=/snap/bin/udisks2.udisksctl mount -b /path/to/block/device > > [Install] > WantedBy=multi-user.target > > Then activate it via > > $ sudo systemctl enable mount-my-raid.service > > and the RAID should be automatically mounted below /media on the next > system reboot. > > I hope this helps. > > Btw. I will post this as an answer to the askubuntu.com question too. > > regards, > Simon > > > [0]: > https://github.com/snapcore/snapd/blob/master/interfaces/ > builtin/udisks2.go > > -- > Snapcraft mailing list > [email protected] > Modify settings or unsubscribe at: https://lists.ubuntu.com/ > mailman/listinfo/snapcraft > -- Snapcraft mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/snapcraft
