Zbigniew Jędrzejewski-Szmek
2013-Nov-14 23:32 UTC
is mounting subvolumes with a read-only root subvolume allowed?
Hi,
I have a box with / and /home being subvolumes from the same btrfs filesystem.
/etc/fstab:
UUID=c0686... / btrfs subvol=root,x-systemd.device-timeout=0 1 1
UUID=c0686... /home btrfs subvol=home,x-systemd.device-timeout=0 1 1
...
/ is initially mounted readonly by the initramfs, and then after switching
to the real system, /home is attempted to be mounted in parallel with /
being remounted rw. If remounting rw happens first, boot proceeds. If
mounting /home is attempted to realy, it fails.
$ /bin/mount /home
mount: /dev/mapper/luks-765... is already mounted or /home busy
/dev/mapper/luks-765... is already mounted on /
$ /bin/mount -o remount,rw /
$ /bin/mount /home
$
So, is this expected that the other subvolume must be mounted rw?
Zbyszek
Karel Zak
2013-Nov-14 23:43 UTC
Re: is mounting subvolumes with a read-only root subvolume allowed?
On Fri, Nov 15, 2013 at 12:32:10AM +0100, Zbigniew Jędrzejewski-Szmek wrote:> Hi, > I have a box with / and /home being subvolumes from the same btrfs filesystem. > > /etc/fstab: > UUID=c0686... / btrfs subvol=root,x-systemd.device-timeout=0 1 1 > UUID=c0686... /home btrfs subvol=home,x-systemd.device-timeout=0 1 1 > ... > > / is initially mounted readonly by the initramfs, and then after switching > to the real system, /home is attempted to be mounted in parallel with / > being remounted rw. If remounting rw happens first, boot proceeds. If > mounting /home is attempted to realy, it fails. > > $ /bin/mount /home > mount: /dev/mapper/luks-765... is already mounted or /home busy > /dev/mapper/luks-765... is already mounted on / > $ /bin/mount -o remount,rw / > $ /bin/mount /home > $ > > So, is this expected that the other subvolume must be mounted rw?This is known and pretty stupid issue: http://www.spinics.net/lists/linux-btrfs/msg25502.html ... but it seems that btrfs guys are fine with this "feature". Karel -- Karel Zak <kzak@redhat.com> http://karelzak.blogspot.com _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Zbigniew Jędrzejewski-Szmek
2013-Nov-15 00:04 UTC
Re: [systemd-devel] is mounting subvolumes with a read-only root subvolume allowed?
On Fri, Nov 15, 2013 at 12:43:51AM +0100, Karel Zak wrote:> On Fri, Nov 15, 2013 at 12:32:10AM +0100, Zbigniew Jędrzejewski-Szmek wrote: > > Hi, > > I have a box with / and /home being subvolumes from the same btrfs filesystem. > > > > /etc/fstab: > > UUID=c0686... / btrfs subvol=root,x-systemd.device-timeout=0 1 1 > > UUID=c0686... /home btrfs subvol=home,x-systemd.device-timeout=0 1 1 > > ... > > > > / is initially mounted readonly by the initramfs, and then after switching > > to the real system, /home is attempted to be mounted in parallel with / > > being remounted rw. If remounting rw happens first, boot proceeds. If > > mounting /home is attempted to realy, it fails. > > > > $ /bin/mount /home > > mount: /dev/mapper/luks-765... is already mounted or /home busy > > /dev/mapper/luks-765... is already mounted on / > > $ /bin/mount -o remount,rw / > > $ /bin/mount /home > > $ > > > > So, is this expected that the other subvolume must be mounted rw? > > This is known and pretty stupid issue: > http://www.spinics.net/lists/linux-btrfs/msg25502.html > > ... but it seems that btrfs guys are fine with this "feature".5 months without a reply. Great. Zbyszek -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html