Comment 8 for bug 1648561

------- Comment From <email address hidden> 2017-01-13 03:54 EDT-------
(In reply to comment #21)
> I'm claiming this bug for myself since I know about os-prober and have other
> grub/os-prober updates in flight. Targetting to ubuntu-17.01.
>
> Is this HTX thing doing read/write operations directly on the disk, or does
> it use a filesystem? Is it using a known filesystem or its own format?
>
> "This caused write fails for sda1, sdb1 disks along with nvme disks and also
> logged Linux errors."
>
> Do you mean write errors as reported by HTX?

HTX is a user space test-suite using OS system calls to perform write/read
operations to disks. It opens disks using O_DIRECT flag, thus bypasses filesystem
cache with write/read ops. Here HTX has reported write fails with errno = 1
(Operation not permitted) at same time as os-prober fails get logged into
Linux logs. So wondering if its os-prober that somehow caused HTX write
operations to fail ?

And in case yes, wondering if there a way we can prevent write fails
for user space application due to conflict with os-prober ?

>
> The os-prober errors listed are just cosmetic, caused by the fact that
> os-prober, when run (this is run by grub/update-grub to detect possible
> other OSes on the system), will "probe" the filesystems: first detecting the
> available partitions, then attempting to "mount" them to finish probing.
> This is normally done by "grub-probe" and "grub-mount", which should be
> relatively safe, but also *had* another code path to use straight "mount"
> which has shown issues (a fix is available in xenial-proposed for it, should
> be made available in updates soon).
>
> What version of os-prober do you have installed on this system? (use dpkg -l
> os-prober)
>
> If all else fails, we could disable os-prober altogether; there's another
> fix coming up that does so on PowerNV due to the effect on Petitboot.

It will be good to avoid os-prober errors getting logged into Linux.
This will avoid confusion about things going wrong with file systems
onto box, which isn't the reality due to cosmetic errors.