[Parted-maintainers] Bug#778712: libparted2: Breakage of RAID GPT header

[jnqnfe]

On Wed, 2015-02-18 at 16:35 -0500, Phillip Susi wrote:
> On 2/18/2015 4:05 PM, jnqnfe wrote:
> > Background ================= I have a 'fake-raid' RAID0 array,
> > created from two HDDs using my motherboard firmware. This is not
> > used for root, just data.
> 
> FYI, unless you have to dual boot with windows, you should avoid using
> fakeraid and stick with conventional linux software raid, which is
> much better supported.

Fine, fair enough, I am not dual booting so I may switch as you suggest.
Thanks for the tip.

> > sdb and sdc are the RAID members here and the RAID device is
> > md126.
> 
> Then you need to only manipulate md126 and ignore sdb and sdc.  Most
> of what you seem to be reporting involves looking directly at the
> individual disks, which you must not do as that will present a
> partial/corrupt view of the raid array.  In other words, if the first
> few sectors of the raid array map to sdb, then sdb will appear to have
> a partition table in its sector 0 that describes a disk that is twice
> the size, since this partition table is actually describing the raid
> array and not the individual disk.

I am not doing anything at all to the member disks, I am only
manipulating the array (mb126) and providing the ouput of fsdisk -l /
parted -l (with unnecessary info about other disks removed).

> The one thing you mention that I can't write off as user error is "but
> parted is not and seems to be forcibly applying what it believes to be
> correct (ignoring the fact that it was only asked to display info, not
> modify anything)".  Can you provide more details here?  Exactly what
> command did you run and what changed before vs. after?  Parted should
> not be modifying anything on the disk unless you tell it to.  Normally
> it will throw a warning telling you something is wrong with the disk
> and ask if you want it to fix it and you have to answer "fix" for it
> to modify the disk.

I did only exactly as described in my previous message, nothing more,
nothing less.