Re: [Xen-devel] virtual disk/block-device problem

[Steven Hand <Steven.Hand@xxxxxxxxxxxx>]

>I read in the mailing list archive that this refresh is needed...
>Now I run "fdisk -l" on each of them and get:
>
>       Disk /dev/xvda: 255 heads, 63 sectors, 16 cylinders
>       Disk /dev/xvdb: 255 heads, 63 sectors, 32 cylinders
>       Disk /dev/xvdc: 255 heads, 63 sectors, 48 cylinders
>
>Note the ever increasing number of cylinders.  This makes mkfs think that
>xvdb and xvdc are larger than they really are.  mkfs does succeed, but you
>get a lot of:
>
>       DOM0: Bad return from blkdev data request: 1
>
>on the console.  And if you try to fsck it or actually use it, you get
>filesystem errors.  If I explicitly tell mkfs how big the partition is,
>everything works fine.  So someone is just reporting the geometry wrong,
>probably forgetting to subtract off a non-zero starting location.

Hmm -- the 'geometry' is [supposed to be] hardwired in 1.1 -- see the 
ioctl code in xenolinux-2.4.23-sparse/arch/drivers/block/xl_block.c
Can you "strace fdisk -l" to see how fdisk is computing the values? 

As Ian mentioned previously, this code has all been rewritten for 1.2; 
might be worth giving that a try (although of course 1.2. is still 
awaiting the high-level VD tools...) 

S.