Comment 13 for bug 530071

Hi Colin,

Looks good - defaulting to 1MB boundaries seems to be a good safe option for
all concerned. I hope the beta becomes visible soon so I can get a copy!

That USB enclosure only reports SPC-2 and so it would not be expected to get
READ CAPACITY(16) from the host to report sector size/alignment data. In
fact with the current firmware, it will support READ CAPACITY(16) but does
not fill in the sector/alignment bytes.

If we added SPC-3 reporting and fixed the appropriate commands, are you
saying that as a USB device, we will still never get the chance to return
our parameters from READ CAPACITY(16) as the kernel will force the USB
entity to be SPC-2? We are looking at how we can accommodate Advanced Format
drives in USB in the US for our external drives.

Cheers

Steve

Steve Perkins
Field Technical Consultant
Western Digital (UK) Ltd.
Prime House,Challenge Court,
Barnett Wood Lane, Leatherhead
Surrey KT22 7DE
+44 1372 366034
<email address hidden>
Mob: +44 7780 990809

> -----Original Message-----
> From: <email address hidden> [mailto:<email address hidden>] On Behalf Of
> Colin Watson
> Sent: Thursday, March 18, 2010 22:11
> To: Steve Perkins
> Subject: [Bug 530071] Re: Lucid Default live-cd install fails with 4K
> sector /Advanced Format drives
>
> I've tested on the USB-adapted drive you sent me (thanks again!), and
> confirmed that the beta-1 installer defaults to 1MiB boundaries on that
> drive. This should apply to all USB drives, since the Linux kernel
> suppresses the SPC-3 command set unilaterally for USB mass-storage
> devices regardless of what the adapter does.
>
> --
> Lucid Default live-cd install fails with 4K sector / Advanced Format
> drives
> https://bugs.launchpad.net/bugs/530071
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in "e2fsprogs" package in Ubuntu: New
> Status in "partman-base" package in Ubuntu: Fix Released
> Status in "partman-ext3" package in Ubuntu: In Progress
> Status in "ubiquity" package in Ubuntu: Triaged
> Status in "util-linux" package in Ubuntu: New
> Status in "e2fsprogs" source package in Lucid: New
> Status in "partman-base" source package in Lucid: Fix Released
> Status in "partman-ext3" source package in Lucid: In Progress
> Status in "ubiquity" source package in Lucid: Triaged
> Status in "util-linux" source package in Lucid: New
>
> Bug description:
> Binary package hint: ubiquity
>
> Use default partition layout for Lucid Allpha 3 on new hard disk fails to
> account for 4K sector / Advanced Format drives. For example WD10-EARS
> which reports sector alignment in Identify Drive as 4KB internal sectors,
> 512 external.
> Ubiquity hangs during "Partition Formatting" at 5% with "Creating ext4
> file system for / in partition #1 of SCSI1 (0,0,0) (sda)...".
>
> Open terminal and fdisk -l shows partitions are created correctly but
> don't "start on optimal I/O boundary". Shut down ubiquity and attempt a
> manual mkfs.ext4 and I get a warning:
> /dev/sda1 alignment is offset by 512 bytes.
> This may result in very poor performance, (re)-partitioning suggested.
> Proceed anyway? (y,n)
>
> So the tools here (fdisk, mkfs) are correctly picking up that the drive
> has a prefered alignment but Ubiquity installation does not. I presume
> that the warning question from mkfs.ext4 asking for y/n confirmation is
> not catered for in the installation scripts which presumably expect a
> completion on mkfs.ext4.
>
> If a manual partition set is created based on correct alignment and
> mkfs.ext4 run, the ubiquity installation can complete correctly if manual
> use of existing partitions is selected. Fdisk can be used here as long as
> care is taken with the boundaries. The --align options under parted 2.1
> would make this simpler to configure but I think there is already a plan
> to include parted 2.1 in Lucid if possible.
>
> The best solution would entail the installation tools aligning partitons
> to the optimum alignment for the drive which would make sure the best
> performance is obtained in the OS. Failing this, at least the installation
> needs to allow for the mkfs changes (warning message) or the default
> installation can not be used on the new drives.
>
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