Red Hat Bugzilla – Bug 474902
[LTC 5.4 FEAT] 4K Byte Sector HDDs Support (data disk) 
Last modified: 2011-12-02 14:08:53 EST
Emily J. Ratliff <firstname.lastname@example.org> -
1. Feature Overview:
Feature Id: 
a. Name of Feature: 4K Byte Sector HDDs Support
b. Feature Description
The SCSI core disk driver appears to already have support for multiple sector sizes. Tools,
filesystem and other driver updates may be required to ensure the 4K sector size HDDs function and
perform correctly. Will need to confirm when 4k sector HDDs are available for testing. Adding a new
4K drive to a system will be the same as adding a 512 byte sector drive.
2. Feature Details:
Arch Specificity: Purely Common Code
Affects Kernel Modules: Yes
Request Type: Kernel - Enhancement from Upstream
d. Upstream Acceptance: Accepted
Sponsor Priority 2
f. Severity: Medium
IBM Confidential: no
Code Contribution: unsure
g. Component Version Target: Per code review, support for multiple sector sizes appears to be
available in 2.6.24. Will require validation.
3. Business Case
Drives with 4 kilobyte physical sectors will be making their way to the marketplace and the
expectation from customers will be the same as for 512 byte sectors.
4. Primary contact at Red Hat:
5. Primary contacts at Partner:
Project Management Contact:
Monte Knutson, email@example.com, 877-894-1495
Kevin Stansell, firstname.lastname@example.org
Chris McDermott, email@example.com
Julio Alvarez, firstname.lastname@example.org
IBM is signed up to test and provide feedback.
Updating PM score.
Note that we have uncovered multiple issues with our SAS testing - everything from lack of BIOS support for booting from the 4KB drive up to various boot utilities.
It would be great to get a board with BIOS support for this during our debug.
The last comment brings up a good point. Support for this is likely to be feasible first for non-boot, data disks. Boot support is likely to follow, because of BIOS issues, at a minimum.
I will leave this BZ for the data disk part of the problem. This will remain targeted at 5.4, although at this point, it looks like it will be a tech. preview at best. I will clone another BZ, to focus on boot support. This will be targeted at 5.5. I imagine the same scenario will apply to RHEL 6.0 and 6.1 as well (Bug 463632).
Partial fixes for this are on upstream parted's next branch.
Just today I've begun testing with real 4KB-sector hardware, and have found a new bug in that code (not surprising, since it wasn't close to completion). Currently I plan to concentrate on getting robust support for gpt and msdos partition table formats. dvh might be next, but if people have other favorites, please list them here.
The deadline for kernel code submissions is quickly approaching. Are the kernel portions of this BZ on track for the 4/23 kernel freeze? If you need help with testing, access to hardware, etc., just let me know. Thanks!
Closing as WONTFIX for RHEL 5.4 due to lack of capacity, please feel free to
reopen to request this feature for consideration for RHEL 5.5
------- Comment From 2011-02-22 04:28 EDT-------
We are reviewing this as a part of backlog bug clean up activity.
As per last comment closing this as WILL_NOT_FIX.
Please feel free to reopen once you have any valid update.