RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Bug 621684 - default to aligning the LUKS data areas on a 1MB boundary
Summary: default to aligning the LUKS data areas on a 1MB boundary
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: cryptsetup-luks
Version: 6.0
Hardware: All
OS: Linux
low
medium
Target Milestone: rc
: ---
Assignee: Milan Broz
QA Contact: Release Test Team
URL:
Whiteboard:
Depends On: 621673 623458 623703
Blocks: 569949
TreeView+ depends on / blocked
 
Reported: 2010-08-05 19:49 UTC by Mike Snitzer
Modified: 2013-03-01 04:09 UTC (History)
12 users (show)

Fixed In Version: cryptsetup-luks-1.1.2-2.el6
Doc Type: Bug Fix
Doc Text:
Clone Of: 621673
Environment:
Last Closed: 2010-11-10 20:05:02 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)

Description Mike Snitzer 2010-08-05 19:49:30 UTC 
Following describes speaks about LVM; but the same applies to LUKS.

+++ This bug was initially created as a clone of Bug #621673 +++

Description of problem:
The new standard in the storage industry is to default alignment of data
areas to 1MB.  fdisk, parted, and mdadm have all been updated to this
default.

Update LVM to align the PV's data area start (pe_start) to 1MB.  This
provides a more useful default than the previous default of 64K (which
generally ended up being a 192K pe_start once the first metadata area
was created).

Having recently boasted about the new 1MB default in the RHEL6 storage
stack I was soon faced with the harsh reality that LVM was a weak link
(on legacy hardware that doesn't export I/O topology limits).

This meant that an 8 disk HW raid0 array (with 64K chunk_size) ended up
having a PV pe_start that was not aligned on a full-stripe boundary.  As
such the array was misaligned -- resulting is suboptimal performance. 
The array would've been configured optimally "out of the box" had LVM
used a default alignment of 1MB.

Steps to Reproduce:
1. pvcreate /dev/sdd
2. vgcreate test /dev/sdd
3. pvs -o name,vg_mda_size,pe_start
  
Actual results:
# pvs -o name,vg_mda_size,pe_start                                                                                                                                     
  PV         VMdaSize  1st PE
  /dev/sdd     188.00k 192.00k

Expected results:
# pvs -o name,vg_mda_size,pe_start                                                                                                                                     
  PV         VMdaSize  1st PE
  /dev/sdd    1020.00k   1.00m

--- Additional comment from msnitzer on 2010-08-05 15:27:48 EDT ---

Patch posted to lvm-devel:
http://www.redhat.com/archives/lvm-devel/2010-August/msg00035.html
Comment 3 Milan Broz 2010-08-10 10:47:57 UTC 
Fixed in cryptsetup-luks-1.1.2-2.el6.
Comment 6 Pavel Holica 2010-08-13 12:03:28 UTC 
Verified on RHEL6.0-20100811.2 x86_64 and i386 Server with cryptsetup-luks-1.1.2-2.el6.

Waiting for verification on ppc64 and s390x.
Comment 8 releng-rhel@redhat.com 2010-11-10 20:05:02 UTC 
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.
Note You need to log in before you can comment on or make changes to this bug.