Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
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.
Copy & past from upstream:
# modprobe scsi_debug dev_size_mb=1024 sector_size=4096
# fdisk /dev/sdb
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4, default 1):
Using default value 1
First sector (256-262143, default 256): 257
Last sector, +sectors or +size{K,M,G} (257-262143, default 262143): +100M
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes
32 heads, 32 sectors/track, 256 cylinders, total 262144 sectors
Units = sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 262144 bytes
Disk identifier: 0x16db2bb0
Device Boot Start End Blocks Id System
/dev/sdb1 257 25855 102396 83 Linux
Partition 1 does not start on physical sector boundary.
^^^^^^^^
The warning is nonsense. The logical and physical sector size is the
same. It means that every LBA is always aligned to physical sector
boundary.
Note that this bug does not mean that fdisk produces unaligned
partitions. The problem is that fdisk forces to use bigger gaps
between aligned LBAs, for example:
correctly aligned LBA are: 256, 257, 258, ... [N+1]
fdisk assumes: 256, 264, 272, ... [N+(sector_size/512)]
Bug fix is pretty simple:
- unsigned long long offset = (lba << 9) & (granularity - 1);
+ unsigned long long offset = (lba * sector_size) & (granularity - 1);
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.
http://rhn.redhat.com/errata/RHBA-2011-0699.html
Copy & past from upstream: # modprobe scsi_debug dev_size_mb=1024 sector_size=4096 # fdisk /dev/sdb Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4, default 1): Using default value 1 First sector (256-262143, default 256): 257 Last sector, +sectors or +size{K,M,G} (257-262143, default 262143): +100M Command (m for help): p Disk /dev/sdb: 1073 MB, 1073741824 bytes 32 heads, 32 sectors/track, 256 cylinders, total 262144 sectors Units = sectors of 1 * 4096 = 4096 bytes Sector size (logical/physical): 4096 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 262144 bytes Disk identifier: 0x16db2bb0 Device Boot Start End Blocks Id System /dev/sdb1 257 25855 102396 83 Linux Partition 1 does not start on physical sector boundary. ^^^^^^^^ The warning is nonsense. The logical and physical sector size is the same. It means that every LBA is always aligned to physical sector boundary. Note that this bug does not mean that fdisk produces unaligned partitions. The problem is that fdisk forces to use bigger gaps between aligned LBAs, for example: correctly aligned LBA are: 256, 257, 258, ... [N+1] fdisk assumes: 256, 264, 272, ... [N+(sector_size/512)] Bug fix is pretty simple: - unsigned long long offset = (lba << 9) & (granularity - 1); + unsigned long long offset = (lba * sector_size) & (granularity - 1);