Thanks Rui. That is probably the closest I'll get to confirm my thoughts. I always use sectors. It would seem from this blog that maybe the people who wrote the document at my company simply weren't aware that fdisk can be switched to sectors. >>Do not trust cylinder numbers reported by Linux **fdisk or parted**, because >>both may be rounded to the nearest cylinder. As described in the Linux >>specific section below, set units to sectors in both tools to verify >>alignment. I also check afterwards to ensure they are all correct: fdisk -u -l /dev/mapper/ORA* | grep "/dev/mapper/ORA*" | grep -v "^Disk " -----Original Message----- From: Amaral, Rui [mailto:Rui.Amaral@xxxxxxxxxxxxxxxx] Sent: Thursday, February 07, 2013 7:51 AM To: Walker, Jed S; oracle-l@xxxxxxxxxxxxx Subject: RE: fdisk versus parted Look in the caveats section: https://blogs.oracle.com/dlutz/entry/partition_alignment_guidelines_for_unified Rui Amaral Senior Oracle DBA Oracle Database Engineering, TDBFG -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Walker, Jed S Sent: Thursday, February 07, 2013 9:33 AM To: oracle-l@xxxxxxxxxxxxx Subject: fdisk versus parted We have a company document that says to not use fdisk to partition disks for Oracle. It says to use parted or sfdisk. It says you can't guarantee alignment with fdisk. My best guess is they didn't know about changing fdisk to sector mode, or maybe the risk that you miss it on one, but we are not sure. While building a new system I partitioned one LUN with fdisk and one with parted (just for testing). Using fdisk they both show the same partition, except for parted ended the partition earlier than fdisk, but if I'm looking correctly not at an amount that would somehow make a difference. I also checked the previous RAC I built with fdisk and saw the same result for all those partitions as this fdisked one. If anyone has any insight on this I'd appreciate it. Here is what fdisk shows on the partitions. ORADATA01 was fdisk, ORADATA02 was parted. Note the "End" sector. If I'm missing something obvious please let me know. [root@kdb-ch2-a1p ~]# fdisk /dev/mapper/ORADATA01 WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u'). Command (m for help): u Changing display/entry units to sectors Command (m for help): p Disk /dev/mapper/ORADATA01: 107.4 GB, 107374510080 bytes 255 heads, 63 sectors/track, 13054 cylinders, total 209715840 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x215a6aaa Device Boot Start End Blocks Id System /dev/mapper/ORADATA01p1 2048 209715839 104856896 83 Linux Command (m for help): q [root@kdb-ch2-a1p ~]# fdisk /dev/mapper/ORADATA02 WARNING: DOS-compatible mode is deprecated. It's strongly recommended to switch off the mode (command 'c') and change display units to sectors (command 'u'). Command (m for help): u Changing display/entry units to sectors Command (m for help): p Disk /dev/mapper/ORADATA02: 107.4 GB, 107374510080 bytes 255 heads, 63 sectors/track, 13054 cylinders, total 209715840 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00007076 Device Boot Start End Blocks Id System /dev/mapper/ORADATA02p1 2048 209713151 104855552 83 Linux Command (m for help): q - Jed -- //www.freelists.org/webpage/oracle-l NOTICE: Confidential message which may be privileged. Unauthorized use/disclosure prohibited. If received in error, please go to www.td.com/legal for instructions. AVIS : Message confidentiel dont le contenu peut être privilégié. Utilisation/divulgation interdites sans permission. Si reçu par erreur, prière d'aller au www.td.com/francais/avis_juridique pour des instructions. -- //www.freelists.org/webpage/oracle-l