By default fdisk detects dos partitions , you need to change mode to see GPT partitions. I didn't see ceph-disk output below , at what sector it is starting with ? Thanks & Regards Somnath -----Original Message----- From: Василий Ангапов [mailto:angapov@xxxxxxxxx] Sent: Monday, February 22, 2016 11:09 PM To: Loic Dachary Cc: Somnath Roy; ceph-devel Subject: Re: ceph-disk disk partition alignment In my case (Hammer 0.94.5) I see actually the proper alignment made by ceph-disk. Thing is that fdisk is not able to see GPT partitions: root@slpeah001:[~]:# fdisk -l /dev/sdf Disk /dev/sdf: 4000.8 GB, 4000787030016 bytes, 7814037168 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 label type: dos Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdf1 1 4294967295 2147483647+ ee GPT root@slpeah001:[~]:# gdisk -l /dev/sdf GPT fdisk (gdisk) version 0.8.6 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Disk /dev/sdf: 7814037168 sectors, 3.6 TiB Logical sector size: 512 bytes Disk identifier (GUID): E1063D97-3EFF-4F81-A08F-81D069625677 Partition table holds up to 128 entries First usable sector is 34, last usable sector is 7814037134 Partitions will be aligned on 2048-sector boundaries Total free space is 2014 sectors (1007.0 KiB) Number Start (sector) End (sector) Size Code Name 1 2048 7814037134 3.6 TiB FFFF ceph data So I think ceph-disk does things right... But before I use ceph-disk I create an empty GPT with gdisk. 2016-02-23 13:49 GMT+08:00 Loic Dachary <loic@xxxxxxxxxxx>: > Here it is http://tracker.ceph.com/issues/14842 > > On 23/02/2016 12:24, Somnath Roy wrote: >> eph-deploy is creating data partition from sector 1 ignoring what sgdisk is recommending (256 in my disk). Basically, it should be aligned with physical sector size (reported in /sys/block/<device>/queue/physical_block_size). In my case it is 16K physical and 4K logical...256 is perfectly fine as sgdisk/fdisk internally decides. >>> Disk performance will be severely impacted because of partitioning >>> this way from ceph-deploy , > > -- > Loïc Dachary, Artisan Logiciel Libre > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" > in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo > info at http://vger.kernel.org/majordomo-info.html PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies). ��.n��������+%������w��{.n����z��u���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
