Hi,
I was directed here by the page at https://www.gnu.org/software/parted/bugs.shtml ; is there any bugreport tracker where one can file a bug instead ? Anyway, here's the problem ( manifested in parted 3.2 coming with Ubuntu 18.04 and checked vs. a manual build of the sources from http://ftp.gnu.org/gnu/parted/parted-3.2.tar.xz ): === parted version === # parted --version parted (GNU parted) 3.2 Copyright (C) 2014 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by <http://git.debian.org/?p=parted/parted.git;a=blob_plain;f=AUTHORS>. === print unit s print unit chs print === # parted /dev/sdi print unit s print unit chs print Model: WDC WD30 EZRZ-00Z5HB0 (scsi) Disk /dev/sdi: 3001GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags Model: WDC WD30 EZRZ-00Z5HB0 (scsi) Disk /dev/sdi: 5860533168s Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags Model: WDC WD30 EZRZ-00Z5HB0 (scsi) Disk /dev/sdi: 364801,80,62 Sector size (logical/physical): 512B/512B BIOS cylinder,head,sector geometry: 364801,255,63. Each cylinder is 8225kB. Partition Table: gpt Disk Flags: Number Start End File system Name Flags === the problem === # parted /dev/sdi GNU Parted 3.2 Using /dev/sdi Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) mkpart test1 0% 1T (parted) unit B (parted) print Model: WDC WD30 EZRZ-00Z5HB0 (scsi) Disk /dev/sdi: 3000592982016B Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 33553920B 1000007477759B 999973923840B test1 (parted) align-check optimal 1 1 aligned (parted) align-check minimal 1 1 not aligned (parted) ===== First of all, start sector value looks insanely big for "0%" ; second, one would imagine that passing an optimal check would imply passing a minimal check. If one tries to start at e.g. 1 MiB, then of course the optimal check will not pass : ===== # parted /dev/sdi GNU Parted 3.2 Using /dev/sdi Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print Model: WDC WD30 EZRZ-00Z5HB0 (scsi) Disk /dev/sdi: 3001GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags (parted) mkpart test1 ext2 2048s 1T Warning: The resulting partition is not properly aligned for best performance. Ignore/Cancel? I (parted) unit B (parted) print Model: WDC WD30 EZRZ-00Z5HB0 (scsi) Disk /dev/sdi: 3000592982016B Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 1048576B 1000000000511B 999998951936B ext2 test1 (parted) align-check optimal 1 1 not aligned (parted) align-check minimal 1 1 aligned ===== As it turns out, the root of all evil comes from here : ===== # cat /sys/block/sdi/queue/optimal_io_size 33553920 ===== So parted is not to blame, but the system. But from the user's point of view, it is quite hard to figure this out. And certainly the user deserves to know the actual values that parted considers to be of best performance -- I mean, pa->offset and pa->grain_size from parted.c::print_partition_alignment() shall probably be exposed in some way -- at least when it comes to a warning like the one above. Kind regards Georgy Fedorov Senior Systems Specialist Melbourne School of Engineering The University of Melbourne, Victoria 3010, Australia email: gfedo...@unimelb.edu.au<mailto:gfedo...@unimelb.edu.au> http://www.eng.unimelb.edu.au <https://owa.unimelb.edu.au/owa/redir.aspx?SURL=zZ66u8zSk7WjNEV9pSzLYdWdXh0cvHwxj-uz4bP1rcBS-JFIAfjRCGgAdAB0AHAAOgAvAC8AdwB3AHcALgBlAG4AZwAuAHUAbgBpAG0AZQBsAGIALgBlAGQAdQAuAGEAdQAvAA..&URL=http%3a%2f%2fwww.eng.unimelb.edu.au%2f>
