Thank you -- that's a very good point.
Just in case if this thread would get indexed, I would add a
reference for usb-storage quirks:
https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html
( search for "usb-storage.quirks=" )
Kind regards, George
On 4/8/19 2:15 am, Volta wrote:
I'm not a parted dev, just a user, but I've run into this same issue
several times. This wouldn't happen to be a USB device using the UAS
driver? IME setting quirks mode for such devices so they use the
usb-storage driver instead yields sensible values for optimal_io_size,
etc. so parted can do the right thing with 0% and properly align the
partitions. This also works around other issues I've had with these
devices randomly disconnecting when using UAS. My
/etc/modprobe.d/usbdisks.conf file contains:
options usb-storage
quirks=0x0bc2:0xab31:u,0x0bc2:0x3322:u,0x0bc2:0xa0a4:u,0x0bc2:0x331a:u,0x0bc2:3343:u
get the device identifiers for the affected device(s) from lsusb,
stick them in there, then 'depmod -a' and reboot or remove and
reattach the device(s) (the latter should work, but sometimes the
kernel doesn't do the right thing, and I've not bothered to
investigate further as I only use USB disks on workstations that are
easily rebooted), then try parted again.
Doesn't really "solve" the problem, which I understand to be with the
UAS implementation in these devices, but at least it is a usable
workaround.
On Sat, 3 Aug 2019 at 11:18, George Fedorov <address@hidden> wrote:
Hi,
I was directed here by the page at https://protect-au.mimecast.com/s/yFf9CWLJMvF3vx10s6x6jT?domain=gnu.org ; 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 https://protect-au.mimecast.com/s/b7SyCXLKNwFA3GlmTVBluL?domain=ftp.gnu.org ):
=== parted version ===
# parted --version
parted (GNU parted) 3.2
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://protect-au.mimecast.com/s/wE-3CYWLOxhYPgK5s9N9ZR?domain=gnu.org>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by <https://protect-au.mimecast.com/s/T3hlCZYMPyCvyx1zcygnbo?domain=git.debian.org>.
=== 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: address@hidden
http://www.eng.unimelb.edu.au
--
George Fedorov
Senior Systems Specialist
Melbourne School of Engineering
The University of Melbourne, Victoria 3010, Australia
email: address@hidden
http://www.eng.unimelb.edu.au/
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