From: Francesco Turco <fturco@fastmail.fm>
To: Chris Murphy <lists@colorremedies.com>
Cc: Btrfs BTRFS <linux-btrfs@vger.kernel.org>
Subject: Re: Frequent btrfs corruption on a USB flash drive
Date: Fri, 8 Jul 2016 18:10:46 +0200 [thread overview]
Message-ID: <c8c5564e-623a-f1ca-b1c2-521e18de714c@fastmail.fm> (raw)
In-Reply-To: <CAJCQCtRV2Eis8h9u_Mpum_pFoLzOQe+LjooO0Y4_AYqwsVBiMA@mail.gmail.com>
On 2016-07-07 19:57, Chris Murphy wrote:
> Use F3 to test flash:
> http://oss.digirati.com.br/f3/
I tested my USB flash drive with F3 as you suggested, and there's no
indication it is a fake device.
---------------
# f3probe --destructive /dev/sdb
F3 probe 6.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.
WARNING: Probing normally takes from a few seconds to 15 minutes, but
it can take longer. Please be patient.
Good news: The device `/dev/sdb' is the real thing
Device geometry:
*Usable* size: 57.69 GB (120979456 blocks)
Announced size: 57.69 GB (120979456 blocks)
Module: 64.00 GB (2^36 Bytes)
Approximate cache size: 0.00 Byte (0 blocks), need-reset=no
Physical block size: 512.00 Byte (2^9 Bytes)
Probe time: 2'23"
--------------
$ f3read /run/media/fturco/a7d8a7b1-e0c2-4fbb-879f-e17046989f3c
SECTORS ok/corrupted/changed/overwritten
Validating file 1.h2w ... 2097152/ 0/ 0/ 0
Validating file 2.h2w ... 2097152/ 0/ 0/ 0
Validating file 3.h2w ... 2097152/ 0/ 0/ 0
Validating file 4.h2w ... 2097152/ 0/ 0/ 0
Validating file 5.h2w ... 2097152/ 0/ 0/ 0
Validating file 6.h2w ... 2097152/ 0/ 0/ 0
Validating file 7.h2w ... 2097152/ 0/ 0/ 0
Validating file 8.h2w ... 2097152/ 0/ 0/ 0
Validating file 9.h2w ... 2097152/ 0/ 0/ 0
Validating file 10.h2w ... 2097152/ 0/ 0/ 0
Validating file 11.h2w ... 2097152/ 0/ 0/ 0
Validating file 12.h2w ... 2097152/ 0/ 0/ 0
Validating file 13.h2w ... 2097152/ 0/ 0/ 0
Validating file 14.h2w ... 2097152/ 0/ 0/ 0
Validating file 15.h2w ... 2097152/ 0/ 0/ 0
Validating file 16.h2w ... 2097152/ 0/ 0/ 0
Validating file 17.h2w ... 2097152/ 0/ 0/ 0
Validating file 18.h2w ... 2097152/ 0/ 0/ 0
Validating file 19.h2w ... 2097152/ 0/ 0/ 0
Validating file 20.h2w ... 2097152/ 0/ 0/ 0
Validating file 21.h2w ... 2097152/ 0/ 0/ 0
Validating file 22.h2w ... 2097152/ 0/ 0/ 0
Validating file 23.h2w ... 2097152/ 0/ 0/ 0
Validating file 24.h2w ... 2097152/ 0/ 0/ 0
Validating file 25.h2w ... 2097152/ 0/ 0/ 0
Validating file 26.h2w ... 2097152/ 0/ 0/ 0
Validating file 27.h2w ... 2097152/ 0/ 0/ 0
Validating file 28.h2w ... 2097152/ 0/ 0/ 0
Validating file 29.h2w ... 2097152/ 0/ 0/ 0
Validating file 30.h2w ... 2097152/ 0/ 0/ 0
Validating file 31.h2w ... 2097152/ 0/ 0/ 0
Validating file 32.h2w ... 2097152/ 0/ 0/ 0
Validating file 33.h2w ... 2097152/ 0/ 0/ 0
Validating file 34.h2w ... 2097152/ 0/ 0/ 0
Validating file 35.h2w ... 2097152/ 0/ 0/ 0
Validating file 36.h2w ... 2097152/ 0/ 0/ 0
Validating file 37.h2w ... 2097152/ 0/ 0/ 0
Validating file 38.h2w ... 2097152/ 0/ 0/ 0
Validating file 39.h2w ... 2097152/ 0/ 0/ 0
Validating file 40.h2w ... 2097152/ 0/ 0/ 0
Validating file 41.h2w ... 2097152/ 0/ 0/ 0
Validating file 42.h2w ... 2097152/ 0/ 0/ 0
Validating file 43.h2w ... 2097152/ 0/ 0/ 0
Validating file 44.h2w ... 2097152/ 0/ 0/ 0
Validating file 45.h2w ... 2097152/ 0/ 0/ 0
Validating file 46.h2w ... 2097152/ 0/ 0/ 0
Validating file 47.h2w ... 2097152/ 0/ 0/ 0
Validating file 48.h2w ... 2097152/ 0/ 0/ 0
Validating file 49.h2w ... 2097152/ 0/ 0/ 0
Validating file 50.h2w ... 2097152/ 0/ 0/ 0
Validating file 51.h2w ... 2097152/ 0/ 0/ 0
Validating file 52.h2w ... 2097152/ 0/ 0/ 0
Validating file 53.h2w ... 2097152/ 0/ 0/ 0
Validating file 54.h2w ... 2097152/ 0/ 0/ 0
Validating file 55.h2w ... 2097152/ 0/ 0/ 0
Validating file 56.h2w ... 1364266/ 0/ 0/ 0
Data OK: 55.65 GB (116707626 sectors)
Data LOST: 0.00 Byte (0 sectors)
Corrupted: 0.00 Byte (0 sectors)
Slightly changed: 0.00 Byte (0 sectors)
Overwritten: 0.00 Byte (0 sectors)
Average reading speed: 34.73 MB/s
----------------
> Read more, and also includes a much faster alternative for GNOME:
> https://blogs.gnome.org/hughsie/2015/01/28/detecting-fake-flash/
I also tested my flash drive with gnome-multi-writer-probe, and it says
it is not fake:
# gnome-multi-writer-probe /dev/sdb
Device is GOOD
I also created a big file with dd using /dev/urandom with the same size
as my flash drive, copied it once and read it three times. The SHA-1
checksum is always the same and matches the original one on the hard disk.
So after much testing I feel I can conclude that my USB flash drive is
not fake and it is not defective.
--
Website: http://www.fturco.net/
GPG key: 6712 2364 B2FE 30E1 4791 EB82 7BB1 1F53 29DE CD34
next prev parent reply other threads:[~2016-07-08 16:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-07 13:49 Frequent btrfs corruption on a USB flash drive Francesco Turco
2016-07-07 14:27 ` Austin S. Hemmelgarn
2016-07-07 14:55 ` Francesco Turco
2016-07-07 15:42 ` Austin S. Hemmelgarn
2016-07-07 18:25 ` Chris Murphy
2016-07-07 18:41 ` Francesco Turco
2016-07-07 17:57 ` Chris Murphy
2016-07-08 16:10 ` Francesco Turco [this message]
2016-07-08 16:53 ` Austin S. Hemmelgarn
2016-07-08 18:16 ` Henk Slager
2016-07-07 21:11 ` Andrew E. Mileski
2016-07-07 21:13 ` Francesco Turco
2016-07-07 22:38 ` Andrew E. Mileski
2016-07-07 23:07 ` Chris Murphy
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