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 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
