DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 2E0C43858D35
Subject: Re: [cygwin] DD bug fails to wipe last 48 sectors of a disk
To: cygwin@cygwin.com
References: <DB7PR01MB5193A18F1D947ED4C276CD25D5980@DB7PR01MB5193.eurprd01.prod.exchangelabs.com>
 <1d1801d64677$bea56050$3bf020f0$@pdinc.us>
 <DB7PR01MB5193CC1C7630FB13B81B9DBAD5980@DB7PR01MB5193.eurprd01.prod.exchangelabs.com>
 <60bf1507-4edb-a03f-ec14-07e1ab7f0d94@cs.umass.edu>
 <DB7PR01MB519396195ADB3E3E1217B22BD5940@DB7PR01MB5193.eurprd01.prod.exchangelabs.com>
 <CAKNeuBqZpacuUwTD6U+kKPGOO052VYhpRnttm=HYr7m+OT7tiA@mail.gmail.com>
 <DB7PR01MB519371C6CAE2D3CFFEF41DCAD5940@DB7PR01MB5193.eurprd01.prod.exchangelabs.com>
 <1814912576.20200624132126@yandex.ru>
 <DB7PR01MB5193DE112A6F56F04CB40B8BD5950@DB7PR01MB5193.eurprd01.prod.exchangelabs.com>
From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
Autocrypt: addr=Brian.Inglis@SystematicSw.ab.ca; prefer-encrypt=mutual;
 keydata=
 mDMEXopx8xYJKwYBBAHaRw8BAQdAnCK0qv/xwUCCZQoA9BHRYpstERrspfT0NkUWQVuoePa0
 LkJyaWFuIEluZ2xpcyA8QnJpYW4uSW5nbGlzQFN5c3RlbWF0aWNTdy5hYi5jYT6IlgQTFggA
 PhYhBMM5/lbU970GBS2bZB62lxu92I8YBQJeinHzAhsDBQkJZgGABQsJCAcCBhUKCQgLAgQW
 AgMBAh4BAheAAAoJEB62lxu92I8Y0ioBAI8xrggNxziAVmr+Xm6nnyjoujMqWcq3oEhlYGAO
 WacZAQDFtdDx2koSVSoOmfaOyRTbIWSf9/Cjai29060fsmdsDLg4BF6KcfMSCisGAQQBl1UB
 BQEBB0Awv8kHI2PaEgViDqzbnoe8B9KMHoBZLS92HdC7ZPh8HQMBCAeIfgQYFggAJhYhBMM5
 /lbU970GBS2bZB62lxu92I8YBQJeinHzAhsMBQkJZgGAAAoJEB62lxu92I8YZwUBAJw/74rF
 IyaSsGI7ewCdCy88Lce/kdwX7zGwid+f8NZ3AQC/ezTFFi5obXnyMxZJN464nPXiggtT9gN5
 RSyTY8X+AQ==
Organization: Systematic Software
Message-ID: <96fa977c-2b02-329f-3ab5-f7eedc28d556@SystematicSw.ab.ca>
Date: Thu, 25 Jun 2020 07:25:47 -0600
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101
 Thunderbird/68.9.0
MIME-Version: 1.0
In-Reply-To: <DB7PR01MB5193DE112A6F56F04CB40B8BD5950@DB7PR01MB5193.eurprd01.prod.exchangelabs.com>
Content-Language: en-CA
Precedence: list
Reply-To: cygwin@cygwin.com
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Errors-To: cygwin-bounces@cygwin.com
Sender: "Cygwin" <cygwin-bounces@cygwin.com>

On 2020-06-25 06:08, Hashim Aziz via Cygwin wrote:
> On 24 June 2020 11:21 AM, Andrey Repin wrote:
>> Bottom posting in this channel, please.
>> 
>>> I've just tested with the command:
>> 
>>> dd if=/dev/zero of=/dev/sda iflag=fullblock bs=4M status=progress
>> 
>> oflag=direct
>> 
>> Although I'm unsure how Cygwin/Windows handles it. But without this flag, the
>> write is cached, and the problem may be outside dd, or even Cygwin.
>> 
>>> ...and can confirm that the last 48 sectors remain unwiped in this case also.
>> 
>>> Here is the output:
>> 
>>> 1000182120448 bytes (1.0 TB, 931 GiB) copied, 8284 s, 121 MB/s
>>> dd: error writing '/dev/sda': No space left on device
>>> 238468+0 records in
>>> 238467+0 records out
>>> 1000204861440 bytes (1.0 TB, 932 GiB) copied, 8284.89 s, 121 MB/s

> I have no idea what bottom posting is, mailing lists are new to me and I find
> them a very archaic and noisy way to communicate development changes. I 
> really wish the Cygwin dev team would enter the 21st century and move to a 
> modern development process involving a repository like Github, I'm convinced 
> it would increase developer engagement with the project massively while 
> cutting down on so much of the noise.
> I ran:> dd if=/dev/zero of=/dev/SDA bs=4m oflag=direct status=progress
> ...and can confirm the bug still presents - the last 48 sectors fail to be
> wiped.
Please learn to use web search and/or information sites to educate yourself on
topics new to you:

	https://en.wikipedia.org/wiki/Web_search_query
	https://en.wikipedia.org/wiki/Mailing_list
	https://en.wikipedia.org/wiki/Posting_style

and please trim others' email addresses so you do not quote them verbatim in
public posts which may be harvested by spammers.

The Cygwin project is all volunteer with zero budget and little free time, on
free shared infrastructure provided for more mainline projects.

Fixing code, updating packages, and responding to posts are the priorities, in
that order, if people have any free time to spare.

When days, weeks, or months may pass between checking, active mailing lists can
be more effectively filtered, to see what posts may be relevant for maintainers
to look at.

Other users with more experience and free time may try to help posters with
information or suggestions as first or second level type support, until
maintainers have time to look and perhaps respond.

Please also remember that presently maintainers may be dealing with other issues
and priorities e.g. health, home, family, work, and may have no free time for
weeks to come.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in IEC units and prefixes, physical quantities in SI.]
--
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple