From: Roman Mamedov <rm@romanrm.net>
To: Andreas Klauer <Andreas.Klauer@metamorpher.de>
Cc: Shaohua Li <shli@kernel.org>,
linux-raid@vger.kernel.org, jes.sorensen@gmail.com,
neilb@suse.de
Subject: Re: RAID creation resync behaviors
Date: Thu, 4 May 2017 13:06:27 +0500 [thread overview]
Message-ID: <20170504130627.4f20f79c@natsu> (raw)
In-Reply-To: <20170504075551.GA3929@metamorpher.de>
On Thu, 4 May 2017 09:55:51 +0200
Andreas Klauer <Andreas.Klauer@metamorpher.de> wrote:
> For example? I was under the impression that pretty much all of them do.
> Even the ones that don't advertize it returned zero after trim for me.
> [Sometimes you get original data but that's Linux; gone after drop_caches]
> (Of course, I don't have access to that many different models of SSD...)
>
> But what do they actually return then? Original data?
Consult Wikipedia at least, if not the original ATA standards documents:
https://en.wikipedia.org/wiki/Trim_(computing)#ATA
Can return "undefined", "something that is the same every time" or "zeroes".
Apparently the OS can query which is to be expected with a particular device,
but firstly, you can't necessarily trust that 100%, and secondly, that's
operating on a level lower (ATA) than where md is.
--
With respect,
Roman
next prev parent reply other threads:[~2017-05-04 8:06 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-03 20:27 RAID creation resync behaviors Shaohua Li
2017-05-03 21:06 ` David Brown
2017-05-04 1:54 ` Shaohua Li
2017-05-04 7:37 ` David Brown
2017-05-04 16:02 ` Wols Lists
2017-05-04 21:57 ` NeilBrown
2017-05-05 6:46 ` David Brown
2017-05-04 15:50 ` Wols Lists
2017-05-04 22:00 ` NeilBrown
2017-05-03 23:58 ` Andreas Klauer
2017-05-04 2:22 ` Shaohua Li
2017-05-04 7:55 ` Andreas Klauer
2017-05-04 8:06 ` Roman Mamedov [this message]
2017-05-04 15:20 ` Brad Campbell
2017-05-04 1:07 ` NeilBrown
2017-05-04 2:04 ` Shaohua Li
2017-05-09 18:39 ` Jes Sorensen
2017-05-09 20:30 ` NeilBrown
2017-05-09 20:49 ` Jes Sorensen
2017-05-09 21:03 ` Martin K. Petersen
2017-05-09 21:11 ` Jes Sorensen
2017-05-09 21:16 ` Martin K. Petersen
2017-05-09 21:22 ` Jes Sorensen
2017-05-09 23:56 ` Martin K. Petersen
2017-05-10 5:58 ` Hannes Reinecke
2017-05-10 22:20 ` Martin K. Petersen
2017-05-10 17:30 ` Shaohua Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170504130627.4f20f79c@natsu \
--to=rm@romanrm.net \
--cc=Andreas.Klauer@metamorpher.de \
--cc=jes.sorensen@gmail.com \
--cc=linux-raid@vger.kernel.org \
--cc=neilb@suse.de \
--cc=shli@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).