All of lore.kernel.org
 help / color / mirror / Atom feed
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

  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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.