From: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
To: "David C. Rankin" <drankinatty@suddenlinkmail.com>
Cc: Linux Raid <linux-raid@vger.kernel.org>
Subject: Re: Feature request: Remove the badblocks list
Date: Wed, 2 Sep 2020 15:36:09 +0200 (CEST) [thread overview]
Message-ID: <51057261.933837.1599053769942.JavaMail.zimbra@karlsbakk.net> (raw)
In-Reply-To: <37b43194-f372-dd04-a319-34406f63c5a2@suddenlinkmail.com>
----- Original Message -----
> From: "David C. Rankin" <drankinatty@suddenlinkmail.com>
> To: "Linux Raid" <linux-raid@vger.kernel.org>
> Sent: Saturday, 22 August, 2020 03:42:40
> Subject: Re: Feature request: Remove the badblocks list
> On 8/18/20 4:03 PM, Håkon Struijk Holmen wrote:
>> Hi,
>>
>> Thanks for the CC, I just managed to get myself subscribed to the list :)
>>
>> I have gathered some thoughts on the subject as well after reading up on it,
>> figuring out the actual header format is, and writing a tool [3] to fix my
>> array...
>>
> <snip>
>> But I have some complaints about the thing..
>
> Well,
>
> There is code in all things that can be fixed, but I for one will chime in
> and say I don't care if a lose a strip or two so long as on a failed disk I
> pop the new one in and it rebuilds without issue (which it does, even when the
> disk was replaced due to bad blocks)
>
> So whatever is done, don't fix what isn't broken and introduce more bugs
> along the way. If this is such an immediate problem, then why are patches
> being attached to the complaints?
The problem is that it's already broken. Take a single mirror. One drive experiences a bad sector, fine, you have redundancy, so you read the data from the other drive and md flags the sector as bad. The drive two is replaced, you lose the data. The new drive will get flagged with the same sector number as faulty, since the first drive has it flagged. So you replace the first drive and during resync, it also gets flagged as having a bad sector. And so on.
Modern (that is, disks since 20 years ago or so) reallocate sectors as they wear out. We have redundancy to handle errors, not to pinpoint them on disks and fill up not-so-smart lists with broken sectors that work. If md sees a drive with excessive errors, that drive should be kicked out, marked as dead, but not interfere with the rest of the raid.
Vennlig hilsen
roy
--
Roy Sigurd Karlsbakk
(+47) 98013356
http://blogg.karlsbakk.net/
GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
--
Hið góða skaltu í stein höggva, hið illa í snjó rita.
next prev parent reply other threads:[~2020-09-02 13:47 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-18 18:00 Feature request: Remove the badblocks list Roy Sigurd Karlsbakk
2020-08-18 19:26 ` Wols Lists
2020-08-18 19:34 ` Piergiorgio Sartor
2020-08-18 19:43 ` Phil Turmel
2020-08-18 21:03 ` Håkon Struijk Holmen
2020-08-22 1:42 ` David C. Rankin
2020-09-02 13:36 ` Roy Sigurd Karlsbakk [this message]
2020-09-02 14:34 ` Adam Goryachev
2020-09-02 14:50 ` Roy Sigurd Karlsbakk
2020-09-02 15:09 ` Adam Goryachev
2020-09-02 15:25 ` Roy Sigurd Karlsbakk
2020-09-02 16:32 ` Adam Goryachev
2020-09-02 16:50 ` Roy Sigurd Karlsbakk
2020-09-02 19:45 ` Håkon Struijk Holmen
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=51057261.933837.1599053769942.JavaMail.zimbra@karlsbakk.net \
--to=roy@karlsbakk.net \
--cc=drankinatty@suddenlinkmail.com \
--cc=linux-raid@vger.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