lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sat, 16 Jun 2007 00:40:17 -0400
From:	"Dan Merillat" <dan.merillat@...il.com>
To:	"Neil Brown" <neilb@...e.de>
Cc:	"Wakko Warner" <wakko@...mx.eu.org>, david@...g.hm,
	linux-kernel@...r.kernel.org, linux-raid@...r.kernel.org
Subject: Re: limits on raid

> For raid5 on an array with more than 3 drive, if you attempt to write
> a single block, it will:
>
>  - read the current value of the block, and the parity block.
>  - "subtract" the old value of the block from the parity, and "add"
>    the new value.
>  - write out the new data and the new parity.
>
> If the parity was wrong before, it will still be wrong.  If you then
> lose a drive, you lose your data.

Wow, that really needs to be put somewhere in 120 point red blinking
text.  A lot of us are used to uninitialized disks calculating the
parity-on-first-write, but if linux MD is forgoeing that
'dangerous-no-resync' sounds really REALLY bad.  How about at least a
'Warning: unlike other systems this WILL cause corruption if you
forego reconstruction' on mkraid?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists