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]
Message-id: <4FAC9EC4.1000906@shiftmail.org>
Date:	Fri, 11 May 2012 07:08:20 +0200
From:	Asdo <asdo@...ftmail.org>
To:	Jan Kara <jack@...e.cz>
Cc:	linux-ext4@...r.kernel.org
Subject: Re: ext4 barrier on SCSI vs SATA?

On 05/09/12 21:50, Jan Kara wrote:
> []

I have some troubles understanding the barriers thing, can you help me?


In the past some blockdevices would not provide / propagate the 
barriers, e.g. MD raid 5 would not.  So filesystems during mount would 
try the barrier operation and see that it wouldn't work, so they would 
disable barrier option and mount as nobarrier.

However the flush was always available (I think), in fact databases 
would not corrupt (not even above ext4 nobarrier, above a raid5 without 
barriers) if fsync was called at proper times.

So first question is : why filesystems were not using the flush as a 
barrier like databases did?

Second question is : was a nobarrier mount (ext4) more risky in terms of 
data or metadata lost on sudden power loss?

Thank you
Asdo
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ