Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 24 Oct 2019 16:34:19 -0400
From:   "Theodore Y. Ts'o" <tytso@mit.edu>
To:     Boaz Harrosh <openosd@gmail.com>
Cc:     Paul Menzel <pmenzel@molgen.mpg.de>, linux-fsdevel@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Donald Buczek <buczek@molgen.mpg.de>
Subject: Re: File system for scratch space (in HPC cluster)
Message-ID: <20191024203419.GG1124@mit.edu>
References: <e143071a-b1dc-56a4-a82e-865bae4c60c1@molgen.mpg.de>
 <20191024145504.GD1124@mit.edu>
 <70755c40-b800-8ba0-a0df-4206f6b8c8d4@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <70755c40-b800-8ba0-a0df-4206f6b8c8d4@gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Oct 24, 2019 at 06:01:05PM +0300, Boaz Harrosh wrote:
> > You could use ext4 in nojournal mode.  If you want to make sure that
> > fsync() doesn't force a cache flush, you can mount with the nobarrier
> > mount option.
> 
> And open the file with O_TMPFILE|O_EXCL so there is no metadata as well.

O_TMPFILE means that there is no directory entry created.  The
pathname passed to the open system call is the directory specifying
the file system where the temporary file will be created.

This may or may not be what the original poster wanted, depending on
whether by "scratch file" he meant a file which could be opened by
pathname by another, subsequent process or not.

    	 	      	  	    	 - Ted