From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: [PATCH] generic/017: skip tests with mkfs failures Date: Tue, 7 Oct 2014 22:11:02 -0400 Message-ID: <20141008021102.GA20071@thunk.org> References: <1412619830-23088-1-git-send-email-paul.paulson@seagate.com> <20141007005300.GA11741@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: fstests@vger.kernel.org, linux-ext4@vger.kernel.org To: Paul Paulson Return-path: Received: from imap.thunk.org ([74.207.234.97]:41644 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266AbaJHCLH (ORCPT ); Tue, 7 Oct 2014 22:11:07 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Oct 07, 2014 at 01:12:51PM -0500, Paul Paulson wrote: > We'd like to run the full test suite using maximum partition sizes on > SMR drives for functional and performance evaluation purposes. Since > drive capacities are increasing so rapidly it would be nice if mke2fs > would support filesystems up to the maximum configurations specified > in the Ext4_Disk_Layout document using default filesystem configs. For > example, the 127877120 inode limit that we ran into is only 3% of the > number of inodes specified in the document (2^32 inodes in a 4 TiB > filesystem with 1KiB block sizes for 32-bit mode). Sure, but the default file system configs don't include 1k block sizes. There really is only one reason that I care about the 1k block size --- it's to make it easy to validate on an x86 architecture what happens when a file system with a default 4k block size is mounted on an architectures such as PowerPC or Itanium which has a page size of 16k or 64k. That is, to test the case where block size < page size. But we really don't encourage people use a 1k block size in production. And while it would make sense from a performance point of view to use a 16k or 64k block size file system on a PowerPC or Itanium system, people who care about making their file system portable across PowerPC and x86 (for example) will need to use a 4k block file system (since Linux doesn't support block size > page size). So using a 1k block file system on a terabyte file system is neither the default nor a sane thing to do. I'll look into making mke2fs handle this case more smoothly, but it's not something that I consider a high priority or something I would encourage as a realstic production use case. Cheers, - Ted