From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:56419 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759873Ab2EQOpj (ORCPT ); Thu, 17 May 2012 10:45:39 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1SV1xR-00056Z-BU for linux-btrfs@vger.kernel.org; Thu, 17 May 2012 16:45:37 +0200 Received: from cpc4-stap10-2-0-cust490.12-2.cable.virginmedia.com ([217.137.143.235]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 17 May 2012 16:45:37 +0200 Received: from m_btrfs by cpc4-stap10-2-0-cust490.12-2.cable.virginmedia.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 17 May 2012 16:45:37 +0200 To: linux-btrfs@vger.kernel.org From: Martin Subject: SSD format/mount parameters questions Date: Thu, 17 May 2012 15:45:27 +0100 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: For using SSDs: Are there any format/mount parameters that should be set for using btrfs on SSDs (other than the "ssd" mount option)? General questions: How long is the 'delay' for the delayed alloc? Are file allocations aligned to 4kiB boundaries, or larger? What byte value is used to pad unused space? (Aside: For some, the erased state reads all 0x00, and for others the erased state reads all 0xff.) Background: I've got a mix of various 120/128GB SSDs to newly set up. I will be using ext4 on the critical ones, but also wish to compare with btrfs... The mix includes some SSDs with the Sandforce controller that implements its own data compression and data deduplication. How well does btrfs fit with those compared to other non-data-compression controllers? Regards, Martin