From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephane Chazelas Subject: cloning single-device btrfs file system onto multi-device one Date: Mon, 21 Mar 2011 16:24:50 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: linux-btrfs@vger.kernel.org Return-path: List-ID: Hiya, I'm trying to move a btrfs FS that's on a hardware raid 5 (6TB large, 4 of which are in use) to another machine with 3 3TB HDs and preserve all the subvolumes/snapshots. Is there a way to do that without using a software/hardware raid on the new machine (that is just use btrfs multi-device). If fewer than 3TB were occupied, I suppose I could just resize it so that it fits on one 3TB hd, then copy device to device onto a 3TB disk, add the 2 other ones and do a "balance", but here, I can't do that. I suspect that if compression was enabled, the FS could fit on 3 TB, but AFAICT, compression is enabled at mount time and would only apply to newly created files. Is there a way to compress files already in a btrfs filesystem? Any help would be appreciated. Stephane