From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jim Subject: Re: snapshots changed behavior Date: Fri, 21 Oct 2011 14:29:11 -0400 Message-ID: <4EA1B9F7.1060001@webstarts.com> References: <4EA19E66.2020102@webstarts.com> <38803013.ZrEk6jGlKT@venice> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linux-btrfs@vger.kernel.org To: Goffredo Baroncelli Return-path: In-Reply-To: <38803013.ZrEk6jGlKT@venice> List-ID: Goffredo, Thank you very much for your reply. That was the information I needed to understand the behavior I was observing. Just to be sure that I understand correctly, you wrote: I am quite sure that the snapshot is NOT recursive. If a subvolume contains another subvolume, and you snapshot the former, the new subvolume shall not contain the "child" subvolume. when I snapshot /data, a subvolume I can see (but not enter) the subvolume /sites below it. When I snapshot subvolume /sites I can see and navigate through all directories (not subvolumes) below it. I am assuming that this is expected behavior. Thanks again for taking the time to help me here. Jim On 10/21/2011 01:53 PM, Goffredo Baroncelli wrote: > On Friday, 21 October, 2011 12:31:34 Jim wrote: >> Good afternoon btrfs list, > Hi Jim > >> about a month ago, when testing btrfs, I could create a snapshot with >> btrfs snap create and be able to drill down in the snapshot to find >> subvols and files below the snapshot level. I currently need to use >> btrfsctl -s to create snapshots and can no longer drill down through >> subvols in them. An example would be a file tree of /btrfs (subvol) >> /data (subvol) /sites (subvol) /0000 (directory) /files-in-dir. If I >> snapshot /btrfs/data I can open data and see /sites but can see nothing >> below /sites. However, if I snap /btrfs/data/sites I can drill down >> through all lower directories and files. In my past tests I was able to >> drill all the way down from the /btrfs/data snap. > I am quite sure that the snapshot is NOT recursive. If a subvolume contains > another subvolume, and you snapshot the former, the new subvolume shall not > contain the "child" subvolume. > > From what you report, it seems that /sites was a directory and not a snapshot. > > Pay attention that btrfsctl -s allow to take as source a directory. In this > case this program snapshot the subvolume which contains the subdirectory > passed as argument. > Instead the btrfs tool checked if the source is a subvolume. If not it raises > an error. > > I say so because the btrfctl behaviour confused a lot of people. > > In any case btrfs was never been capable to snapshot a directory. > >> Also, in the past, a >> snap was definitely a sparse file and was able to easily be moved, moved >> back, remounted and used. Currently, the useful file /btrfs/data/sites >> contains 5GB of data and both shows and moves as 5GB of data, not like a >> sparse file. Am I misusing the filesystem, or improperly using the >> commands? Or have changes been made to the functionality which I >> missed? > It is not allowed to move files between subvolume. The mv command in this case > copies the files and removes the original ones. > > From what you wrote it seems that (for mistake) you thought that a directory > was a subvolume. > >> Sorry to take your time on such a simple matter, but I need to >> understand how to best use the filesystem. Thanks very much for your >> advice. >> Jim Maloney >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html