Btrfs implements native functionality for file & directory snapshots. These snapshots (at the least) have the capability for user/group/other-specific access-controls. [1]
As such, rollbacks to factory defaults, user data protection, et al., can all be properly managed with Btrfs in and of itself. Fewer filesystems lowers complexity. Greater degrees of simplicity and utility should be reasons in and of themselves for focusing solely upon Btrfs as a successor filesystem for Moblin-2.0's current reliance upon ext3. [1] http://btrfs.wiki.kernel.org/index.php/Btrfs_design#Snapshots_and_Subvolumes Peace, Jed Cousin "Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." --Antoine de Saint Exupéry -- 2009/9/25 Wei, James <james....@intel.com>: > As mentioned in Alan's mail, with UnionFS, we can easily reset the device to > factory default. And also, it can make backup/restore to work with little > byte transferring. > > We can make the factory default system with SquashFS as read only. And any > changes and user data are stored with btrfs which is writable. For backup and > restore, we only need to handle the data in btrfs partition. > > James > > -----Original Message----- > From: Arjan van de Ven [mailto:ar...@linux.intel.com] > Sent: 2009年9月25日 17:42 > To: Wei, James > Cc: Olsen, Alan R; dev@moblin.org > Subject: Re: [Moblin Dev] will moblin ever be able to use ext4? > > Wei, James wrote: >> As for UnionFS, will it be used in Moblin with btrfs+squashFS later? > > I can't see a reason why we would. > I can't even see a reason for squashfs either btw, btrfs has compression > built in ... > >> >> -----Original Message----- >> From: dev-boun...@moblin.org [mailto:dev-boun...@moblin.org] On Behalf Of >> Arjan van de Ven >> Sent: 2009年9月25日 14:34 >> To: Olsen, Alan R >> Cc: dev@moblin.org >> Subject: Re: [Moblin Dev] will moblin ever be able to use ext4? >> >> Olsen, Alan R wrote: >>> Ext4 would not be difficult to add. Ext4 is a rather young filesystem, so >>> there has not been a big rush to adopt it. >> >> that has not been Moblin's motivation. >> We did not see enough value in it to change to it. >> BTRFS has this extra value that makes it interesting to us. >> >> >>> UnionFS used to be a part of the builds as well. It was very useful in >>> adding "reset to factory default" to the filesystem. (The way you make it >>> work is you have a base partition that is marked read only and another >>> added on top of that one with read/write. Any additions get written to the >>> second partition. If things get messed up you just nuke the second >>> partition and things are reset back to start.) >> >> it hasn't been part of Moblin 2.0 >> >> >>> Hopefully btrfs will stabilize soon. It looks very promising. Not certain >>> how much overhead there is to make it work. Might be a wee bit of overkill >>> on a handheld device. >> >> If Moblin switches to it, we'll switch to it for all types of devices. >> Right now things look very good in that area, we haven't found a showstopper >> yet... >> The switch isn't for the upcoming 2.1 release, but for the Q1/2010 releasse. >> >> >> _______________________________________________ >> Moblin dev Mailing List >> dev@moblin.org >> >> To manage or unsubscribe from this mailing list visit: >> http://lists.moblin.org/listinfo/dev or your user account on >> http://moblin.org once logged in. >> >> For more information on the Moblin Developer Mailing lists visit: >> http://moblin.org/community/mailing-lists > > _______________________________________________ > Moblin dev Mailing List > dev@moblin.org > > To manage or unsubscribe from this mailing list visit: > http://lists.moblin.org/listinfo/dev or your user account on > http://moblin.org once logged in. > > For more information on the Moblin Developer Mailing lists visit: > http://moblin.org/community/mailing-lists _______________________________________________ Moblin dev Mailing List dev@moblin.org To manage or unsubscribe from this mailing list visit: http://lists.moblin.org/listinfo/dev or your user account on http://moblin.org once logged in. For more information on the Moblin Developer Mailing lists visit: http://moblin.org/community/mailing-lists
