From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josef Bacik Subject: Re: [RFC] make btrfs-image work Date: Tue, 19 Jan 2010 21:37:36 -0500 Message-ID: <20100120023736.GB16384@localhost.localdomain> References: <20100119160417.GA16384@localhost.localdomain> <3d0408631001191828v65fbb983w482f478b5ed92bbf@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: Josef Bacik , linux-btrfs@vger.kernel.org To: "Yan, Zheng " Return-path: In-Reply-To: <3d0408631001191828v65fbb983w482f478b5ed92bbf@mail.gmail.com> List-ID: On Wed, Jan 20, 2010 at 10:28:01AM +0800, Yan, Zheng wrote: > On Wed, Jan 20, 2010 at 12:04 AM, Josef Bacik wrot= e: > > Hello, > > > > btrfs-image would be very helpful for debugging some users problems= that we > > can't reproduce ourselves, but every image that i try and re-create= with > > btrfs-image makes btrfs panic. =A0This is because we zero out the s= uperblocks > > chunk array and re-create our uuid. =A0This means that we end up no= t being able to > > read the chunk tree on mount, and then even if we could the uuid's = of the > > metadata we read back wouldn't match the uuid of the device. =A0The= way I've fixed > > this is to just spit the metadata back onto the disk exactly the wa= y we got it. > > The caveat to this I think is that if we try to image a multi-devic= e setup that > > it won't work right unless we have a multi-device setup to restore = the image > > onto. =A0I'm not sure if thats the goal or not. =A0This patch makes= the single disk > > case work fine for me. =A0Let me know what you think. =A0Thanks, > > >=20 > The goal of btrfs-image is create image that can be examined by btrf= sck and > btrfs-debug-tree. btrfs-image creates metadata image for btrfs' logic= al address > space. So your patch only works for the uncommon case that btrfs' log= ical > address is mapped to offset of device. >=20 Ok, but I think it would be helpful to be able to restore the fs onto a= device and still be able to use it like a normal fs so we can debug other type= s of problems. But I don't really care that much so if that wasn't the inte= nded goal I'll find something else to work on. Thanks, Josef -- 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