May 2007 - Darwin-kernel - lists.apple.com

Re: buildin kernel 8.9.0
by cristian pancià 02 May '07

02 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=Xw+U5CYpWU+5uYT4dcqVYOCq8H9FNUBg1ZPNwgPa+YajF2poptltzAwtoyBuR4JMY2pgmigHNXhoEokhjb1GCz7XhEOPjo99TXGgTFX/+QEYdMFnafkPPohui9lqdLnKWvD7kRX56C1GRQj7XOv96+ym/s8eFzKpkKgEFZYfutI= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:references; b=VduMAaYuIT3Vz4MrWGQIHaa4BzRey4pC6BZtAF+e0kj/2crLo38bGc/PezbFtF8kx+//fIvzV1Eaw+RDZ6WfACOU9i9oGFThjs11rc2Trqc6dMTKTNRwLH2b6aWtlH7dwxBCchC6NjXXt4bEwjUiXME2jTggg9t43OR6R0fCU/c= _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

1 0

Re: Info needed for File System Development
by Terry Lambert 01 May '07

01 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Hi, This is a hard nut to crack on UNIX-style systems. - Here's the documentation he probably wants: And here's sample code for one: -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… On May 1, 2007, at 7:30 AM, Andreas Fink wrote: On 01.05.2007, at 10:18, Anton Altaparmakov wrote: On 30 Apr 2007, at 23:33, John Davidorff Pell wrote: This sounds much like you're trying to add full journaling to HFS +. Is this a fair characterisation? I don't think so. He is effectively describing what Leopard's Time Machine or Legato's Networker backup solution provide (implemented differently) so they seem to be reinventing the wheel somewhat... ... a wheel which was invented ages ago on Digital's VMS filesystem. File versioning. The primary problem is that this worked for VMS because VMS did globbing in the kernel, rather than in user space in the shell. Add to that that Files-11 is a record oriented rather than byte-stream oriented, so you could share records between various versions, with minimal data replication. This combination of factors is why most attempts at supporting versioning in FS's on UNIX-style systems hasn't been very satisfying; it's nearly impossible to get the implied "most recent version" version number semantic right without pushing the version suffix matching down into the kernel, and even so, you are stuck with copying around whole files. CDP is an interesting idea (even more interesting if you happen to sell storage systems that you want people to need... 8^)), though almost all implementations I'm aware of that try to implement what they call "real CDP" as opposed to snapshots or something similar ("near CDP") have application specific knowledge. This solves the data atomicity problem: all of your data is consistent across the snapshot at any given time, and as long as you use standard data integrity techniques, like two stage commits with intention logging, you can replicate and recover all of your state. General practical use is for very expensive to lose data, plus replication, either for HA, or for off-site data safety. I think for what Shailesh wants to do, he's going to be writing his own block storage driver, rather than putting in a shim; it's more akin to implementing a software RAID solution than it is snapshots or versioning. The only way that's going to work is if he owns the read disks and exports something that looks like a real disk to the OS. Basically, he's both a consumer of an IOMedia object, and a producer of IOMedia objects; on Mac OS X, this is called a "filter-scheme driver". <http://developer.apple.com/documentation/DeviceDrivers/Conceptual/MassStora… > <http://developer.apple.com/samplecode/SampleFilterScheme/index.html#//apple… > The downside is going to be that he's going to have a hard time slapping this on top of a running system, without effectively taking over direct management of the disk, and if he's doing this for HFS, to do something like directory folding or file hiding for his magic metadata will mean understanding a lot more about the structure of HFS than maybe he wants to. This email sent to site_archiver(a)lists.apple.com

1 0

Re: buildin kernel 8.9.0
by Rick Macklem 01 May '07

01 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Mon, 30 Apr 2007, cristian panci? wrote: gcc kextsymboltool.c -o kextsymboltool To be honest, I've never had any luck trying to build kextsymboltool from sources. (I think you need to use xcode, but I never got that to work, either:-) The good news is that you don't need it to build a bootable kernel, you only need it for building kexts. If you are working on an Intel Mac, you were able to grab binaries of the extra build stuff from www.macosforge.org (not sure if they are currently there), which included a working kextsymboltool binary. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com If you grab ftp://ftp.cis.uoguelph.ca/pub/nfsv4/darwin-port/xnu-client.tar.gz there are some notes in the tarball on how I build kernels. (Doesn't help w.r.t. building kextsymbltool from sources, though.) Good luck with it, rick

1 0

Re: Info needed for File System Development
by Andreas Fink 01 May '07

01 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

1 0

Re: Info needed for File System Development
by Anton Altaparmakov 01 May '07

01 May '07

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Hi, Best regards, Anton JP On Apr 30, 2007, at 5:41 AM, Shailesh Parulekar wrote: Firstly,Thanks all for extending your help. Thanks again, --shailesh parulekar From: Michael Smith <drivers(a)mu.org> To: Shailesh Parulekar <smileyshailoo(a)hotmail.com> CC: darwin-kernel(a)lists.apple.com Subject: Re: Info needed for File System Development Date: Sun, 29 Apr 2007 14:43:39 +0930 On Apr 26, 2007, at 6:13 PM, Shailesh Parulekar wrote: What are the "needs of your product"? -- Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer, http://www.linux-ntfs.org/ _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… On 30 Apr 2007, at 23:33, John Davidorff Pell wrote: This sounds much like you're trying to add full journaling to HFS+. Is this a fair characterisation? I don't think so. He is effectively describing what Leopard's Time Machine or Legato's Networker backup solution provide (implemented differently) so they seem to be reinventing the wheel somewhat... I.e. you keep all changes to the file so you can go back in time to any particular version of the file that previously existed. So for example when you delete a file or it gets corrupt or when you simply modify a file and don't like the changes you can then get back the previous version(s) at will at the simple click of a button or two... About, need of our product:: At a very high level, I wish to intercept the I/Os (essentially Writes) made to a set of files and store the changes in my secondary storage so that in the event of machine crash user should be able to reconstruct his/her files with the help of the product. In general terminology it is Continuous Data Protection (C.D.P.) My intention is to track the block changes that happen to the files and have my meta data pointing to the old (changed) blocks so that I get to construct various versions of the files from my meta data. As and when plans are crystallized I will have more concrete questions to chalk down. For now I just need to get started with the Mac OS X Internals and think of possible avenues to meet my requirements. I need to develop a Filter driver to plug-in into the MAC File System in order to 'filter' the read/writes to the files and process the same as per the need of our product. = Mike This email sent to site_archiver(a)lists.apple.com

1 0