Carl-Daniel, >From a high level, there is definitely interest in any solution that has the ability to get around the need for proprietary binary drivers that enable driver based RAID solutions, and enables common metadata formats like DDF. The main features of interest from a server perspective in any RAID solution (Software or Hardware) are - Full RAID support (0/1/5/10) - DDF - OS RAID Management / configuration - Robust error handling - Installable to the RAID logical device. Need the ability for Linux to understand the RAID array prior to installation, and not force the user to add RAID support post installation (protected boot arrays) Enhanced MD has accomplished these features through E-MD and E-MDADM, however, it has not met the needs of the community from an architectural standpoint. We're looking for something that meets both sides of this equation. Thanks Andre -----Original Message----- From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-owner@vger.kernel.org] On Behalf Of Carl-Daniel Hailfinger Sent: Friday, April 16, 2004 4:35 PM To: Linux Kernel Mailing List Cc: Linux RAID Mailing List Subject: [RFC] Enhanced MD / alternatives in userspace Hi, during development of raiddetect I asked myself if this tool could be extended to set up not only the classic vendor ATARAID devices, but also things like Adaptec ASR (HostRAID) and DDF based RAID formats. Raiddetect is a utility which searches all disks for known RAID superblocks/metadata and parses the contents for validity. The results of this scan can either be outputted to the console or used to tell dm/md to set up the RAID devices. The newest version of raiddetect was posted to linux-kernel a few minutes ago and I will provide a web home for it soon. So far, the development of raiddetect is at a stage where I can find (and mostly validate) the metadata of all ATARAID devices recognized by 2.4 kernels. Adding ASR and DDF detection should be relatively easy since I tried to make the code moular and extensible. Assuming the on-disk format of RAID5 et al. does not differ between the Linux md implementation and e.g. DDF (modulo some offset and different superblocks), DDF support is possible today with combinations of plain MD and DM. No additional kernel code needed at all. Simply teach raiddetect to understand the DDF metadata and pass this information to MD in a format md understands. The DDF metadata can be masked away from MD by using DM so you don't have to worry about it being trashed. Since this is marked as [RFC], please comment on its (in-)feasibility. Regards, Carl-Daniel -- http://www.hailfinger.org/ - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
