Re: softraid and 4096-byte sectors 'fixed'
Kenneth R Westerback wrote: CAVEAT: The metadata version has changed so new volumes you create will not be loadable on boxes running older versions of OpenBSD. CAVEAT: You can't rebuild a volume created with *only* 512-byte devices onto a 4K-sector device. The volume must be created with at least one 4K device to start with. given these two caveats, is it reasonable to continue using the old metadata format for 512 byte arrays? perhaps for some time anwyay.
Re: softraid and 4096-byte sectors 'fixed'
On 22 July 2015 at 12:36, Ted Unangst t...@tedunangst.com wrote: Kenneth R Westerback wrote: CAVEAT: The metadata version has changed so new volumes you create will not be loadable on boxes running older versions of OpenBSD. CAVEAT: You can't rebuild a volume created with *only* 512-byte devices onto a 4K-sector device. The volume must be created with at least one 4K device to start with. given these two caveats, is it reasonable to continue using the old metadata format for 512 byte arrays? perhaps for some time anwyay. I have thought of that. An alternative would be to make all version 6 volumes be 4096-byte sector devices and thus eliminate the can I rebuild using this 4K disk or not? question. Ken
Re: softraid and 4096-byte sectors 'fixed'
On Wed, Jul 22, 2015 at 6:43 PM, Kenneth Westerback kwesterb...@gmail.com wrote: On 22 July 2015 at 12:36, Ted Unangst t...@tedunangst.com wrote: Kenneth R Westerback wrote: CAVEAT: The metadata version has changed so new volumes you create will not be loadable on boxes running older versions of OpenBSD. CAVEAT: You can't rebuild a volume created with *only* 512-byte devices onto a 4K-sector device. The volume must be created with at least one 4K device to start with. given these two caveats, is it reasonable to continue using the old metadata format for 512 byte arrays? perhaps for some time anwyay. I have thought of that. An alternative would be to make all version 6 volumes be 4096-byte sector devices and thus eliminate the can I rebuild using this 4K disk or not? question. Great work! I'm curious how complex would be to add support for rebuild with 4k drive into array with 512b drives so far? The diff looks like you will need to modify some metadata on 512b drives to makes sectors look like 4k, but otherwise it does not look like impossible job. I don't mean that as a criticism, I'm glad you have done this job since it's inspiring for my ongoing add checksums to SR RAID 1 hobby task here. While working on this btw, I've been always wondering if 512b drives are the only supported option or not... Thanks! Karel
Re: softraid and 4096-byte sectors 'fixed'
On 22 July 2015 at 18:27, Karel Gardas gard...@gmail.com wrote: On Wed, Jul 22, 2015 at 6:43 PM, Kenneth Westerback kwesterb...@gmail.com wrote: On 22 July 2015 at 12:36, Ted Unangst t...@tedunangst.com wrote: Kenneth R Westerback wrote: CAVEAT: The metadata version has changed so new volumes you create will not be loadable on boxes running older versions of OpenBSD. CAVEAT: You can't rebuild a volume created with *only* 512-byte devices onto a 4K-sector device. The volume must be created with at least one 4K device to start with. given these two caveats, is it reasonable to continue using the old metadata format for 512 byte arrays? perhaps for some time anwyay. I have thought of that. An alternative would be to make all version 6 volumes be 4096-byte sector devices and thus eliminate the can I rebuild using this 4K disk or not? question. Great work! I'm curious how complex would be to add support for rebuild with 4k drive into array with 512b drives so far? The diff looks like you will need to modify some metadata on 512b drives to makes sectors look like 4k, but otherwise it does not look like impossible job. It is likely to be tricky and not guaranteed to work in all cases. But if everything is aligned compatibly, it might be possible. Ken I don't mean that as a criticism, I'm glad you have done this job since it's inspiring for my ongoing add checksums to SR RAID 1 hobby task here. While working on this btw, I've been always wondering if 512b drives are the only supported option or not... Thanks! Karel
