Andrey V. Elsukov wrote this message on Mon, Aug 25, 2014 at 19:02 +0400: > On 25.08.2014 18:40, Marcel Moolenaar wrote: > >> Also, now FreeBSD 11.0 uses different first usable LBA. By default it is > >> 4k aligned. And this creates some incompatibility with older versions. > >> You can't do `gpart restore` and get the same table, as you had on older > >> system. > > > > It sounds restore is broken then. The restore command > > cannot ever assume anything about the GPT. Including > > the tool that created the GPT. In order to restore a > > GPT, it must be properly backed-up. The backup header > > and table should suffice most of the time for that > > purpose as it's a replica, but as soon as meta-data is > > missing and the restore command has to guess, things > > will go wrong. > > `gpart restore` just uses a number of commands to geom_part(4) to create > partition table similar to what was backed up. If your partition table > on the old system had a partition that starts from LBA 34, now `gpart > create` isn't able to create such partition table. Because by default > the first usable LBA is 40. Luckily, gpart restore won't work: # gpart backup /dev/md0 GPT 4 1 freebsd-ufs 8 262144 # gpart restore md1 < /tmp/foob.gpt.back gpart: entries '4': Invalid argument So, we're somewhat safe, guess gpart restore needs to learn how to handle entries properly.... We should fix this, since other OS's might not use 128 for entries.. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."Received on Mon Aug 25 2014 - 15:38:43 UTC
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