On Sat, 2007-10-20 at 18:09 +0400, Michael Tokarev wrote: > Doug Ledford wrote: > [] > > 1.0, 1.1, and 1.2 are the same format, just in different positions on > > the disk. Of the three, the 1.1 format is the safest to use since it > > won't allow you to accidentally have some sort of metadata between the > > beginning of the disk and the raid superblock (such as an lvm2 > > superblock), and hence whenever the raid array isn't up, you won't be > > able to accidentally mount the lvm2 volumes, filesystem, etc. (In worse > > case situations, I've seen lvm2 find a superblock on one RAID1 array > > member when the RAID1 array was down, the system came up, you used the > > system, the two copies of the raid array were made drastically > > inconsistent, then at the next reboot, the situation that prevented the > > RAID1 from starting was resolved, and it never know it failed to start > > last time, and the two inconsistent members we put back into a clean > > array). So, deprecating any of these is not really helpful. And you > > need to keep the old 0.90 format around for back compatibility with > > thousands of existing raid arrays. > > Well, I strongly, completely disagree. You described a real-world > situation, and that's unfortunate, BUT: for at least raid1, there ARE > cases, pretty valid ones, when one NEEDS to mount the filesystem without > bringing up raid. Raid1 allows that. Name one. -- Doug Ledford <dledford@xxxxxxxxxx> GPG KeyID: CFBFF194 http://people.redhat.com/dledford Infiniband specific RPMs available at http://people.redhat.com/dledford/Infiniband
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