Hi hugo On 01/07/2013 07:24 PM, Hugo Mills wrote: [...] >> print "Superblock #%d - %20d - '%s'"%(i,pos,sign) >> >> $ python extract-sign.py >> Superblock #0 - 65600 - '_BHRfS_M' > > 64 KiB OK, (above) > >> Superblock #1 - 67108928 - '_BHRfS_M' > > 256 MiB .... above is 64M, below is 256M ! > >> Superblock #2 - 274877907008 - '_BHRfS_M' > > 1 TiB > >> Superblock #3 - 1125899906842688 - '' > > 4 PiB > >> Superblock #4 - 4611686018427387968 - '' > > 16 EiB Not reachable in linux. There is a VFS limits to 8EB. > > >> To me it seems that in a 7TB filesystem there is only 3 superblocks. > > That would be as expected. How many on a 5 PiB filesystem, though? > Or a 20 EiB one? I wrote 7TB, but I meant 8EB. I first tried a test with 7TB and I wrote the email, but then I retested with 8EB and I corrected the email, forgetting some 7t instead of 8e... Anyway, if BTRFS would allow more than three super-block, in the 7TB case, the super-block at 1TB would appeared > > Hugo. > -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
