I purchased an external HD that was “mac compatable” but I used it with a linux system and used fdisk to put two partitions on it.<\/p>\n
Later on, I wanted to use gparted to easily resize one of the partitions, but it refused to see any partitions at all on the disk.<\/p>\n
fdisk could still see them just fine, but reported “Partition type: mac”<\/p>\n
It turns out that the problem was that the disk originally came with a mac partition table in addition to (right after) the regular MBR Master Boot Record.<\/p>\n
I noticed that the first partition didn’t actually start until 63 sectors into the disk (at the beginning of the 2nd cylinder). So I used DD to copy the first cylinder to a file: Looking at that bin file in an editor, I saw the string “Apple_partition_map” which is a dead givaway of what the problem was.<\/p>\n So, I wrote out all zeros to the first cylinder: And then I copied the first sector (512 bytes) back from the firstCyl.bin file I had made: And it worked! Now gparted is no longer confused by the apple (mac) partition table that I zeroed out, and sees my partition.<\/p>\n","protected":false},"excerpt":{"rendered":" I purchased an external HD that was “mac compatable” but I used it with a linux system and used fdisk to put two partitions on it. Later on, I wanted to use gparted to easily resize one of the partitions, … Continue reading
\n
\n Device Boot Start End Blocks Id System
\n\/dev\/sdb1 63 1171893554 585946746 83 Linux
\n<\/code><\/p>\n
\n
\nsudo dd bs=512 count=62 if=\/dev\/sdb of=firstCyl.bin
\n62+0 records in
\n62+0 records out
\n31744 bytes (32 kB) copied, 0.000715733 s, 44.4 MB\/s
\n<\/code><\/p>\n
\n
\n sudo dd bs=512 count=62 if=\/dev\/zero of=\/dev\/sdb
\n62+0 records in
\n62+0 records out
\n31744 bytes (32 kB) copied, 0.00165608 s, 19.2 MB\/s
\n<\/code><\/p>\n
\n
\nsummetj@constantine:~$ sudo dd bs=512 count=1 if=firstCyl.bin of=\/dev\/sdb
\n1+0 records in
\n1+0 records out
\n512 bytes (512 B) copied, 0.00183878 s, 278 kB\/s
\n<\/code><\/p>\n