Differences

This shows you the differences between two versions of the page.

Link to this comparison view

fdisk [2013/08/22 12:04] (current)
Line 1: Line 1:
 +====== fdisk ======
  
 +  * [[Filesystems]]
 +  * [[NetBSD]]
 +  * [[OpenBSD]]
 +  * [[disklabel]]
 +  * [[newfs]]
 +  * [[raidctl]]
 +  * [[softraid]]
 +  * [[sysctl]]
 +
 +  * [[http://​www.daemonforums.org/​showthread.php?​t=2824|HOWTO:​ reformat a USB flash drive in NetBSD]]
 +==== Linux and NetBSD Partitioning ====
 +
 +Partitioning drives in NetBSD is different than Linux. ​ In Linux, there is one MBR table with partitions for as many filesystems as you would like.
 +
 +In NetBSD, one partition is created from the original four that are found with an MBR table, then disklabel is used to create it's own form of partitions called slices within the MBR partition.
 +
 +In other words, running ''​fdisk''​ in Linux on a hard drive with NetBSD installed, would show only one partition created.
 +
 +=== netbsd-vm Example ===
 +
 +== Linux ==
 +
 +The drives here are IDE drives, so they show up as ''​wdX''​ instead of ''​sdX''​ in NetBSD.
 +
 +Here's what ''​fdisk -l /​dev/​sda''​ would return in Linux, for the MBR partitions:
 +
 +<​code>​
 +Disk /dev/sda: 12.9 GB, 12884901888 bytes, 25165824 sectors
 +Units = sectors of 1 * 512 = 512 bytes
 +Sector size (logical/​physical):​ 512 bytes / 512 bytes
 +I/O size (minimum/​optimal):​ 512 bytes / 512 bytes
 +Disk identifier: 0x00000000
 +
 +   ​Device Boot      Start         ​End ​     Blocks ​  ​Id ​ System
 +/​dev/​sda1 ​  ​* ​       2048    25165823 ​   12581888 ​  ​a9 ​ NetBSD
 +</​code>​
 +
 +== NetBSD ==
 +
 +''​fdisk wd0''​ will also show the MBR partitions:
 +
 +<​code>​
 +Disk: /dev/rwd0d
 +NetBSD disklabel disk geometry:
 +cylinders: 24966, heads: 16, sectors/​track:​ 63 (1008 sectors/​cylinder)
 +total sectors: 25165824
 +
 +BIOS disk geometry:
 +cylinders: 1024, heads: 255, sectors/​track:​ 63 (16065 sectors/​cylinder)
 +total sectors: 25165824
 +
 +Partitions aligned to 2048 sector boundaries, offset 2048
 +
 +Partition table:
 +0: NetBSD (sysid 169)
 +    start 2048, size 25163776 (12287 MB, Cyls 0-1566/​127/​33),​ Active
 +1: <​UNUSED>​
 +2: <​UNUSED>​
 +3: <​UNUSED>​
 +Bootselector disabled.
 +First active partition: 0
 +</​code>​
 +==== Format a NetBSD Hard Drive ====
 +
 +There are a lot of different device names for the same thing, so to keep things simple, just use ''​sd0'',​ ''​sd1'',​ etc. for the MBR partitions.
 +
 +Display status of a disk:
 +
 +<​code>​
 +fdisk sd0
 +</​code>​
 +
 +== Initialization ==
 +
 +Use ''​fdisk''​ to create an MBR partition table (same as on Linux).
 +
 +Do this before disklabel or newfs:
 +
 +<​code>​
 +fdisk -u sd0
 +</​code>​
 +
 +<​code>​
 +fdisk: primary partition table invalid, no magic in sector 0
 +Disk: /dev/sd1
 +NetBSD disklabel disk geometry:
 +cylinders: 224, heads: 255, sectors/​track:​ 63 (16065 sectors/​cylinder)
 +total sectors: 3604865
 +
 +BIOS disk geometry:
 +cylinders: 1023, heads: 255, sectors/​track:​ 63 (16065 sectors/​cylinder)
 +total sectors: 1952448512
 +
 +Partitions aligned to 16065 sector boundaries, offset 63
 +
 +Do you want to change our idea of what BIOS thinks? [n] n
 +
 +Partition table:
 +0: <​UNUSED>​
 +1: <​UNUSED>​
 +2: <​UNUSED>​
 +3: <​UNUSED>​
 +Bootselector disabled.
 +No active partition.
 +Which partition do you want to change?: [none] 0
 +The data for partition 0 is:
 +<​UNUSED>​
 +sysid: [0..255 default: 169] 
 +start: [0..224cyl default: 63, 0cyl, 0MB] 
 +size: [0..224cyl default: 3604802, 224cyl, 1760MB] ​
 +bootmenu: [] 
 +
 +Partition table:
 +0: NetBSD (sysid 169)
 +    start 63, size 3604802 (1760 MB, Cyls 0-224/​100/​5)
 +        PBR is not bootable: All bytes are identical (0x00)
 +1: <​UNUSED>​
 +2: <​UNUSED>​
 +3: <​UNUSED>​
 +Bootselector disabled.
 +No active partition.
 +Which partition do you want to change?: [none] ​
 +
 +We haven'​t written the MBR back to disk yet.  This is your last chance.
 +Partition table:
 +0: NetBSD (sysid 169)
 +    start 63, size 3604802 (1760 MB, Cyls 0-224/​100/​5)
 +        PBR is not bootable: All bytes are identical (0x00)
 +1: <​UNUSED>​
 +2: <​UNUSED>​
 +3: <​UNUSED>​
 +Bootselector disabled.
 +No active partition.
 +Should we write new partition table? [n] y
 +</​code>​
 +
 +== Partition hard drive ==
 +
 +Edit the NetBSD partitions (slices):
 +
 +<​code>​
 +disklabel -i -I sd1
 +</​code>​
 +
 +<​code>​
 +Enter '?'​ for help
 +partition>​ d
 +Filesystem type [?] [4.2BSD]: 4.2BSD
 +Start offset ('​x'​ to start after partition '​x'​) [0c, 0s, 0M]: 
 +Partition size ('​$'​ for all remaining) [953344c, 1952448512s,​ 953344M]: $
 +partition>​ W
 +Label disk [n]? y
 +Label written
 +partition>​ Q
 +</​code>​