zap (destroy) GPT and MBR data structures
sgdisk --zap-all /dev/sdb
create largest possible new partition
sgdisk --largest-new=1 /dev/sdb
check partition table integrity
sgdisk --verify /dev/sdb
print partition table
sgdisk --print /dev/sdb
I've done a pretty major overhaul to the article over the past week. Please check it for accuracy. One of my goals to was add a thread of continuity to the article so it reads as complete work rather than as a hodgepodge of advice. I feel that mixing formatting types and utils for example is confusing to newbies. I recommend sticking with GTP as you can see in the text.Graysky (talk) 23:22, 5 October 2013 (UTC)
RAID 1 and Stride/Stripe
The section "Build the Array" mentions "In a RAID1 the chunk switch is actually not needed." and mdadm outputs "chunk size ignored for this level". cat /proc/mdstat outputs "65536KB chunk" regardless of what chunk size was chosen during creating.
Yet the section "Calculating the Stride and Stripe-width" has an example for RAID1 and uses a 64KB chunk size for calculating it. What is this math based on if it is impossible to choose a chunk size for RAID1 —This unsigned comment is by Malstrond (talk) 13 January 2014. Please sign your posts with ~~~~!
- Note that
/proc/mdstathas two "chunks" listed:
- Note that
Personalities : [raid6] [raid5] [raid4] md0 : active raid6 sda2 sdb2 sde2 sdd2 sdc2 2929501200 blocks super 1.2 level 6, 16k chunk, algorithm 2 [5/5] [UUUUU] bitmap: 1/8 pages [4KB], 65536KB chunk
Subsituting one identical disk from another
It's useful to use sfdisk -d /dev/sda | sfdisk /dev/sdb for copy the partition from one of the disks of the raid to the replacing disk. External references: http://www.howtoforge.com/replacing_hard_disks_in_a_raid1_array. If you don't use sfdisk, then you could receive the error: mdadm: /dev/sdb1 not large enough to join array —This unsigned comment is by Xan (talk) 8 November 2014. Please sign your posts with ~~~~!
> To prevent possible issues each device in the RAID should be securely wiped.