I recently set up a raid6. However, various instructions found online take different ways about it.
Some don’t make partitions. Some don’t set flags on parted. Etc…
I largely followed this guide: How To Create RAID Arrays with mdadm on Ubuntu 18.04 | DigitalOcean
And ended up with this:
~$ lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT
sda 5.47T disk
└─sda1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sdb 5.47T disk
└─sdb1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sdc 5.47T disk
└─sdc1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sdd 5.47T disk
└─sdd1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sde 5.47T disk
└─sde1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sdf 5.47T disk
└─sdf1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sdg 5.47T disk
└─sdg1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
sdh 5.47T disk
└─sdh1 5.47T linux_raid_member part
└─md0 43.8T ext4 raid6 /data
And I don’t know if this is good or not.
Printing one of the disks gives:
(parted) print
Model: ATA WDC <REMOVED> (scsi)
Disk /dev/sdh: 6.0TB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 6.0TB 6.0TB raid
And in fdisk:
Command (m for help): print
Disk /dev/sdh: 5.47 TiB, 6000900661248 bytes, 11719409651 sectors
Disk model: WDC <REMOVED>
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: CA0B5B87-6697-4350-A772-D48444119ABC
Device Start End Sectors Size Type
/dev/sdh1 2048 11719409651 11719409651 5.47T Linux RAID
I see other guides saying to give each disk a primary partition. Is this needed if they’re going to be raid?
Honestly, this is all way too confusing, with all these guides that each leaves different things out…
Any advice would be appreciated. Is this the way to do it? Am I missing something crucial by not setting a filesystem? Something else?
I just wanted to test using mdadm, never done it before… and there’s just so much conflicting info out there.