Question: This is the first time I ordered a dedicated server with 3 HDDs and I am quite confused. My limited knowledge tells me that
- /dev/sda
- /dev/sdb
- /dev/sdc
are the 3 drives that I actually have.
But, using the command fdisk -l | grep ‘^Disk’ gives the following output:
Disk /dev/sda: 1000.2 GB, 1000204886016 bytesDisk identifier: 0x5413d59fDisk /dev/sdb: 1000.2 GB, 1000204886016 bytesDisk identifier: 0x541faf6aDisk /dev/sdc: 1000.2 GB, 1000204886016 bytesDisk identifier: 0x54145359Disk /dev/md2: 995.2 GB, 995237888000 bytesDisk identifier: 0x00000000Disk /dev/md1: 4291 MB, 4291756032 bytesDisk identifier: 0x00000000Disk /dev/mapper/sys1AP7-root: 990.9 GB, 990929485824 bytesDisk identifier: 0x00000000Disk /dev/md0: 536 MB, 536805376 bytesDisk identifier: 0x00000000Disk /dev/mapper/sys1AP7-vartmp: 2147 MB, 2147483648 bytesDisk identifier: 0x00000000Disk /dev/mapper/sys1AP7-tmp:
it appears I have more than 3 drives.
What exactly are the following?
- /dev/md2
- /dev/md1
- /dev/mapper/sys1AP7-root
- /dev/md0
- /dev/mapper/sys1AP7-vartmp
- /dev/mapper/sys1AP7-tmp
Edit: My config as I ordered it is suppose to be disk 1 and 2 in RAID1 setup, while disk 3 should be a standalone drive.
Answer: You have only 3 physical devices:
- /dev/sda
- /dev/sdb
- /dev/sdc
It is simply as by convention, IDE drives will be given device names /dev/hda to /dev/hdd.
Besides that you have logical RAID devices:
- /dev/md0
- /dev/md1
- /dev/md2
RAID (originally redundant array of inexpensive disks; now commonly redundant array of independent disks) is a data storage virtualization technology that combines multiple disk drive components into a logical unit for the purposes of data redundancy or performance improvement.
RAID needs a Linux kernel framework for mapping block devices onto higher-level virtual block devices, so-called device mapper:
- /dev/mapper