Long story short, we had issues installing linux on this system. It magically decided to work, but now I'm unsure about the hard drive partitioning. One hard drive has linux installed on it and the other is just for storage at the moment. It shows 2 partitions of 256GB each on a single drive when the hard drive is only 256GB in size. Is it confused somehow? Did we break it?Output from fdisk -lDisk /dev/sda: 256.1 GB, 256060514304 bytes255 heads, 63 sectors/track, 31130 cylinders, total 500118192 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000eef50   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *        2048      499711      248832   83  Linux/dev/sda2          501758   500117503   249807873    5  Extended/dev/sda5          501760   500117503   249807872   8e  Linux LVMDisk /dev/sdb: 256.1 GB, 256060514304 bytes255 heads, 63 sectors/track, 31130 cylinders, total 500118192 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00067612   Device Boot      Start         End      Blocks   Id  System/dev/sdb1              63   500118191   250059064+  83  LinuxDisk /dev/mapper/ubuntu--vg-root: 238.7 GB, 238723006464 bytes255 heads, 63 sectors/track, 29023 cylinders, total 466255872 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000Disk /dev/mapper/ubuntu--vg-root doesn't contain a valid partition tableDisk /dev/mapper/ubuntu--vg-swap_1: 17.1 GB, 17070817280 bytes255 heads, 63 sectors/track, 2075 cylinders, total 33341440 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x00000000Disk /dev/mapper/ubuntu--vg-swap_1 doesn't contain a valid partition table
Partitioning done incorrectly?
ubuntu;partition;system installation
/dev/sda2 is an extended partition./dev/sda5 is an logical partition which is placed inside the extended partition.Originally there could be only 4 partitions on a hard disk. To circumvent this, the extended partition was invented and further partitions, so called logical partitions, could be created inside the extended partition.The partitions 1-4 are always primary partitions or the extended partition. Partitions 5+ are logical partitions inside the extended partition.So everything is all right with your disk /dev/sda even if there are two 256 GB partitions - because one of them is inside the other.P.S. What I said is true for drives with an MBR partition table. AFAIK drives with GPT partitions don't have those limitations.