EBS volumes are used to provide raw storage disk devices to SoftNAS.  EBS volumes are attached to the SoftNAS instance using the AWS console.

 

If you attach EBS volumes using the default naming scheme suggested in the AWS Console, which is /dev/sd[f-p], you cannot further assign any other device name via EBS. When you use these "base names" without any numeric identifiers, you cannot use the full range of EBS volume names, such sda1 or sda2 as described further below. So, in order to overcome the limitation of AWS you have to use device names in the form:

 

/dev/sd[f-p][1-15]

 

Even though a-z may appear to work, use of those device names is not supported, and AWS might be using a-g and q-z range at some stage for something else, so for now, it's a good idea to stick with the device names from [f-p][1-15] when attaching EBS volumes via AWS console.

 

For example: USE: /dev/sdf1, /dev/sdf2, /dev/sdf3 ... /dev/sdp14, /dev/sdp15

 

DO NOT USE the /dev/sdf or /dev/sdp base device names, or you will limit the number of EBS volumes that can be attached to a maximum of 25 disks.  [F - P ] should always be followed by a number, or you will restrict your instance's EBS add-on volumes.

 

This means you can assign 154 extra disks to an instance for a maximum of 154 TB of storage space (Note: you may required approval by AWS Support to go beyond the initial 20 TB limit default for your account).

 

EBS to Linux Device Mapping Table

 

EBS Mount SoftNAS Linux Mapping

 

/dev/sda1 /dev/xvde1 (Root Disk - 30 GB, do not use or partition)

 

/dev/sdf1 ... 15            /dev/xvdj1 ... xvdj15

 

/dev/sdg1 ... sdg15      /dev/xvdk1 ... xvdk15

 

/dev/sdh1 ... 15           /dev/xvdl1 ... 15

 

/dev/sdi1 ... 15 /          dev/xvdm1 ... 15

 

/dev/sdj1 ... 15           /dev/xvdn1 ... 15

 

/dev/sdk1 ... 15           /dev/xvdo1 ... 15

 

/dev/sdl1 ... 15           /dev/xvdp1 ... 15

 

/dev/sdm1 ... 15          /dev/xvdq1 ... 15

 

/dev/sdn1 ... 15           /dev/xvdr1 ... 15

 

/dev/sdo1 ... 15           /dev/xvds1, ... 15

 

/dev/sdp1 ... 15           /dev/xvdt1 ... 15