What is the maximum number of mounted volumes per Amazon EC2 instance?

Question

I am running Ubuntu Server 12.04 LTS as a guest operating system.

How many volumes can I connect to an instance? I am working on a project that will require each of our clients to have their own volume.

Amazon does not have dynamic volumes, so we need to create a new volume from the snapshot in order to enlarge the existing one. This operation requires server downtime and this is unacceptable. That's why we need one volume per client. With a physical server, I will put a 2 TB disk and use quotas, but so far we do not want to go this route.

Answer 1

There are actually no limits if you stick with Linux (Windows instances are limited to 16 EBS volumes). You may need to change the device naming, then you can easily get up to 24 volumes:

/dev/sdf1 /dev/sdf5 /dev/sdf9 /dev/sdg4 /dev/sdg8 /dev/sdh3 /dev/sdf2 /dev/sdf6 /dev/sdg1 /dev/sdg5 /dev/sdg9 /dev/sdh4 /dev/sdf3 /dev/sdf7 /dev/sdg2 /dev/sdg6 /dev/sdh1 /dev/sdh5 /dev/sdf4 /dev/sdf8 /dev/sdg3 /dev/sdg7 /dev/sdh2 /dev/sdh6 

For more information, review the documents: Attaching a volume to an instance .

Answer 2

AWS says there is a limit of 40 volumes for Linux and 26 or 16 for Windows with this warning for everyone. Attaching more than * volumes to an instance * is only supported with maximum efficiency and is not guaranteed.

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/volume_limits.html

Answer 3

To build moosgummi's answer, AWS allows a wide range of device block names to be used. See Related Documentation here in the “Specifying Block Device Display” section.

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html

The mount point of the EBS volume should start with / dev /, and then indicate “hd” or “sd” (2), then from a to z (26), and then from 1 to 15 or without a number (16). These options give 2 x 26 x 16 = 832 name options . (More than moosgummi suggested 24.) But be careful to avoid conflicts with the root device (sda1) or other default values ​​(sda [1-15]).

Device Name Limitations is the only limitation that I know about the total number of EBS volumes mounted. But I have never tried more than a few times.