On 16/06/15 04:55, Andrew Stuart wrote:
Andrew: how do you specify the block storage to Amazon?
1: when you create an AMI (Amazon Machine Image, which is like a configuration
blueprint for creating VM's)
OR
2: when you launch an AMI from the command line you can override the device
mappings for that AMI
It is possible to override the device mappings when launching a VM using one of
the various command line tools such as ec2-run-instances. This link
http://docs.aws.amazon.com/AWSEC2/latest/CommandLineReference/ApiReference-cmd-RunInstances.html
explains the --block-device-mapping parameter.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html
The above link says:
"A block device mapping defines the block devices (instance store volumes and
EBS volumes) to attach to an instance. You can specify a block device mapping as
part of creating an AMI so that the mapping is used by all instances launched from
the AMI. Alternatively, you can specify a block device mapping when you launch an
instance, so this mapping overrides the one specified in the AMI from which you
launched the instance.”
also:
"Each instance that you launch has an associated root device volume, either an
Amazon EBS volume or an instance store volume. You can use block device mapping to
specify additional EBS volumes or instance store volumes to attach to an instance
when it's launched. You can also attach additional EBS volumes to a running
instance;”
*****Device naming
Amazon uses block device names of the form /dev/sdX
the root device is /dev/sda1
However, in many cases the kernel renames the device names from /dev/sdX to the
form /dev/xvdX (XVD being Xen Block Device). This may well be the case for what
we are doing but I haven’t found the hard evidence yet.
Further reading:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/RootDeviceStorage.html
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/device_naming.html
I guess English is ambiguous. I meant how do *you* specify *the* block
storage, i.e. can you post concrete commands (both inside and outside
and outside of rumprun)?
