Amazon EBS Enables Live Volume Modifications with Elastic Volumes (opens in new tab)

(aws.amazon.com)

38 pointsUsu9y ago23 comments

23 comments

Earlier post: https://news.ycombinator.com/item?id=13641499

I haven't done this in AWS yet, but I've been growing mounted block devices/disks Google Cloud for a while now. It's more or less just like growing a disk on a SAN.

You still have to grow the filesystem it self though, so if you're trying to grow the root mount, using a partitioned disk, and not using an abstraction like LVM you will need to reboot to be able to use the full disk.

Glad to see AWS catch up in this area.

brazzledazzle9y ago

I wonder if Linux can mimic the technique Microsoft uses to grow volumes and filesystems on the fly. It's something I've missed on the occasion. It's pretty slick.

maccam949y ago

A number of Linux filesystems support online resize. See this handy chart: https://en.wikipedia.org/wiki/Comparison_of_file_systems#Res...

Nux9y ago

All my VMs have a separate /boot and ext4 as / (xfs would work, too).

With this setup - using KVM, mind you - I can change the disk size of the VM and resize the / filesystem inside by just using resize2fs, no need to reboot, umount or anything else.

1 more reply

Rapzid9y ago

It depends on the filesystem but yes, it can.

diziet9y ago

Finally, I presume this lets us resize EBS volumes without having to do things like this: https://matt.berther.io/2015/02/03/how-to-resize-aws-ec2-ebs...

moofight9y ago

Let's say I have an EBS volume of 500GB with 300GB of data. What happens if I mistakenly resize the EBS volume to 200GB? Do I get an error message or does part of my data get wiped out?

falsedan9y ago

Good news: you won't lose any data from resizing your EBS down.

Bad news: that's because you can't make your EBS smaller.

  > You can now increase volume size, adjust performance, or change the volume type while the volume is in use.

Note the absence of 'increase OR decrease volume size'.

moofight9y ago

Yes, you are absolutely right. "EBS volumes can only be increased, not decreased".

2 more replies

chillydawg9y ago

Tried this just now. Spun up 8GB ec2+ebs instance. Booted and logged in as root. Deleted the root partition using fdisk, carefully recreated it from the same starting sector but to new 100GB capacity (check lsblk output to confirm). Then resize2fs /dev/xvda1 my ext4 FS. All online, hot. Obviously it's risky, but you can take a snapshot of the EBS before starting. Seems very nice for the common use case of slowly growing storage needs that are best served by a simple disk.

piquadrat9y ago

As usual, Jeff Barr's blog post is much more informative than the announcement.

https://aws.amazon.com/blogs/aws/amazon-ebs-update-new-elast...

nidx9y ago

I've been procrastinating on moving our app to aws because this was not supported, I was going to have to rewrite some horrible code to support using s3 for scaling (EFS is not in the new Canada region). This should save me a few hundred hours!

social_quotient9y ago

So can I change to spinners at night with low I/O to save on daytime costs with higher SSD IOPs? "Automate" with lambda seems like it begging for cost optimization as well.

mwarkentin9y ago

I think you can only do this with gp2 and provisioned IOPS volumes.

In addition, you have to wait 6 hours before scaling again.

timborden9y ago

We went with EFS for our RethinkDB instances on EC2. Was set up as a big data store, so read latency wasn't really an issue. Works well.

But that was before this announcement...nice addition AWS EBS team!

j / k navigate · click thread line to collapse

23 comments

tomhoward9y ago

Earlier post: https://news.ycombinator.com/item?id=13641499

Cidan9y ago

I haven't done this in AWS yet, but I've been growing mounted block devices/disks Google Cloud for a while now. It's more or less just like growing a disk on a SAN.

Glad to see AWS catch up in this area.

brazzledazzle9y ago

I wonder if Linux can mimic the technique Microsoft uses to grow volumes and filesystems on the fly. It's something I've missed on the occasion. It's pretty slick.

maccam949y ago

A number of Linux filesystems support online resize. See this handy chart: https://en.wikipedia.org/wiki/Comparison_of_file_systems#Res...

Nux9y ago

All my VMs have a separate /boot and ext4 as / (xfs would work, too).

With this setup - using KVM, mind you - I can change the disk size of the VM and resize the / filesystem inside by just using resize2fs, no need to reboot, umount or anything else.

1 more reply

Rapzid9y ago

It depends on the filesystem but yes, it can.

diziet9y ago

Finally, I presume this lets us resize EBS volumes without having to do things like this: https://matt.berther.io/2015/02/03/how-to-resize-aws-ec2-ebs...

moofight9y ago

Let's say I have an EBS volume of 500GB with 300GB of data. What happens if I mistakenly resize the EBS volume to 200GB? Do I get an error message or does part of my data get wiped out?

falsedan9y ago

Good news: you won't lose any data from resizing your EBS down.

Bad news: that's because you can't make your EBS smaller.

  > You can now increase volume size, adjust performance, or change the volume type while the volume is in use.

Note the absence of 'increase OR decrease volume size'.

moofight9y ago

Yes, you are absolutely right. "EBS volumes can only be increased, not decreased".

2 more replies

chillydawg9y ago

piquadrat9y ago

As usual, Jeff Barr's blog post is much more informative than the announcement.

https://aws.amazon.com/blogs/aws/amazon-ebs-update-new-elast...

nidx9y ago

social_quotient9y ago

So can I change to spinners at night with low I/O to save on daytime costs with higher SSD IOPs? "Automate" with lambda seems like it begging for cost optimization as well.

mwarkentin9y ago

I think you can only do this with gp2 and provisioned IOPS volumes.

In addition, you have to wait 6 hours before scaling again.

timborden9y ago

We went with EFS for our RethinkDB instances on EC2. Was set up as a big data store, so read latency wasn't really an issue. Works well.

But that was before this announcement...nice addition AWS EBS team!

j / k navigate · click thread line to collapse