That virtualized Fishworks appliance got me thinking: What if you combined this with this? Yeah, managing Elastic Block Store devices would require some changes, but, if you needed a NAS for your EC2 instances…

Volumes that operate with 20 GB or less of modified data since their most recent Amazon EBS snapshot can expect an annual failure rate (AFR) of between 0.1% – 0.5%, where failure refers to a complete loss of the volume. This compares with commodity hard disks that will typically fail with an AFR of around 4%, making EBS volumes 10 times more reliable than typical commodity disk drives.

Because Amazon EBS servers are replicated within a single Availability Zone, mirroring data across multiple Amazon EBS volumes in the same Availability Zone will not significantly improve volume durability.

That last sentence makes it sound like there is a 0.1% – 0.5% chance of catastrophic data loss of many distinct EBS volumes in an availability zone. If that’s the case, that’s scary – off the top of my head, I’d say your run-of-the mill “Enterprise” SAN doesn’t have a one-in-two hundred risk of catastrophic failure per year.

More links, not all of which I’ve had a chance to fully digest yet:

• Feature Guide: Elastic Block Store
• Amazon EBS (Elastic Block Store) – Bring Us Your Data
• Amazon’s Elastic Block Store explained
• Why Amazon’s Elastic Block Store Matters
• Amazon EBS – Tool and Library Support
• Running MySQL on Amazon EC2 with Elastic Block Store

Well, perhaps a 64-bit AMI is forthcoming – I think this is still a beta program – and perhaps Sun’s just trying to save us a buck or two, since the cheapest 64-bit EC2 instance is four times as expensive per hour as the cheapest 32-bit instance.

The blog entry makes it sound like you no longer need to register with Sun to use OpenSolaris on EC2, but that doesn’t appear to be the case – I only see the AMI in my private instances, and the details on the image seem to confirm this.

I’m running an instance right now; it did seem to take an extra long time for the image to come up, even by EC2 standards, and ec2-describe-instances showed the instance as “running” for a long time before I could connect using SSH. But it’s up now, ZFS root and all:

-bash-3.2# uname -a
SunOS domU-12-31-38-00-28-35 5.11 snv_91 i86pc i386 i86xpv
-bash-3.2# zfs list
NAME USED AVAIL REFER MOUNTPOINT
mnt 106K 147G 18K /mnt
rpool 2.74G 6.86G 59K /rpool
rpool/ROOT 2.73G 6.86G 18K /rpool/ROOT
rpool/ROOT/opensolaris-1 2.73G 6.86G 2.72G legacy
rpool/ROOT/opensolaris-1/opt 12.9M 6.86G 12.9M /opt
rpool/export 37K 6.86G 19K /export
rpool/export/home 18K 6.86G 18K /export/home
swap 450M 9.89M 18K /swap
swap/swapfile 450M 460M 16K -


One curiosity:

-bash-3.2# pkg image-update
pkg: "image-update" option currently not supported on Amazon EC2. Please check out http://blogs.sun.com/ec2 for more details.


I must have missed those details…

Update: Here’s the reason why you can’t run “pkg image-update” from the Getting Started Guide for Amazon EC2: “pkg image-update – This command is currently not supported on Amazon EC2 since it modifies the kernel and ramdisk files resulting in non-bootable AMI. As we know, in the EC2 environment modifying the kernel and ramdisk is not permitted. In certain cases, if the user wants to enable this command, then the user can edit the /usr/bin/pkg file appropriately.” (Which makes sense.)

• Amazon Elastic Block Store goes live! (Yeah, that link’s dead – like I said, it was later deleted.) The RightScale folks appear to have inadvertently published a draft (on 8/8, the day after I left town) of their blog post designed to coincide with the release of Amazon’s Elastic Block Store for EC2. They later deleted it, but Google Reader kindly cached the post for me. I won’t repeat anything in the post, nor would I bank on anything written there – would you gamble anything important on a retracted post about a not-yet-released product? I will add one comment: Will EBS attract attention of the lawsuit kind from NetApp? (I mean that comment only partially in jest – and you’d probably have to have seen the original post to know what I’m talking about.)