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Some have speculated that AWS Glacier is just a service that still stores information on Tape anyways. I remember when I saw a robotic tape storage machine at F

Some have speculated that AWS Glacier is just a service that still stores information on Tape anyways. I remember when I saw a robotic tape storage machine at Fermilab when the Tevatron was still active. That was awesome. They also had racks of tapes. See https://en.wikipedia.org/wiki/Amazon_Glacier https://en.wikipedia.org/wiki/Amazon_Glacier

rdtsc 9y ago
I am surprised that this hasn't been leaked with how many people work at Amazon. Would expect some anonymous post somewhere "Oh yeah we use X, Y and Z there"
cortesoft 9y ago
Given that you have to request access to your data, then wait a bit of time before you can download lends credence to it being tape based, or at least something similar.
- hinkley 9y ago
  the power density of these data centers is so high that power and cooling may be your limiting factor. In which case having racks of hard drives where most of them are powered off half of the time would be feasible. But then you have to schedule powering up the right racks for the current set of requests.
  - wlesieutre 9y ago
    See Facebook's "Cold Storage" systems for an example of this https://code.facebook.com/posts/1433093613662262 https://code.facebook.com/posts/1433093613662262 > To get the most data into this footprint, we needed high density, but we also needed to remain media-agnostic and low-frills. Using the theme that “less is more,” we started with the Open Vault OCP specification and made changes from there. The biggest change was allowing only one drive per tray to be powered on at a time. In fact, to ensure that a software bug doesn’t power all drives on by mistake and blow fuses in a data center, we updated the firmware in the drive controller to enforce this constraint. The machines could power up with no drives receiving any power whatsoever, leaving our software to then control their duty cycle. > Not having to power all those drives at the same time gave us even more room to increase efficiency. We reduced the number of fans per storage node from six to four, reduced the number of power shelves from three to one, and even reduced the number of power supplies in the shelf from seven to five. These server changes then meant that we could reduce the number of Open Rack bus bars from three to one.
    - hinkley 9y ago
      I remember that. It's like a drive carousel but without the arm. I also recall years ago reading about someone who was modifying RAID controllers to spin up the drives one at a time on a cold boot, because peak current draw occurs while spinning up the drives. They were getting brownouts when an entire array spun up at exactly the same time. So they spun them up over a couple of seconds and everything was fine.
zlynx 9y ago
There's other speculation that Glacier is using high density Bluray optical recording with something like 400 GB per disc.
- cptskippy 9y ago
  Isn't optical media a lot less stable than Tape? This seems like a bad idea if you're running an archival service. I use to have a case of CDRs between 1997 and 2004, sometime in 2004 I noticed that many CDRs were becoming unreadable and switched to external HDDs. I kept the case for a while and I think it was 2005 or 2006 that all the disks were empty and I tossed it in the garbage. Around that same time they were starting to phase out LPT ports on PCs and I decided to backup everything I had on reused tapes for an Irwin 40mb Tape drive from 1988 that I acquired sometime in the mid 90s from a salvage shop. I was able to pull everything off the tapes.
  - cat199 9y ago
    > Isn't optical media a lot less stable than Tape? This seems like a bad idea if you're running an archival service. Unless you have some giant warehouse of multiple-copying disk-verifying and re-duplicating robots running around.. which in the case of amazon might actually be the case, and at scale, could save lots on media.. to be clear, I have no personal insight as to how their service works
    - cptskippy 9y ago
      That seems like a lot more trouble than it's worth. From a cost perspective it makes no sense at all. An LTO-6 tape is $25 retail and holds 2.5TB of data, LTO-7 tapes are $90 for 6TB. A 4 Layer BD-R disk is about $15 retail and holds around 100GB of data.
- deleted 9y ago
  [deleted]

rdtsc 9y ago

I am surprised that this hasn't been leaked with how many people work at Amazon. Would expect some anonymous post somewhere "Oh yeah we use X, Y and Z there"

cortesoft 9y ago

Given that you have to request access to your data, then wait a bit of time before you can download lends credence to it being tape based, or at least something similar.

hinkley 9y ago
the power density of these data centers is so high that power and cooling may be your limiting factor. In which case having racks of hard drives where most of them are powered off half of the time would be feasible. But then you have to schedule powering up the right racks for the current set of requests.
- wlesieutre 9y ago
  See Facebook's "Cold Storage" systems for an example of this https://code.facebook.com/posts/1433093613662262 https://code.facebook.com/posts/1433093613662262 > To get the most data into this footprint, we needed high density, but we also needed to remain media-agnostic and low-frills. Using the theme that “less is more,” we started with the Open Vault OCP specification and made changes from there. The biggest change was allowing only one drive per tray to be powered on at a time. In fact, to ensure that a software bug doesn’t power all drives on by mistake and blow fuses in a data center, we updated the firmware in the drive controller to enforce this constraint. The machines could power up with no drives receiving any power whatsoever, leaving our software to then control their duty cycle. > Not having to power all those drives at the same time gave us even more room to increase efficiency. We reduced the number of fans per storage node from six to four, reduced the number of power shelves from three to one, and even reduced the number of power supplies in the shelf from seven to five. These server changes then meant that we could reduce the number of Open Rack bus bars from three to one.
  - hinkley 9y ago
    I remember that. It's like a drive carousel but without the arm. I also recall years ago reading about someone who was modifying RAID controllers to spin up the drives one at a time on a cold boot, because peak current draw occurs while spinning up the drives. They were getting brownouts when an entire array spun up at exactly the same time. So they spun them up over a couple of seconds and everything was fine.

zlynx 9y ago

There's other speculation that Glacier is using high density Bluray optical recording with something like 400 GB per disc.

cptskippy 9y ago
Isn't optical media a lot less stable than Tape? This seems like a bad idea if you're running an archival service. I use to have a case of CDRs between 1997 and 2004, sometime in 2004 I noticed that many CDRs were becoming unreadable and switched to external HDDs. I kept the case for a while and I think it was 2005 or 2006 that all the disks were empty and I tossed it in the garbage. Around that same time they were starting to phase out LPT ports on PCs and I decided to backup everything I had on reused tapes for an Irwin 40mb Tape drive from 1988 that I acquired sometime in the mid 90s from a salvage shop. I was able to pull everything off the tapes.
- cat199 9y ago
  > Isn't optical media a lot less stable than Tape? This seems like a bad idea if you're running an archival service. Unless you have some giant warehouse of multiple-copying disk-verifying and re-duplicating robots running around.. which in the case of amazon might actually be the case, and at scale, could save lots on media.. to be clear, I have no personal insight as to how their service works
  - cptskippy 9y ago
    That seems like a lot more trouble than it's worth. From a cost perspective it makes no sense at all. An LTO-6 tape is $25 retail and holds 2.5TB of data, LTO-7 tapes are $90 for 6TB. A 4 Layer BD-R disk is about $15 retail and holds around 100GB of data.
deleted 9y ago
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