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I would love to have this. Old disks are no problem. They will most likely continue to run fine until they no longer are worth it due to either insane electrici

by olavgg 4y ago

I would love to have this. Old disks are no problem. They will most likely continue to run fine until they no longer are worth it due to either insane electricity prices or 50TB hard drives becomes available for a bargain. My backup server is still running almost 17-18 years old 500GB hard drives. They will be retired soon though, as they consume too much power and lack spindown when not in use.

throw0101c 4y ago
> […] and lack spindown when not in use. I was under the impression that constant on-off was what put the most wear on a drive, and that if it is constantly on it would last longer.
- fluoridation 4y ago
  Yep. In a previous iteration of my file server I killed a WD green drive in about two years because I unwittingly left the head park feature on. It was parking after 8 seconds of inactivity, and in two years it had accumulated like 2.5 million parks.
- olavgg 4y ago
  Not really. With minimum 50000 cycles, you can spin up and down 28 times every day for 5 years. It may not sound a lot, but in reality it is. I have my NAS set to spindown after 15 minutes idle time and have on average around 1000 cycles every year.
gjulianm 4y ago
I think there's a difference between the wear and tear in a personal backup server and in a Netflix cache server. We manage several storage servers which see intensive usage, and usually at around 5 years we start to see disk failures.
- dachryn 4y ago
  its fair to assume netflix is mostly doing reads and not writes, and also fairly sequential. Thats very good for longevity of the disks
  - michaelt 4y ago
    True - but presumably they've been spinning and doing seeks pretty much 24/7. It's not like backblaze/coldline where the drives are practically powered down most of the time. And of course, 36x the drives means 36x the drive failures - and even if you avoid losing data, you've still got the chore of swapping each failed drive.
    - dijit 4y ago
      Constantly spinning is better for the motor than starting and stopping.
    - Maursault 4y ago
      > And of course, 36x the drives means 36x the drive failures I think you must mean 36x the chance of drive failure. Drive failure probability per year is published at around 1% though practically as high as 10%. 36 drives means there's somewhere between a 30.35% (1 - 0.99^36) and 97.7% (1 - 0.9^36) chance per year of a single drive failing.
  - justsomehnguy 4y ago
    > and also fairly sequential ... No. When you hit hundreds of concurrent operations there is no such thing as sequential. Also there is no need for sequential reads because a stripe of 7-15 disks would give you much more than streaming bitrate needs.
- olavgg 4y ago
  I think that is a good point, however MTBF is usually a lot higher on enterprise grade hard drives. My hard drives are consumer grade.
- Hamuko 4y ago
  >We manage several storage servers which see intensive usage, and usually at around 5 years we start to see disk failures. Which begs the question of how old the drives actually are. If intensive usage would result in lots of disk failures after 5 years, then a 9-year-old server would surely have a bunch of new(er) disks inside it? Or do they just reduce the amount of cache space they have with every failure?
  - js2 4y ago
    The latter. The case design clearly doesn’t lend itself to replacing drives. https://old.reddit.com/r/homelab/comments/ydollm/so_i_got_a_netflix_cache_server/ittpppw/ https://old.reddit.com/r/homelab/comments/ydollm/so_i_got_a_...
  - gjulianm 4y ago
    Of course, the timing depends on the usage pattern. In our case we write a lot to the disks, which means they fail faster. Time to failure also depends on manufacturer, batch, server conditions... But in general I wouldn't trust too much that have been continuously running under a significant load (I don't think a Netflix cache server had a lot of idle time) for so many years.
aasasd 4y ago
For some reason the make and model of those disks is absent from your comment, must've been lost in the wires.
- olavgg 4y ago
  They are a mix of Samsung, WD and Seagate. 2 of them are PATA, while the rest is SATA
dylan604 4y ago
>or 50TB hard drives becomes available for a bargain. Maybe my old age is showing, but this just frightens me to no end. 1 50TB failure, and you've lost 50TB. Build an array of smaller drives to get to 50TB, and much less catastrophe if 1 drive dies.
- NicoJuicy 4y ago
  Maintenance costs money too. What if you have to replace 3 times more often because of the smaller drives?
  - dylan604 4y ago
    if it costs some $ to be able to recover is still better than not being able to recover at all because the single point of failure fails

by olavgg 4y ago

throw0101c 4y ago

> […] and lack spindown when not in use. I was under the impression that constant on-off was what put the most wear on a drive, and that if it is constantly on it would last longer.

fluoridation 4y ago
Yep. In a previous iteration of my file server I killed a WD green drive in about two years because I unwittingly left the head park feature on. It was parking after 8 seconds of inactivity, and in two years it had accumulated like 2.5 million parks.
olavgg 4y ago
Not really. With minimum 50000 cycles, you can spin up and down 28 times every day for 5 years. It may not sound a lot, but in reality it is. I have my NAS set to spindown after 15 minutes idle time and have on average around 1000 cycles every year.

gjulianm 4y ago

I think there's a difference between the wear and tear in a personal backup server and in a Netflix cache server. We manage several storage servers which see intensive usage, and usually at around 5 years we start to see disk failures.

dachryn 4y ago
its fair to assume netflix is mostly doing reads and not writes, and also fairly sequential. Thats very good for longevity of the disks
- michaelt 4y ago
  True - but presumably they've been spinning and doing seeks pretty much 24/7. It's not like backblaze/coldline where the drives are practically powered down most of the time. And of course, 36x the drives means 36x the drive failures - and even if you avoid losing data, you've still got the chore of swapping each failed drive.
  - dijit 4y ago
    Constantly spinning is better for the motor than starting and stopping.
  - Maursault 4y ago
    > And of course, 36x the drives means 36x the drive failures I think you must mean 36x the chance of drive failure. Drive failure probability per year is published at around 1% though practically as high as 10%. 36 drives means there's somewhere between a 30.35% (1 - 0.99^36) and 97.7% (1 - 0.9^36) chance per year of a single drive failing.
- justsomehnguy 4y ago
  > and also fairly sequential ... No. When you hit hundreds of concurrent operations there is no such thing as sequential. Also there is no need for sequential reads because a stripe of 7-15 disks would give you much more than streaming bitrate needs.
olavgg 4y ago
I think that is a good point, however MTBF is usually a lot higher on enterprise grade hard drives. My hard drives are consumer grade.
Hamuko 4y ago
>We manage several storage servers which see intensive usage, and usually at around 5 years we start to see disk failures. Which begs the question of how old the drives actually are. If intensive usage would result in lots of disk failures after 5 years, then a 9-year-old server would surely have a bunch of new(er) disks inside it? Or do they just reduce the amount of cache space they have with every failure?
- js2 4y ago
  The latter. The case design clearly doesn’t lend itself to replacing drives. https://old.reddit.com/r/homelab/comments/ydollm/so_i_got_a_netflix_cache_server/ittpppw/ https://old.reddit.com/r/homelab/comments/ydollm/so_i_got_a_...
- gjulianm 4y ago
  Of course, the timing depends on the usage pattern. In our case we write a lot to the disks, which means they fail faster. Time to failure also depends on manufacturer, batch, server conditions... But in general I wouldn't trust too much that have been continuously running under a significant load (I don't think a Netflix cache server had a lot of idle time) for so many years.

aasasd 4y ago

For some reason the make and model of those disks is absent from your comment, must've been lost in the wires.

olavgg 4y ago
They are a mix of Samsung, WD and Seagate. 2 of them are PATA, while the rest is SATA

dylan604 4y ago

>or 50TB hard drives becomes available for a bargain. Maybe my old age is showing, but this just frightens me to no end. 1 50TB failure, and you've lost 50TB. Build an array of smaller drives to get to 50TB, and much less catastrophe if 1 drive dies.

NicoJuicy 4y ago
Maintenance costs money too. What if you have to replace 3 times more often because of the smaller drives?
- dylan604 4y ago
  if it costs some $ to be able to recover is still better than not being able to recover at all because the single point of failure fails