8 ms·

> I'll just be doing RAID and ext4 Why do you need/want RAID ? RAID is for availability, but is your data really that important that you cannot wait for a re

> I'll just be doing RAID and ext4 Why do you need/want RAID ? RAID is for availability, but is your data really that important that you cannot wait for a restore ? Most people would be much better off using that 1..N parity drives as versioned backups instead of running RAID. I've run NAS boxes for years, but these days i'm only using single drives. My setup these days consists of laptops that synchronizes data (encrypted) to the cloud, and a small ARM machine that synchronizes cloud contents locally, and makes a versioned backup to a single drive as well as a versioned cloud backup. As for cost, it's cheaper (for me) to store my data in the cloud, than the cost of electricity required to run my NAS.

eternityforest 3y ago
I was going to do RAID for disk failure tolerance, either with a consumer NAS box, or a disk enclosure that does hardware RAID, and something very low power like a Zero 2 W. Isn't RAID parity slightly more space efficient than versioned backups? Or is there a better way to do redundancy that doesn't involve just replicating entire files to multiple disks? Or some kind of automated manager that puts each individual file on N different disks out of M? I mostly do embedded so reliable data storage isn't generally something I deal with, we usually leave that to the cloud or to the user, and I'm not quite familiar with what's out there.
- 8fingerlouie 3y ago
  >Isn't RAID parity slightly more space efficient than versioned backups? It depends on your storage array. The more drives, the more space efficient RAID becomes, but RAID is still only a single copy of your data. >Or is there a better way to do redundancy that doesn't involve just replicating entire files to multiple disks Most of the industry is using erasure coding these days (https://blog.min.io/erasure-coding/ https://blog.min.io/erasure-coding/) which allows for spreading your parity and data across multiple sites. Erasure coding usually runs a layer above the filesystem, as opposed to RAID which typically runs below the filesystem (Snapraid, Mergerfs and others excluded). My personal "backup vault" is a Raspberry Pi 4 with a single 4TB external drive attached. The RPi runs Minio, and all backups are done through the S3 interface or SFTP/SMB. It is not the fastest box in the world, but it backs up (incremental) ~2TB in 30 minutes, which is "fast enough". It consumes on average 4W, which means even with worst case electricity prices of €1/kWh (which we saw last winter), it costs less than €3/month. For comparison, my NAS consumed around 50W, and at €1/kWh, that would cost €37/month in electricity alone, and then you need to add the cost of the actual hardware itself. I switched off the NAS, and purchased ~10TB of cloud storage (main storage and backup storage at two different locations) for €20/month, and keep sensitive stuff encrypted with Cryptomator.
  - tremon 3y ago
    but RAID is still only a single copy of your data Btrfs has 3-copy and 4-copy RAID1 (profiles raid1c3 and raid1c4), doesn't ZFS have something similar?
    - 8fingerlouie 3y ago
      ZFS has RAIDZ1, RAIDZ2, RAIDz3 and Ditto blocks, which do much the same thing, although a bit differently. My point was that even if you have 4 copies of your data, you still only have a single machine where your data is stored, and you're essentially just one flood/lightning strike/house fire/burglary away from all of it being gone. Or one bad power supply away from 4 dead drives. With versioned backups, you have higher latency on restoring data in case a disk dies, but your data is also safer. As i initially stated, RAID is for availability. It is great for making sure that data is available 24/7, but that is rarely what the average home user needs. Most home users access their data infrequently, and would be perfectly fine waiting a couple of hours while restoring data from a backup.
redeeman 3y ago
> As for cost, it's cheaper (for me) to store my data in the cloud, than the cost of electricity required to run my NAS. how much data are we talking about?
- 8fingerlouie 3y ago
  I have around 10TB data stored in the cloud, including backups. Total cloud bill is around €23/month (recent price increase included). There is a turning point somewhere after 15TB where the cloud becomes a lot more expensive than local storage, but at 10TB it’s hard to do in a reliable manner locally. And it doesn’t really matter how you do it. If you’re the DIY type, and buy a second hand server, or a small machine, or just run out and buy the latest Synology box, you’re still paying more for storing <15TB at home in RAID. One will be more expensive in electricity, the other in purchase price.
neuromanser 3y ago
I had a FreeBSD box with data on a gmirror of two disks for a decade. Twice in that period I had one of the disks die. Each time I would buy a new disk, add it into the array, and go on with next to no effort. As for cost, I would have had the box anyway, so it wasn't like i was paying for an extra system, just an extra disk. Cloud backup would have cost me several orders of magnitude more, this was a media library of hundreds of gigabytes, eventually low terabytes. Plus all the complexity of working backup/restore procedures.
- 8fingerlouie 3y ago
  And how much power does that box consume ? The average price of power during a year here is around €0.45/year, so a box drawing 50W (not unlikely with a decade old processor and two disks) will use 438 kWh during a year, meaning it would cost €197/year to keep it powered. Add to that the ~€150 x 2 for new drives, and you end up with €227/year, or €19/month. But of course, if you, as you stated, had the box running anyway, the math works out differently as you're essentially splitting the cost with whatever purpose the box already fulfills.
  - neuromanser 3y ago
    The system started its existence on a VIA EPIA board with a sata controller pci card, later upgraded to an Intel Atom-based Supermicro board. The Atom was 20W TDP iirc, the VIA less than that. The system was mostly idle.

eternityforest 3y ago

I was going to do RAID for disk failure tolerance, either with a consumer NAS box, or a disk enclosure that does hardware RAID, and something very low power like a Zero 2 W. Isn't RAID parity slightly more space efficient than versioned backups? Or is there a better way to do redundancy that doesn't involve just replicating entire files to multiple disks? Or some kind of automated manager that puts each individual file on N different disks out of M? I mostly do embedded so reliable data storage isn't generally something I deal with, we usually leave that to the cloud or to the user, and I'm not quite familiar with what's out there.

8fingerlouie 3y ago
>Isn't RAID parity slightly more space efficient than versioned backups? It depends on your storage array. The more drives, the more space efficient RAID becomes, but RAID is still only a single copy of your data. >Or is there a better way to do redundancy that doesn't involve just replicating entire files to multiple disks Most of the industry is using erasure coding these days (https://blog.min.io/erasure-coding/ https://blog.min.io/erasure-coding/) which allows for spreading your parity and data across multiple sites. Erasure coding usually runs a layer above the filesystem, as opposed to RAID which typically runs below the filesystem (Snapraid, Mergerfs and others excluded). My personal "backup vault" is a Raspberry Pi 4 with a single 4TB external drive attached. The RPi runs Minio, and all backups are done through the S3 interface or SFTP/SMB. It is not the fastest box in the world, but it backs up (incremental) ~2TB in 30 minutes, which is "fast enough". It consumes on average 4W, which means even with worst case electricity prices of €1/kWh (which we saw last winter), it costs less than €3/month. For comparison, my NAS consumed around 50W, and at €1/kWh, that would cost €37/month in electricity alone, and then you need to add the cost of the actual hardware itself. I switched off the NAS, and purchased ~10TB of cloud storage (main storage and backup storage at two different locations) for €20/month, and keep sensitive stuff encrypted with Cryptomator.
- tremon 3y ago
  but RAID is still only a single copy of your data Btrfs has 3-copy and 4-copy RAID1 (profiles raid1c3 and raid1c4), doesn't ZFS have something similar?
  - 8fingerlouie 3y ago
    ZFS has RAIDZ1, RAIDZ2, RAIDz3 and Ditto blocks, which do much the same thing, although a bit differently. My point was that even if you have 4 copies of your data, you still only have a single machine where your data is stored, and you're essentially just one flood/lightning strike/house fire/burglary away from all of it being gone. Or one bad power supply away from 4 dead drives. With versioned backups, you have higher latency on restoring data in case a disk dies, but your data is also safer. As i initially stated, RAID is for availability. It is great for making sure that data is available 24/7, but that is rarely what the average home user needs. Most home users access their data infrequently, and would be perfectly fine waiting a couple of hours while restoring data from a backup.

redeeman 3y ago

> As for cost, it's cheaper (for me) to store my data in the cloud, than the cost of electricity required to run my NAS. how much data are we talking about?

8fingerlouie 3y ago
I have around 10TB data stored in the cloud, including backups. Total cloud bill is around €23/month (recent price increase included). There is a turning point somewhere after 15TB where the cloud becomes a lot more expensive than local storage, but at 10TB it’s hard to do in a reliable manner locally. And it doesn’t really matter how you do it. If you’re the DIY type, and buy a second hand server, or a small machine, or just run out and buy the latest Synology box, you’re still paying more for storing <15TB at home in RAID. One will be more expensive in electricity, the other in purchase price.

neuromanser 3y ago

I had a FreeBSD box with data on a gmirror of two disks for a decade. Twice in that period I had one of the disks die. Each time I would buy a new disk, add it into the array, and go on with next to no effort. As for cost, I would have had the box anyway, so it wasn't like i was paying for an extra system, just an extra disk. Cloud backup would have cost me several orders of magnitude more, this was a media library of hundreds of gigabytes, eventually low terabytes. Plus all the complexity of working backup/restore procedures.

8fingerlouie 3y ago
And how much power does that box consume ? The average price of power during a year here is around €0.45/year, so a box drawing 50W (not unlikely with a decade old processor and two disks) will use 438 kWh during a year, meaning it would cost €197/year to keep it powered. Add to that the ~€150 x 2 for new drives, and you end up with €227/year, or €19/month. But of course, if you, as you stated, had the box running anyway, the math works out differently as you're essentially splitting the cost with whatever purpose the box already fulfills.
- neuromanser 3y ago
  The system started its existence on a VIA EPIA board with a sata controller pci card, later upgraded to an Intel Atom-based Supermicro board. The Atom was 20W TDP iirc, the VIA less than that. The system was mostly idle.