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> We sincerely apologize for the inconvenience that this situation has caused. This type of incident is extremely rare in the web hosting industry. Why are the

by Eikon 7y ago

> We sincerely apologize for the inconvenience that this situation has caused. This type of incident is extremely rare in the web hosting industry. Why are they speaking of the "industry" as a whole when they are to blame? It's even crazier they are not even explaining the source of the data loss and why the "replication systems" didn't help. IHMO they are trying to sweep this event under the carpet. They should instead explain why they should be trusted in the future and why this would not occur again.

briffle 7y ago
In the last few years, I have seen many people confuse replication with backups. People see them as the same thing, but they really aren't. Even with snapshots, if the devices are the same, they might have the same firmware bug, etc.
- deleted 7y ago
  [deleted]
- dv_dt 7y ago
  Just to further explore that a bit, would you say replication adds independent copies for failures of media, while backup adds copies made by independent software against failures of process / software / media.
  - slrz 7y ago
    Replication covers durability (and availability) in face of system or media failure but does nothing whatsoever against software bugs or human error.
  - abtinf 7y ago
    Replication increases risk of data loss when implemented incorrectly, because added resources increase the probability of bit errors. This applies to both replicated disks (RAID) and servers. Replicated servers must use ECC memory as well as checksum blocks and periodically scrub data to ensure integrity (e.g. what ZFS does for you). If they don't then a bit error corrupts the data on all servers, because you have no way of know which copies are pristine or how to piece together pristine parts.
anaphor 7y ago
Replication is not a backup as was already mentioned. A great example of this is when the KDE project almost lost all of their Git repos because they were mirroring a corrupted copy of the data. https://www.phoronix.com/scan.php?page=news_item&px=MTMzNTc https://www.phoronix.com/scan.php?page=news_item&px=MTMzNTc
- Eikon 7y ago
  A backup is a replication of the live dataset, although, usually out of sync to be useful when the main dataset goes bad.
  - y4mi 7y ago
    You might want to read the Wikipedia definition, because you're technically mistaken. https://en.m.wikipedia.org/wiki/Backup https://en.m.wikipedia.org/wiki/Backup
    - Eikon 7y ago
      I'm not, you can't do backup without replicating data, hence, if you do backup, you are doing replication.
      - y4mi 7y ago
        It can be, it just doesn't have to be Let's say a typical admin of a small shop wants to backup his postgres database. The first thing he'll use is probably pg_dumpall which he'll output to a storage. No replication involved. The backup is just a bunch of sql statements to recover the last known state of the database. It's a different kind of format however, which -by definition- isn't a replica anymore. (And this process has several caveat's-one of which is that it can produce unusable dumps in some rare cases and isn't complete. users, triggers etc aren't dumped iirc.. could be wrong there)
        Eikon 7y ago
        > No replication involved. The backup is just a bunch of sql statements to recover the last known state of the database. You probably should look up the definition of “replication”.
sansnomme 7y ago
Replication is explicitly designed to correct issues associated with bitrot and add redundancy.
celticmusic 7y ago
yeah, I worked for several years at a hosting provider, and I can tell you for a fact that this wouldn't have happened there. They're 100% virtualized and keep backups of all those machines. In addition, you can purchase a package so that YOUR backups are automatically backed up to 2 different datacenters. Between the two of those solutions, there would be a way forward. I don't really know what Gandi is so I can't speak to them directly, but this is a solvable problem.
deleted 7y ago
[deleted]

by Eikon 7y ago

briffle 7y ago

In the last few years, I have seen many people confuse replication with backups. People see them as the same thing, but they really aren't. Even with snapshots, if the devices are the same, they might have the same firmware bug, etc.

deleted 7y ago
[deleted]
dv_dt 7y ago
Just to further explore that a bit, would you say replication adds independent copies for failures of media, while backup adds copies made by independent software against failures of process / software / media.
- slrz 7y ago
  Replication covers durability (and availability) in face of system or media failure but does nothing whatsoever against software bugs or human error.
- abtinf 7y ago
  Replication increases risk of data loss when implemented incorrectly, because added resources increase the probability of bit errors. This applies to both replicated disks (RAID) and servers. Replicated servers must use ECC memory as well as checksum blocks and periodically scrub data to ensure integrity (e.g. what ZFS does for you). If they don't then a bit error corrupts the data on all servers, because you have no way of know which copies are pristine or how to piece together pristine parts.

anaphor 7y ago

Replication is not a backup as was already mentioned. A great example of this is when the KDE project almost lost all of their Git repos because they were mirroring a corrupted copy of the data. https://www.phoronix.com/scan.php?page=news_item&px=MTMzNTc https://www.phoronix.com/scan.php?page=news_item&px=MTMzNTc

Eikon 7y ago
A backup is a replication of the live dataset, although, usually out of sync to be useful when the main dataset goes bad.
- y4mi 7y ago
  You might want to read the Wikipedia definition, because you're technically mistaken. https://en.m.wikipedia.org/wiki/Backup https://en.m.wikipedia.org/wiki/Backup
  - Eikon 7y ago
    I'm not, you can't do backup without replicating data, hence, if you do backup, you are doing replication.
    - y4mi 7y ago
      It can be, it just doesn't have to be Let's say a typical admin of a small shop wants to backup his postgres database. The first thing he'll use is probably pg_dumpall which he'll output to a storage. No replication involved. The backup is just a bunch of sql statements to recover the last known state of the database. It's a different kind of format however, which -by definition- isn't a replica anymore. (And this process has several caveat's-one of which is that it can produce unusable dumps in some rare cases and isn't complete. users, triggers etc aren't dumped iirc.. could be wrong there)
      - Eikon 7y ago
        > No replication involved. The backup is just a bunch of sql statements to recover the last known state of the database. You probably should look up the definition of “replication”.

sansnomme 7y ago

Replication is explicitly designed to correct issues associated with bitrot and add redundancy.

celticmusic 7y ago

yeah, I worked for several years at a hosting provider, and I can tell you for a fact that this wouldn't have happened there. They're 100% virtualized and keep backups of all those machines. In addition, you can purchase a package so that YOUR backups are automatically backed up to 2 different datacenters. Between the two of those solutions, there would be a way forward. I don't really know what Gandi is so I can't speak to them directly, but this is a solvable problem.

deleted 7y ago

[deleted]