5 ms·

A server without ECC RAM is not a server, sorry. It's a catastrophe bound to happen.

JKCalhoun 3y ago
Home server though? People use Raspberry Pis for home servers. Speaking of which, guessing the Raspberry Pi 5 with PCIe is going to give the Zimaboard a run for its money.
WJW 3y ago
This makes me think: is there some sort of kernel plugin that ECC-ifies existing memory in software? Similar to how you can implement RAID in software. I even vaguely remember a kernel module (?) that transparently performed in-RAM compression so that you effectively used less memory at the cost of increased CPU usage. Can't find it anymore though.
- smoldesu 3y ago
  > remember a kernel module (?) that transparently performed in-RAM compression Zram? https://docs.kernel.org/admin-guide/blockdev/zram.html https://docs.kernel.org/admin-guide/blockdev/zram.html It won't ECC your memory, but it can handle compression just fine.
- deleted 3y ago
  [deleted]
_bizg 3y ago
Ok, boom
_cenw 3y ago
Just remember, corruption happens outside the memory too.
- nirav72 3y ago
  Yes. Ive seen cheap/bad sata cables cause all kinds of problems for people running home servers.
huhtenberg 3y ago
May not be a "catastrophe", but this is a perfectly valid point. RAM bitflips is one of the sources of bitrot. You may use ZFS, do scrubbing and what not, yet still end up with a corrupted data, because it'd be damaged before it hits the storage.
- dharmab 3y ago
  I've seen a single bitflip cause a 3% error rate on a production service
superq 3y ago
Such a blanket statement is simply not true, sorry, even if ZFS fans like to repeat such mantras. That's like saying that a server without redundant power supplies isn't a server. Google famously ran all of Google search on a million or so cheap desktop-class home-built white boxes (for want of a better term) without dreaming of ECC. It really depends on the workload and what your goals are. There are plenty of places to introduce bitrot aside from RAM, and it's obvious that ECC can't catch all bitrot. If you're not checksumming/hashing, then you won't catch it either, and if you are, then the likelihood of the bitrot matching that hash is basically nil and you'll always detect the bitrot.

Home server though? People use Raspberry Pis for home servers. Speaking of which, guessing the Raspberry Pi 5 with PCIe is going to give the Zimaboard a run for its money.

WJW 3y ago

This makes me think: is there some sort of kernel plugin that ECC-ifies existing memory in software? Similar to how you can implement RAID in software. I even vaguely remember a kernel module (?) that transparently performed in-RAM compression so that you effectively used less memory at the cost of increased CPU usage. Can't find it anymore though.

smoldesu 3y ago
> remember a kernel module (?) that transparently performed in-RAM compression Zram? https://docs.kernel.org/admin-guide/blockdev/zram.html https://docs.kernel.org/admin-guide/blockdev/zram.html It won't ECC your memory, but it can handle compression just fine.
deleted 3y ago
[deleted]

_bizg 3y ago

Ok, boom

_cenw 3y ago

Just remember, corruption happens outside the memory too.

nirav72 3y ago
Yes. Ive seen cheap/bad sata cables cause all kinds of problems for people running home servers.

huhtenberg 3y ago

May not be a "catastrophe", but this is a perfectly valid point. RAM bitflips is one of the sources of bitrot. You may use ZFS, do scrubbing and what not, yet still end up with a corrupted data, because it'd be damaged before it hits the storage.

dharmab 3y ago
I've seen a single bitflip cause a 3% error rate on a production service

superq 3y ago

Such a blanket statement is simply not true, sorry, even if ZFS fans like to repeat such mantras. That's like saying that a server without redundant power supplies isn't a server. Google famously ran all of Google search on a million or so cheap desktop-class home-built white boxes (for want of a better term) without dreaming of ECC. It really depends on the workload and what your goals are. There are plenty of places to introduce bitrot aside from RAM, and it's obvious that ECC can't catch all bitrot. If you're not checksumming/hashing, then you won't catch it either, and if you are, then the likelihood of the bitrot matching that hash is basically nil and you'll always detect the bitrot.