Just saw on the matrix lightning integration channel that these guys are now bundling matrix (along with already: tor, bitcoind, lnd, c-lightning, mastodon) into their "embassy" node package (which is a packaged raspi as i understand):


#bitcoin #matrix

@waxwing I have two big problems with this project:
- the stupid, restrictive software licence: github.com/Start9Labs/embassy-
- the catastrophic hardware choice of trusting everything on an SDcard

@openoms @waxwing agreed on license.
SD cards specifically designed for constant usage do exist. One big market for them is dash cams, which perform constant writes.

@pete @waxwing
Have to disagree on that, even those kind of SDcards (and I do use only the endurance ones) would only survive a few months running swap or a busy lightning database: github.com/rootzoll/raspiblitz

@openoms @waxwing What brands/sizes have actually failed for you? Have you tried over provisioning?

@openoms @waxwing "Single Level Cell (SLC) are basicly the common SSD-s which are more reliable and fast, but need more power and also more expensive than a USB flash drive."

This is out of date btw. Almost all SSDs on the market right now are multiple level cells.

@openoms @waxwing "Rewrite cycles are respectively around:
80-100k for SLC
8-10k for MLC
3-5k for TLC (not suitable for constant rewrites even for months)"

Also the stats for rewrite cycles are much higher than they actually are. These days modern SSD cells have a rated lifetime of just a few hundred rewrites, not thousands. You see this in total endurance specs, which are typically just a few hundred times the drive capacity.

@pete @waxwing
SSDs really?
Wouldn't be surprised if that would be the specs of cheap SD cards.

@openoms @waxwing Yup: anandtech.com/show/16433/samsu



Those are the first three results on Amazon for "1TB SSD", and they're all TLC flash. Bigger drives are moving to QLD flash, four bits per cell.

SLC-only drives are a very niche product these days. Though it is very common for drives to contain some SLC as a write buffer. That's why drive write speeds often drop after sustained writes - the SLC buffer filled up.


@openoms @waxwing More expensive drives use capacitor backed DRAM for this. If power is removed the drive quickly writes the DRAM contents to flash with the energy in the capacitors.

@openoms @waxwing Many drives can actually dynamically switch between SLC and multiple-bits-per-cell, so as much as 100% of the drive will be used in SLC mode until you fill it up. (By "fill it up", I'm talking about the space that has not been marked as unused with trim)

@pete Thanks for expalanation, that quoted article is indeed outdated, SSDs are not all SLC any more.
Can we say though that the endurance of an SDcard is nowhere close to even a TLC setup of an SSD with SLC or DRAM buffers?
It is just difficult for me to accept that running an operating system and data storage for an intended high use and uptime server can be realisticly based on the cheapest flash storage available.

@pete Agree about redundancy for higher value applications. I am in the process of moving all my self-hosted stuff to a server with a 6 disk ZFS RAID-Z2 and ECC RAM.

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