AlleyPally

Encrypted Btrfs storage setup and maintenance guide

Initial setup with LUKS/dm-crypt

This exemplary initial setup uses two devices /dev/sdb and /dev/sdc but can be applied to any amount of devices by following the steps with additional devices.

Create keyfile:

dd bs=64 count=1 if=/dev/urandom of=/etc/cryptkey iflag=fullblock
chmod 600 /etc/cryptkey

	Segment Concentration Risk
	Nonprofit fundraising is often heavily skewed toward a small number of large donors. Sector-wide data show an extreme Pareto distribution: for example, donors giving over $5,000 represented only about 1.8% of the donor pool but contributed roughly 73% of all donation dollars in early 2023 nonprofitpro.com
	. Conversely, micro donors (<$100) and small donors ($101–$500) made up over 88% of donors but only around 10% of total contributions
	nonprofitpro.com

	nonprofitpro.com
	. This imbalance means many organizations are highly reliant on mid-level and major donors, raising concerns about financial stability if those donors reduce or cease giving. Recent trends have exacerbated this risk: overall donor counts have been declining (especially among small donors), even as total dollars have risen due to big gifts. In 2022, the number of donors dropped over 7%, driven largely by steep declines in small donors, while total fundraising dollars increased ~6%, buoyed by major gifts
	nonprofit

	# Instrument binaries, pgo data to /data/pgo, serial make is important to not confuse the pgo generator
	env CXXFLAGS='-march=native -fprofile-dir=/data/pgo -fprofile-generate=/data/pgo' cmake .. -DCMAKE_BUILD_TYPE=Release
	make -j 1

	# Run instrumented program, generate and write pgo data
	./runIt

	# Use profile data and feed into gcc, correct for threading counter noise, serial make is important to not confuse the pgo generator
	env CXXFLAGS='-march=native -fprofile-dir=/data/pgo -fprofile-use=/data/pgo -fprofile-correction' cmake .. -DCMAKE_BUILD_TYPE=Release
	make -j 1

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	# return code is either 0 (success) or 1 (fail), so you can use it straight-up in logical statements
	coinflip() { return $(($RANDOM%2)); }

	coinflip && echo "heads" \|\| echo "tails"