docs(notes): expand storage, btrfs, linux, and ssh notes
btrfs.md:
- Add device scan (no-arg form) and device stats --reset / -z
- Add read-only mount, remount with performance/default options
- Add Degraded Mount and Missing Device Removal subsection
- Add stdbuf + zstd backgrounded defrag with log output
- Add RAID1 balance conversion
- Add ionice for scrub, watch scrub+device stats, watch scrub+temperatures
- Add Recovery → Filesystem Check (btrfs check, --force)
- Add Recovery → Diagnosis (journal by date, dmesg btrfs filter)
linux.md:
- Add CPU info commands (lscpu, /proc/cpuinfo, core count)
- Add GPU info (lspci | grep vga) and CPU scaling driver
- Add mount --bind and chroot with pseudo-fs setup
- Add update-initramfs -k all and -c -k $(uname -r) variants
- Add NFS section (showmount, exportfs)
- Add Network Diagnostics section (curl timing, high-freq ping, jumbo frame ping)
- Add journal date filtering and microcode grep to Diagnosis
ssh.md:
- Add Placeholders section
- Replace all hardcoded usernames, hostnames, IPs, and key paths with placeholders
- Add Skip Host Key Verification section (StrictHostKeyChecking, UserKnownHostsFile)
storage.md:
- Add lsblk -e 7 to exclude loop devices
- Add blkid <partition> variant
- Add cat /proc/mounts grep
- Add SMART filtered greps (Reallocated, Pending, UDMA_CRC, Load_Cycle_Count)
- Add drive temperature one-liner and watch loop
- Add Hardware Monitoring section (lm-sensors, sensors-detect, sensors)
- Add Kernel Messages section (dmesg tail, err/warn, -T, nvme, ata/scsi, I/O, ATA port mapping)
- Add strings on raw device to Hex Dump
Fabrice Quenneville
89e4bd519a