The Curious Engineer

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JRS Systems: the blog

jrs-s.net

technomancy made simple

Linux / UnixStorage / filesystemsDevOps / SRE / infrastructure

’15’20’25
Posts
110 from 10 Feb 2012 to 15 Oct 2026
Posting
now and then (4 in the last year)
Kind
personal blog
Feed
https://jrs-s.net/feed/

2026 4

  1. XigmaNAS using the wrong UFSID
  2. Mounting a UFS2 volume on Ubuntu from .raw
  3. Ubuntu 26.04, KVM, netplan, and NetworkManager
  4. Configuring systemd-resolved to use custom DNS

2025 4

  1. Please STOP trusting email.
  2. Rustdesk Server on Ubuntu 22.04
  3. Salter’s Screwdriver Theory of Latency
  4. TPM errors in Windows 11

2024 1

  1. Windows, KVM, and time zones

2023 1

  1. Adventures in network repair

2022 2

  1. PSA: Cannot open Credentials Manager
  2. 520 byte sectors and Ubuntu

2021 1

  1. WSL2, keychain, /etc/hosts and you

2020 8

  1. When NOTHING else will remove a half-installed .deb package
  2. When static routes on pfSense are ignored
  3. Rebalancing data on ZFS mirrors
  4. Estimating space occupied by multiple ZFS snapshots
  5. Heads up—Let’s Encrypt and Dovecot
  6. Fixing clock drift in Windows VMs under KVM
  7. Why can’t I get to the internet on my new OpnSense install?!
  8. Static routing through VPN servers in OpnSense

2019 8

  1. Fixing Outlook 2016 “Either there is no default mail client…”
  2. Importing WireGuard configs on mobile
  3. zfs set sync=disabled
  4. Continuously updated iostat
  5. Ubuntu 18.04 hung at update-grub 66%
  6. Installing WordPress on Apache the modern way
  7. ZFS sync/async + ZIL/SLOG, explained
  8. About ZFS recordsize

2018 17

  1. Reverse proxy + Let’s Encrypt CertBot
  2. Disable Twitter vibration on Android (8.0 and up)
  3. VLANs with KVM guests on Ubuntu 18.04 / netplan
  4. ZFS write allocation in 0.7.x
  5. ZFS tuning cheat sheet
  6. Routing between wg interfaces with WireGuard
  7. Working VPN-gateway configs for WireGuard
  8. Some testing notes on WireGuard
  9. ZFS does NOT favor lower latency devices. Don’t mix rust disks and SSDs!
  10. sample netplan config for ubuntu 18.04
  11. Wait for network to be configured (no limit)
  12. PSA: new SATA power standard / HGST 10TB drives
  13. Primer: How data is stored on-disk with ZFS
  14. How data gets imbalanced on ZFS
  15. ZFS allocates writes according to free space per vdev, not latency per vdev
  16. Wifi Acronym/Protocol Cheat Sheet
  17. ZVOL vs QCOW2 with KVM

2017 6

  1. Boot rescue for GalliumOS / chrx on Chromebooks
  2. Demonstrating ZFS zpool write distribution
  3. A comprehensive guide to fixing slow SSH logins
  4. Multiple client wifi testing
  5. ZFS clones: Probably not what you really want
  6. Office 2016 for Mac on the Microsoft VLSC (Volume License Service Center) by way of TechSoup

2016 10

  1. Depressing Storage Calculator
  2. Connecting pfSense to a standard OpenVPN Server config
  3. ZFS snapshots and cold storage
  4. Verifying copies
  5. Potentially malicious filenames
  6. PSA: Snapshots are better than ZVOLs
  7. Could not complete SSL handshake, Socket timeout after 10 seconds with Nagios and NSClient++ 0.4x
  8. ZFS: Practicing failures on virtual hardware
  9. Testing copies=n resiliency
  10. zfs: copies=n is not a substitute for device redundancy!

2015 17

  1. FIO cheat sheet
  2. Dual-NIC fanless Celeron 1037u router test – promising!
  3. Emoji on Ubuntu Trusty
  4. Blindrename.pl – a tool to aid blinded analysis in a lab setting
  5. Another KVM storage comparison article
  6. Nagios initial configuration / NSClient++ / check_nt
  7. Blank reports in SimpleInvoices
  8. Reshuffling pool storage on the fly
  9. libguestfs0 and ZFS on Linux in Ubuntu
  10. ZFS compression: yes, you want this
  11. ZFS dedup: tested, found wanting
  12. PSA: don’t buy or trust Lenovo
  13. Exploring copyleft
  14. ZFS: You should use mirror vdevs, not RAIDZ.
  15. Will ZFS and non-ECC RAM kill your data?
  16. Three Step Guide to X11 Forwarding
  17. Avahi killed my server :'(

2014 12

  1. MSE Install fails with 0x8004FF91
  2. The SSLv3 “POODLE” attack in a (large) nutshell
  3. Allowing traceroutes to succeed with iptables
  4. Selectively disabling Windows UAC for individual applications
  5. Fascinating insight into IT and non-profits
  6. OpenVPN on BeagleBone Black
  7. Apache 2.4 / Ubuntu Trusty problems
  8. SELF, Jun 20-22 2014
  9. Using LogMeIn remote control with Linux
  10. Heartbleed SSL vulnerability
  11. Restoring Legacy Boot (Linux Boot) on a Chromebook
  12. btrfs RAID awesomeness

2013 9

  1. Slow performance with dovecot – mysql – roundcube
  2. Block common trojans in SpamAssassin
  3. Benchmarking Windows Guests on KVM:I/O performance
  4. latest signed VirtIO drivers
  5. Windows Server 2012: COA label hatred
  6. Configuring retry duration in Postfix
  7. Windows Server 2012 slow network/SMB/CIFS problem
  8. force directory mode on Samba 3.x
  9. Windows Server 2012 / Windows 8 activation boondoggle

2012 10

  1. Getting SPICE working in Ubuntu 12.04.1-LTS
  2. Cloning an OSX disk using Linux, dd, and parted
  3. Apache 101
  4. Understanding ctime
  5. SouthEast Linux Fest (SELF) 2012
  6. Storing PHP sessions in memcached instead of in files
  7. Enabling core dumps on Apache2.2 on Debian
  8. Opening up SQL server in the Windows Server 2008 firewall
  9. Testing Ubuntu Precise (12.04 LTS beta)
  10. Linux Sysadmin 101