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--- nndocs:initial [2024/07/08 02:11] – [Install extra packages] add mdadm naptastic
+++ nndocs:initial [2024/12/05 18:16] (current) – stub out thing naptastic
@@ Line 3: / Line 3: @@
 Partitioning: The most recent rebuild was shark, for which I took Debian's default EFI setup for the 2TB OS drive. I only changed / to BTRFS instead of ext4. Debian installs itself to a subvolume named @root and makes that subvolume the default, so it's ready for snapshotting backups.
-Remember to add /mnt/snapshots in fstab.
+Add /mnt/snapshots in fstab.
+====Move ~ to a BTRFS subvolume====
+Separate snapshotting the OS from snapshotting your files.
 ====SSH key for root====
@@ Line 12: / Line 15: @@
 ====Reconfigure SSH====
 Configure ssh for a high-numbered port, and not to allow password-based logins. Restart sshd. Verify that 'ssh root@localhost' fails. (You didn't forward your agent, did you?).
+====Backups====
+Create /mnt/snapshots. Create an entry in /etc/fstab the same as for / but with "subvol=/":
+  # / was on /dev/nvme0n1p2 during installation
+  UUID=some-long-string /               btrfs   noatime,nodiratime,subvol=@rootfs 0       0
+  UUID=some-long-string /mnt/snapshots  btrfs   noatime,nodiratime,subvol=/ 0       0
 ====Install Shorewall====
@@ Line 53: / Line 63: @@
    bison flex libssl-dev ncurses-dev libelf-dev
-====Sanitize network interface names====
+====Networking====
+===Device Names===
   ln -s /dev/null /etc/systemd/network/99-default.link
@@ Line 70: / Line 81: @@
   * emoX for ports on the motherboard
   * enX for (multi-)gigabit stand-up cards
+  * ibX for InfiniBand IPoIB devices (these do not need .link files though)
   * mlxX for Mellanox devices in Ethernet mode
-  * ibX for InfiniBand IPoIB devices
-X is 0-indexed. Port 0 on a stand-up card is the farthest from the motherboard. On a motherboard, it's the left-most port if there's more than one port.
+===Port Conventions===
+X is 0-indexed. Port 0 on a stand-up card is the farthest from the motherboard. On a motherboard, it's the left-most port if there's more than one port. I configure ConnectX-3 cards to be InfiniBand on port 0 and Ethernet on port 1, so a system ends up with interfaces named ib0 and mlx1.
-====Network configuration====
+===InfiniBand===
-if I ever figure out how I want to do this, I will certainly let you know!
+  * [[infiniband]]
+  * mst* installer
+  * copy production opensm configuration in case you have take over as SM
+  * (what needs to change here for VMs using virtual functions?)
+Comment out svcrdma in /etc/rdma/modules/rdma.conf or nfs-kernel-server won't start. I'm not sure what's **actually** needed to make NFS/RDMA work.
+===Ethernet configuration===
+Is a total mess right now. I don't know what I'm doing or how I want to do it.
+====Hugepages====
+Useful for databases, PHP, Factorio, and probably other things! Add something like this to /etc/sysctl.conf:
+  vm.nr_hugepages=512
+To make a non-persistent change,
+  sysctl -w vm.nr_hugepages=512
+Make sure your locked memory limit is equal to or greater than the amount of RAM you're reserving for hugepages.
 ====Shell profile====
@@ Line 87: / Line 118: @@
 ====Email====
 lol, not yet
-====InfiniBand====
-[[infiniband]]
-  * mst* installer
-  * copy production opensm configuration in case you have take over as SM
-  * (what needs to change here for VMs using virtual functions?)
-Comment out svcrdma in /etc/rdma/modules/rdma.conf or nfs-kernel-server won't start. I'm not sure what's **actually** needed to make NFS/RDMA work.
 ====Disable TTY screen blanking====