Skip to content

Latest commit

 

History

History
161 lines (112 loc) · 3.17 KB

miscelaneous_sysadmin.md

File metadata and controls

161 lines (112 loc) · 3.17 KB

Miscelaneous sysadmin notes

Scratchpad, tips related to system administrator tasks or configuration of certain services running on free-unraid OS.

OpenWRT

Calculating DHCP scope settings

ipcalc.sh network-ip mask-or-prefix start limit

https://forum.openwrt.org/t/dhcp-range-configuration/67452/7

Ubuntu

Newer ZFS repo

https://launchpad.net/~jonathonf/+archive/ubuntu/zfs

sudo add-apt-repository ppa:jonathonf/zfs
sudo apt update

Plex Media Server

Keeping plex-media-server package up-to-date

https://github.com/mrworf/plexupdate

Limit ZFS Memory usage to 3GB on NAS VM

Dynamic during runtime.

echo "$[3 * 1024*1024*1024]" >/sys/module/zfs/parameters/zfs_arc_max

Permanent, add/create /etc/modprobe.d/zfs.conf

options zfs zfs_arc_max=3221225472

Samba

Newer builds for ubuntu

https://launchpad.net/~linux-schools/+archive/ubuntu/samba-latest

Docker

Update all containers

docker run -v /var/run/docker.sock:/var/run/docker.sock containrrr/watchtower --run-once

NTP

Ensure timesync. File: /etc/systemd/timesyncd.conf

[Time]
NTP=time.google.com time1.google.com time2.google.com time3.google.com
FallbackNTP=0.pool.ntp.org 1.pool.ntp.org 0.debian.pool.ntp.org

Restart systemd-timesyncd.service - done.

Folder listings timestamp include year (ls)

Add to .bashrc file

export TIME_STYLE=long-iso

Btrfs

Change the partition label

If system is mounted (live change)

btrfs filesystem label <mountpoint> <newlabel>

If unmounted

btrfs filesystem label <device> <newlabel>

Make necessary updates in /etc/fstab

NFS

Check if kernel supports which NFS versions https://wiki.debian.org/NFSServerSetup

grep NFSD /boot/config-`uname -r`

check enabled versions

cat /proc/fs/nfsd/versions

Make sure to tweak these configuration files on the server to force NFS v4 always.

/etc/nfs.conf
/etc/default/nfs-common
/etc/default/nfs-kernel-server

The easy way to enable NFS v4.2

# nfsconf --set nfsd vers4.2 y
root@nas:/home/gfm# nfsconf --get nfsd vers4.2
y
# cat /etc/nfs.conf

Important section

 vers2=n
 vers3=n
 vers4=n
 vers4.0=n
 vers4.1=y
 vers4.2=y

If rpc-statd.service complains after disabling V2 V3 NFS. Mask it.

systemctl mask rpc-statd.service

Check dependencies and its service status

systemctl list-dependencies nfs-kernel-server

Mounting NFSv4 on client

When faced with error mount.nfs4: mounting 192.168.1.54:/mnt/cached failed, reason given by server: No such file or directory

The hint was fsid=0 from https://askubuntu.com/questions/35077/cannot-mount-nfs4-share-no-such-file-or-directory and the path we use to mount.

In NFSv3 the old mount command was (when share had fsid=0 in its exports config):

mount -t nfs 192.168.1.54:/mnt/cached /mnt/derp/

NFSv4 format, fsid has special meaning to the path.

mount.nfs4 -o vers=4.2 192.168.1.54:/ /mnt/derp/

More on this: https://unix.stackexchange.com/questions/427597/implications-of-using-nfsv4-fsid-0-and-exporting-the-nfs-root-to-entire-lan-or

You can avoid this altogether by simply using fsid=1 or anything other than zero.