Increase initcwnd on Debian
In case of high latency link, a too small initcwnd could degrade performance, as it may take a while for throughput to increase to its maximum. Increasing initcwnd could mitigateContinue reading
Setting up PTR records (rDNS) for IPv6 address from HE.net’s Tunnel Broker
I used to use Client IPv6 Address for AAAA record of my domain, but the PTR record for that address is pretty weird:
1 2 3 4 | # ping isolated.site PING isolated.site(TB.tunnel.tserv15.lax1.ipv6.he.net (2001:db8:a::2)) 56 data bytes 64 bytes from TB.tunnel.tserv15.lax1.ipv6.he.net (2001:db8:a::2): icmp_seq=1 ttl=63 time=1 ms 64 bytes from TB.tunnel.tserv15.lax1.ipv6.he.net (2001:db8:a::2): icmp_seq=1 ttl=63 time=1 ms |
… and there seems not aContinue reading
WP Super Cache won’t cache pages other than home page
In WP Super Cache’s configuration tab “Advance”, it shows:
1 2 3 4 | Add here strings (not a filename) that forces a page not to be cached. For example... wp-.*\.php index\.php |
And by default (at least for my configuration) WordPress sets Permalink as /index.php/%year%/%monthnum%/%day%/%postname%/. Hence all the posts are “rejected” accordingContinue reading
Specifying kernel image name in uEnv.ini
emmc_autoscript shipped with Armbian hardcoded the kernel image as zImage. That can be convenient for users who do not compile their own kernel. But for those who want to compileContinue reading
Get wireless working on N1
Phicomm N1 uses BCM4345/6. The driver for that chip should come with kernel and needs no extra steps. It’s the firmware that is missing. Hence the firmware should be installedContinue reading
Shorten the lifetime of IPv6 prefixes announced by radvd
This helps when the prefix is dynamic (allocated by ISP dynamically, for example). See also: radvd.conf(5) – Linux man page
1 2 3 4 5 6 7 8 9 | interface br0 { prefix ::/64 { # ... other stuffs AdvValidLifetime 300; # The length of time in seconds that the prefix is valid for the purpose of on-link determination AdvPreferredLifetime 120; # The length of time in seconds that addresses generated from the prefix via stateless address autoconfiguration remain preferred. }; }; |
According to the man page above, AdvValidLifetime less thanContinue reading
Integrate Crayon highlighter with Markdown Editor in WordPress
Two things have to be changed: We have to move language specifier from <code class= to <pre lang=. The newline at the end of code block needs to be removed.Continue reading
samba does not listen on specified address after reboot in Debian
Applying the following patch (copied from the same file in Ubuntu 18.10) to /etc/dhcp/dhclient-enter-hooks.d/samba solved the problem:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | --- ./samba 2019-01-01 00:00:00.000000000 +0800 +++ ./samba.patched 2019-01-01 00:00:00.000000000 +0800 @@ -68,7 +68,18 @@ # reload the samba server # We don't necessarily have the samba package installed. #414841 - [ ! -x /etc/init.d/smbd ] || /usr/sbin/invoke-rc.d smbd reload + if [ -x /etc/init.d/smbd ] + then + if [ -d /run/systemd/system ] + then + if systemctl is-enabled smbd.service --quiet + then + systemctl try-reload-or-restart smbd.service + fi + else + /usr/sbin/invoke-rc.d smbd reload + fi + fi } |
Update /boot/uInitrd automatically after update-initramfs
Put the following to /etc/initramfs/post-update.d/99-uInitrd, and chmod +x to make it executable:
1 2 3 4 5 6 7 | #!/bin/sh set -e # $1 = version, $2 = full path to initrd.img-xxx echo "update-initramfs: Converting to /boot/uInitrd" >&2 temp="/boot/uInitrd-$1" mkimage -A arm64 -O linux -T ramdisk -C gzip -n uInitrd -d $2 $temp 1> /dev/null mv $temp /boot/uInitrd |
This is how update-initramfs -u looks like now:
1 2 3 | # update-initramfs -u update-initramfs: Generating /boot/initrd.img-4.20.0 update-initramfs: Converting to /boot/uInitrd |
Reference: Chapter 8. Package maintainer scripts and hooks.