Network speed and IRQ affinity

Written at evening time in English • Tags: , ,

By default many Linux network interface card drivers set their SMP affinity mask to either all zeroes or all ones (“ff” — the length of the mask depends on the number of CPUs on the system). The former results in all queues and interfaces running on CPU ID 0, which can become a performance bottleneck due to insufficient computing power. The latter results in all queues and interfaces being scheduled on multiple CPUs, which can become a performance bottleneck due to increased CPU memory cache misses. (more…)

Uncloudable photos

Written early in the evening in English • Tags: , ,

Since switching to the iCloud Photo Library, the Photos app on my laptop has kept telling me that

  • 1 Item on This Mac Only
  • Unable to Upload 9 Items

To identify the oddball photos, I created the following smart folders respectively:

  • [Photo] [is] [referenced]
  • [Photo] [is] [unable to upload to iCloud Photo Library]

Referenced photos can be consolidated into the library and would then be uploaded to iCloud — mine was a duplicate, so I just deleted it. The photos that could not be uploaded were photos that had been deleted, but somehow a reference had been kept or imported.

References:

Switch back to sysvinit

Written at lunch time in English • Tags: , , ,

If you have already upgraded to jessie and have systemd as init, you can switch back with these commands:

apt-get install -y sysvinit-core
reboot
apt-get purge -y systemd

Running with sysvinit works better on my servers, as daemons have a chance of doing their own graceful shutdown before the network is brought down.

Stay with sysvinit

Written at evening time in English • Tags: , , ,

Before upgrading to jessie, create /etc/apt/preferences.d/use-sysvinit:

Package: systemd-sysv
Pin: release o=Debian
Pin-Priority: -1

See also: How to stay with sysvinit in Debian Jessie by Petter Reinholdtsen

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TIL: Switching a WordPress site to HTTPS will result in mixed content. (more…)

How to fix stuck updates

Written early in the morning in English • Tags: ,

Windows Update has been getting stuck checking for new updates for the past several months. The automatic update somehow manages to complete, at least sometimes, but running a check manually doesn’t complete within a couple of days. It should be more like minutes, shouldn’t it? (more…)