  The phase 1 upgrade of the CMS pixel detector has been designed to maintain
the tracking performance at instantaneous luminosities of $2 \times 10^{34}
\mathrm{~cm}^{-2} \mathrm{~s}^{-1}$. Both barrel and endcap disk systems now
feature one extra layer (4 barrel layers and 3 endcap disks), and a digital
readout that provides a large enough bandwidth to read out its 124M pixel
channels (87.7 percent more pixels compared to the previous system). The
backend control and readout systems have been upgraded accordingly from
VME-based to micro-TCA-based ones. The detector is now also equipped with a
bi-phase CO$_2$ cooling system that reduces the material budget in the tracking
region. The detector has been installed inside CMS at the start of 2017 and is
now taking data. These proceedings discuss experiences in the commissioning and
operation of the CMS phase 1 pixel detector. The first results from the CMS
phase 1 pixel detector with this year's LHC proton-proton collision data are
presented. The new pixel detector outperforms the previous one in terms of hit
resolution, tracking, and vertex resolution.
