I was looking into htop
and the only process having > 0.0% CPU (apart from htop itself) was /usr/lib/udisks/udisks-daemon
.
So the questions are: What is this service? Do I need it? (Or when do I need it?) Why is it accessing the drives?
udisks
:The udisks daemon serves as an interface to system block devices, implemented via D-Bus. It handles operations such as querying, mounting, unmounting, formatting, or detaching storage devices such as hard disks or USB thumb drives.
This package also provides the udisks utility, which can be used to trigger these operations from the command line (if permitted by PolicyKit). External tools such as hdparm are used if available to implement extra operations, such as configuring disk spindown times.
Creating or modifying file systems such as XFS, RAID, or LUKS encryption requires that the corresponding mkfs.* and admin tools are installed, such as dosfstools and mtools for VFAT, xfsprogs for XFS, or cryptsetup for LUKS.
Do I need it?
This should be considered an essential package by almost everyone. The only time I would consider removing it is if I had a simple /dev/sdX
CLI install on a machine where there was no need for udev
-- i.e., the hardware never changes (which in practice almost always means a virtual machine, a VPS or a very very old machine).
Here is another take on your second question about whether you need it: It depends on what your objectives are. If you want to learn about how your system works under the hood, you definitely do not need any udisks
daemon. Not even on Ubuntu.
I am speaking out of my own experience here. The world needs more people who are curious about what is going on under the hood. See my code on GitHub for reference.
You should also find a command line tool called udisksctl
. With this tool you can see details what the daemon is doing in the background.
Show Status:
$ udisksctl status
MODEL REVISION SERIAL DEVICE
--------------------------------------------------------------------------
Micron xxxxxxxxx M0MA020 xxxxxxxxxxxxx sda
Generic STORAGE DEVICE 1454 Generic_STORAGE_DEVICE-0:0 sdb sdc
TOSHIBA xxxxxxxxx 0100 xxxxxxxxxxxxx sdd
Monitor Progress:
$ udisksctl monitor
Monitoring the udisks daemon. Press Ctrl+C to exit.
10:48:03.241: The udisks-daemon is running (name-owner :1.8).
10:48:03.404: /org/freedesktop/UDisks2/jobs/2: org.freedesktop.UDisks2.Job: Properties Changed
ExpectedEndTime: 1699178852131486
Rate: 28536135
Progress: 0.58324379569695217