Sam Hooke

These are rough notes from whatever I was working on, interested in or thinking about at the time. They vary greatly in quality and length, but prove useful to me, and hopefully to you too!

Freeing up disk space on Arch Linux

Visualising what is using up disk space

To visualise what is taking up disk space I use qdirstat:

$ sudo pacman -S qdirstat
$ qdirstat

Launching it opens a GUI which can be used to see what is hogging disk space.

The pacman cache is taking up a significant chunk.

Clearing up the pacman cache

To free up space from the pacman cache, use the paccache package. It used to be included by default, but is now included in the pacman-contrib package:

$ sudo pacman -S pacman-contrib

Using the -r option will by default delete all but the last 3 most recent versions of previously cached packages:

$ sudo paccache -r
==> finished: 104 packages removed (disk space saved: 555.24 MiB)

Use k to specify how many most recent versions to keep, for example to keep only the most recently cached version:

$ sudo paccache -rk1
==> finished: 612 packages removed (disk space saved: 2.45 GiB)

Further, use the u option to target only uninstalled packages in the cache. For example, to delete all cached copies of all uninstalled packages:

$ paccache -ruk0
==> finished: 58 packages removed (disk space saved: 89.48 MiB)

You could use -rk0 to delete all cached copies of all uninstalled and installed packages, but this is advised against in case you want to downgrade or re-install without downloading. However it may be helpful if all other attempts to free up disk space have not been sufficient.

Clearing up orphaned packages

To delete orphaned packages:

$ pacman -Rns $(pacman -Qtdq)

Further commands for viewing disk usage

To view which disks are present:

$ sudo fdisk -l
Disk /dev/sda: 119.2 GiB, 128035676160 bytes, 250069680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 9F94F053-B3CD-4ADF-92A1-9272701DCB5B

Device        Start       End   Sectors  Size Type
/dev/sda1      2048   1050623   1048576  512M EFI System
/dev/sda2   1050624  42991615  41940992   20G Linux filesystem
/dev/sda3  42991616  51380223   8388608    4G Linux swap
/dev/sda4  51380224 250068991 198688768 94.8G Linux filesystem


Disk /dev/loop0: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop1: 2 GiB, 2147483648 bytes, 4194304 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/docker-8:2-658581-pool: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 65536 bytes / 65536 bytes

To view what file systems are currently mounted:

$ findmnt
TARGET                                SOURCE      FSTYPE      OPTIONS
/                                     /dev/sda2   ext4        rw,relatime,data=ordered
├─/proc                               proc        proc        rw,nosuid,nodev,noexec,relatime
│ └─/proc/sys/fs/binfmt_misc          systemd-1   autofs      rw,relatime,fd=27,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=12637
│   └─/proc/sys/fs/binfmt_misc        binfmt_misc binfmt_misc rw,relatime
├─/sys                                sys         sysfs       rw,nosuid,nodev,noexec,relatime
│ ├─/sys/firmware/efi/efivars         efivarfs    efivarfs    rw,nosuid,nodev,noexec,relatime
│ ├─/sys/kernel/security              securityfs  securityfs  rw,nosuid,nodev,noexec,relatime
│ ├─/sys/fs/cgroup                    tmpfs       tmpfs       ro,nosuid,nodev,noexec,mode=755
│ │ ├─/sys/fs/cgroup/unified          cgroup2     cgroup2     rw,nosuid,nodev,noexec,relatime,nsdelegate
│ │ ├─/sys/fs/cgroup/systemd          cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,xattr,name=systemd
│ │ ├─/sys/fs/cgroup/blkio            cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,blkio
│ │ ├─/sys/fs/cgroup/pids             cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,pids
│ │ ├─/sys/fs/cgroup/cpu,cpuacct      cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,cpu,cpuacct
│ │ ├─/sys/fs/cgroup/net_cls,net_prio cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,net_cls,net_prio
│ │ ├─/sys/fs/cgroup/cpuset           cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,cpuset
│ │ ├─/sys/fs/cgroup/perf_event       cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,perf_event
│ │ ├─/sys/fs/cgroup/memory           cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,memory
│ │ ├─/sys/fs/cgroup/rdma             cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,rdma
│ │ ├─/sys/fs/cgroup/freezer          cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,freezer
│ │ ├─/sys/fs/cgroup/hugetlb          cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,hugetlb
│ │ └─/sys/fs/cgroup/devices          cgroup      cgroup      rw,nosuid,nodev,noexec,relatime,devices
│ ├─/sys/fs/pstore                    pstore      pstore      rw,nosuid,nodev,noexec,relatime
│ ├─/sys/fs/bpf                       bpf         bpf         rw,nosuid,nodev,noexec,relatime,mode=700
│ ├─/sys/kernel/config                configfs    configfs    rw,relatime
│ └─/sys/kernel/debug                 debugfs     debugfs     rw,relatime
├─/dev                                dev         devtmpfs    rw,nosuid,relatime,size=4030284k,nr_inodes=1007571,mode=755
│ ├─/dev/shm                          tmpfs       tmpfs       rw,nosuid,nodev
│ ├─/dev/pts                          devpts      devpts      rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000
│ ├─/dev/mqueue                       mqueue      mqueue      rw,relatime
│ └─/dev/hugepages                    hugetlbfs   hugetlbfs   rw,relatime,pagesize=2M
├─/run                                run         tmpfs       rw,nosuid,nodev,relatime,mode=755
│ └─/run/user/1000                    tmpfs       tmpfs       rw,nosuid,nodev,relatime,size=807204k,mode=700,uid=1000,gid=1000
├─/mnt/media                          systemd-1   autofs      rw,relatime,fd=29,pgrp=1,timeout=60,minproto=5,maxproto=5,direct,pipe_ino=12642
├─/tmp                                tmpfs       tmpfs       rw,nosuid,nodev
├─/home                               /dev/sda4   ext4        rw,relatime,data=ordered
└─/boot                               /dev/sda1   vfat        rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=

To view a (human readable) summary of disk usage:

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
dev             3.9G     0  3.9G   0% /dev
run             3.9G  840K  3.9G   1% /run
/dev/sda2        20G   15G  3.6G  81% /
tmpfs           3.9G   80M  3.8G   3% /dev/shm
tmpfs           3.9G     0  3.9G   0% /sys/fs/cgroup
tmpfs           3.9G  8.0M  3.9G   1% /tmp
/dev/sda4        94G   12G   77G  14% /home
/dev/sda1       511M   41M  471M   8% /boot
tmpfs           789M  8.0K  789M   1% /run/user/1000
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