I'm using Linux Mint serena on an Intel NUC with an internal Samsung SSD 850 EVO M.2 250 GB hard drive.

Under computer I find my file system and a drive called Samsung SSD 850 EVO M.2 250 GB. This part of the hard drive can't be accessed and as far as I can tell isn't mounted, its about 20 Gb in size.

This is listed as sda3 under drives but I don't see this area listed anywhere else, can I reduce its size or even mount it?


Filesystem     1K-blocks    Used Available  Use% Mounted on
udev             8138676       0   8138676    0% /dev
tmpfs            1632016    9676   1622340    1% /run
/dev/sda2      223315548 6559660 205389080    4% /
tmpfs            8160068     808   8159260    1% /dev/shm
tmpfs               5120       4      5116    1% /run/lock
tmpfs            8160068       0   8160068    0% /sys/fs/cgroup
/dev/sda1         523248    3684    519564    1% /boot/efi
cgmfs                100       0       100    0% /run/cgmanager/fs
tmpfs            1632016      16   1632000    1% /run/user/1000


sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=8138676k,nr_inodes=2034669,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,noexec,relatime,size=1632016k,mode=755)
/dev/sda2 on / type ext4 (rw,relatime,errors=remount-ro,data=ordered)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (rw,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
efivarfs on /sys/firmware/efi/efivars type efivarfs (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/pids type cgroup (rw,nosuid,nodev,noexec,relatime,pids,release_agent=/run/cgmanager/agents/cgm-release-agent.pids)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb,release_agent=/run/cgmanager/agents/cgm-release-agent.hugetlb)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event,release_agent=/run/cgmanager/agents/cgm-release-agent.perf_event)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,clone_children)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=38,pgrp=1,timeout=0,minproto=5,maxproto=5,direct)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
mqueue on /dev/mqueue type mqueue (rw,relatime)
tracefs on /sys/kernel/debug/tracing type tracefs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
/dev/sda1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,relatime)
cgmfs on /run/cgmanager/fs type tmpfs (rw,relatime,size=100k,mode=755)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=1632016k,mode=700,uid=1000,gid=1000)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)

Ok, the output of lsblk -f was:

├─sda1 vfat C71D-C090 /boot/efi
├─sda2 ext4 ce782317-5811-44c4-a648-a7ee8f11c483 /
└─sda3 swap 8185f231-2fa6-4127-a5a6-147ec29f4fd7 [SWAP]

Whats happens if I reduce the size of sda3? And how would I achieve that, with the swapon command? The output of the free command:

              whole       used     free          gemns.  Puffer/Cache available  
Memory:    16320136      930864    14159408      203220     1229864    14859036  

memory: ------16664572-----------0----------16664572

  • 3
    Please list the output of lsblk -f. It should show all block devices and partitions in the system. – Mioriin Feb 12 '17 at 13:25
  • 2
    I suggest swapon -s as it is likely swap space – Chunko Feb 12 '17 at 15:31
  • the out put of the lsblk -f command is: – Andrew Feb 18 '17 at 9:58

The partition sda3 is designated as a swap partition, that means it's intended (1) as a place to hold the content of the RAM during hibernation and (2) as a sort of RAM "extension" where contents of the RAM are stored when they are not currently used, so the main RAM can be used for other processes etc. that are "life" and need more RAM.

An SSD has a limited amount of write cycles, os using a swap space on an SSD which is constantly written to is often not recommended.

With swapon, you can activate this partition to use as a swap partition. You can't use swapon to somehow reduce the size of the partition. See man swapon for details.

If you don't use hibernation, and if you have enough RAM, you can delete this partition with any partitioning tool (fdisk, gparted, whatever Mint prefers). You can also (carefully, or you'll damage your existing data) enlarge the sda2 parition to use the space that is freed up this way (google for tutorials how to that, if you run into difficulties, open a new question on stackexchange).

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