extend swap space
I have a RHEL box with 16G Ram and 8G swap. I want to extend the swap space to 16G (+8G).
There is not enough space for extending swap lvm so I would like to reallocate some space from /home to swap.
Please kindly advise the steps by steps for this reallocation.
Version : RHEL 7.2 workstation
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/rhel-root 52403200 8841648 43561552 17% /
devtmpfs 8063804 0 8063804 0% /dev
tmpfs 8080448 24 8080424 1% /dev/shm
tmpfs 8080448 429828 7650620 6% /run
tmpfs 8080448 0 8080448 0% /sys/fs/cgroup
/dev/nvme0n1p2 508588 212216 296372 42% /boot
/dev/nvme0n1p1 204580 9964 194616 5% /boot/efi
/dev/mapper/rhel-home 188561452 63225364 125336088 34% /home
tmpfs 1616092 136 1615956 1% /run/user/1000
/dev/sda1 3947824 3947824 0 100% /run/media/xxxx/RHEL-7.2 Server.x86_64
$ sudo lvdisplay
[sudo] password for xxxx:
--- Logical volume ---
LV Path /dev/rhel/swap
LV Name swap
VG Name rhel
LV UUID nztdi1-tX67-eH1e-5W9K-r6LZ-yJYX-MM5dhm
LV Write Access read/write
LV Creation host, time localhost, 2018-04-07 19:19:21 +0800
LV Status available
# open 2
LV Size 7.81 GiB
Current LE 2000
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Logical volume ---
LV Path /dev/rhel/home
LV Name home
VG Name rhel
LV UUID YS62cD-arv7-OJEo-D60g-eavo-Kklu-K6WPzz
LV Write Access read/write
LV Creation host, time localhost, 2018-04-07 19:19:21 +0800
LV Status available
# open 1
LV Size 179.91 GiB
Current LE 46058
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
--- Logical volume ---
LV Path /dev/rhel/root
LV Name root
VG Name rhel
LV UUID fAyjNt-XULs-SS61-7QrX-JLO8-aXZF-9eHGmx
LV Write Access read/write
LV Creation host, time localhost, 2018-04-07 19:19:22 +0800
LV Status available
# open 1
LV Size 50.00 GiB
Current LE 12800
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
$ sudo vgs
VG #PV #LV #SN Attr VSize VFree
rhel 1 3 0 wz--n- <237.79g 64.00m
Responses
Reducing volume is not good. instead of that you can create an 8GB swap file in /home directory and enable swap on that file.
for creating swap file and configuration you can follow the URL https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/ch-swapspace#swap-creating-file
Being mindful that swap performance against swap-files is even worse than raw disk-based swap.
One wonders, however, why so much swap is "needed". If something actually needs to swap out, you've probably got some fairly serious performance problems going on and really need to consider if your system is right-sized for the task at hand.
Welcome! Check out the Getting Started with Red Hat page for quick tours and guides for common tasks.
