The appears to not offer hibernate. Neither hibernate nor hybrid sleep are available in the logout menu. Calling an XFCE command to hibernate ("xfce4-session-logout --hibernate") does nothing. Suspend is available and works.
On installation, I selected the default disk layout and got a swap space of a measly 976M. I speculated that this was not enough (the machine has 3.7Gi of physical RAM), so I added an 8 Gi swap file. That made no difference. Nor did upgrading to linux-image-5.15.0-0.bpo.3-amd64 make any difference. According to this article, "echo disk | sudo tee /sys/power/state", etc. should work, and it does. This leads me to think that this is an XFCE problem, not a kernel issue. https://www.cloudsavvyit.com/9607/how-to-hibernate-or-sleep-linux-from-the-command-line/ root@ideapc:~# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 119.2G 0 disk ├─sda1 8:1 0 487M 0 part /boot ├─sda2 8:2 0 1K 0 part └─sda5 8:5 0 118.8G 0 part └─sda5_crypt 254:0 0 118.7G 0 crypt ├─debian--vg-root 254:1 0 117.8G 0 lvm / └─debian--vg-swap_1 254:2 0 976M 0 lvm [SWAP] root@ideapc:~# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root debian-vg -wi-ao---- <117.79g swap_1 debian-vg -wi-ao---- 976.00m root@ideapc:~# free total used free shared buff/cache available Mem: 3.7Gi 1.8Gi 513Mi 96Mi 1.4Gi 1.6Gi Swap: 9.0Gi 0B 9.0Gi Total: 12Gi 1.8Gi 9.5Gi root@ideapc:~# uname -a Linux ideapc 5.10.0-11-amd64 #1 SMP Debian 5.10.92-1 (2022-01-18) x86_64 GNU/Linux root@ideapc:~# root@ideapc:~# uname -a Linux ideapc 5.15.0-0.bpo.3-amd64 #1 SMP Debian 5.15.15-2~bpo11+1 (2022-02-03) x86_64 GNU/Linux root@ideapc:~# -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/