Critical Server Boot Failure

Yesterday I rebooted my linode server, but it never came back up.

It had been running for nearly 2 months.

The errors it's showing in the lish terminal show this:

[ 1.053421] io scheduler mq-deadline registered
[ 1.054672] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[ 1.056221] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[ 1.081985] 00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 165A
[ 1.083963] Linux agpgart interface v0.103
[ 1.084753] AMD IOMMUv2 driver by Joerg Roedel jroedel@suse.de
[ 1.085720] AMD IOMMUv2 functionality not available on this system
[ 1.087554] i8042: PNP: PS/2 Controller [PNP0303:KBD,PNP0f13:MOU] at 0x60,0x2
[ 1.089577] serio: i8042 KBD port at 0x60,0x64 irq 1
[ 1.090382] serio: i8042 AUX port at 0x60,0x64 irq 12
[ 1.091394] mousedev: PS/2 mouse device common for all mice
[ 1.092396] rtc_cmos 00:00: RTC can wake from S4
[ 1.093808] input: AT Translated Set 2 keyboard as /devices/platform/i8042/s0
[ 1.095524] rtc_cmos 00:00: registered as rtc0
[ 1.096179] rtc_cmos 00:00: alarms up to one day, y3k, 114 bytes nvram, hpets
[ 1.097608] ledtrig-cpu: registered to indicate activity on CPUs
[ 1.098951] NET: Registered protocol family 10
[ 1.100886] Segment Routing with IPv6
[ 1.101529] mip6: Mobile IPv6
[ 1.102119] NET: Registered protocol family 17
[ 1.102975] mpls_gso: MPLS GSO support
[ 1.104239] mce: Using 10 MCE banks
[ 1.104861] sched_clock: Marking stable (971561321, 132649612)->(1121729060,)
[ 1.106723] registered taskstats version 1
[ 1.107427] Loading compiled-in X.509 certificates
[ 1.159801] Loaded X.509 cert 'Debian Secure Boot CA: 6ccece7e4c6c0d1f6149f3'
[ 1.161521] Loaded X.509 cert 'Debian Secure Boot Signer 2021 - linux: 4b6ef'
[ 1.163252] zswap: loaded using pool lzo/zbud
[ 1.164215] AppArmor: AppArmor sha1 policy hashing enabled
[ 1.165603] rtc_cmos 00:00: setting system clock to 2021-12-05 03:06:03 UTC )
[ 1.167352] List of all partitions:
[ 1.167942] No filesystem could mount root, tried:
[ 1.167942]
[ 1.169030] Kernel panic - not syncing: VFS: Unable to mount root fs on unkn)
[ 1.170389] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-18-amd64 #1 Deb1
[ 1.171744] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14
[ 1.173601] Call Trace:
[ 1.174075] dump_stack+0x66/0x81
[ 1.174595] panic+0xe7/0x24a
[ 1.175066] mount_block_root+0x2c2/0x2e6
[ 1.175752] ? do_early_param+0x8e/0x8e
[ 1.176419] prepare_namespace+0x130/0x166
[ 1.177057] kernel_init_freeable+0x210/0x220
[ 1.177727] ? rest_init+0xaa/0xaa
[ 1.178260] kernel_init+0xa/0x10e
[ 1.178827] ret_from_fork+0x22/0x40
[ 1.179591] Kernel Offset: 0x35e00000 from 0xffffffff81000000 (relocation ra)
[ 1.181452] ---[ end Kernel panic - not syncing: VFS: Unable to mount root f-

I have booted into rescue mode and ran rsck on the boot drive, which says it's clear, but it will not boot.

Any advice would be greatfully appreciated.