Openbsd /

OpenBSD bsd.rd Install Guide

Sometimes, you lack a CD-ROM or USB stick to install OpenBSD from. Other times, you may want to quickly rescue and repair damaged system files on OpenBSD. Finally, you might want to upgrade an existing install of OpenBSD. For all these cases, booting bsd.rd is the fastest way to install/repair/upgrade your system.

This is a quick guide for installing/upgrading OpenBSD using bsd.rd.

NOTE: This guide is no substitute for reading the OpenBSD FAQ. In particular, you should read the Installation Guide

At bootup, type boot bsd.rd, then press enter. NOTE: you must do this quickly to avoid automatic bootup.
NOTE: At any time during the installation, if you make a mistake, you can type ctrl+c to cancel the install process. Then, press ctrl+d to bring back the installation options.

Using drive 0, partition 3.
Loading......
probing: pc0 com0 mem[639K 126M a20=on]
disk: fd0 hd0+
>> OpenBSD/amd64 BOOT 3.67
boot> /bsd.rd
NOTE: random seed is being reused.
booting hd0a:/bsd.rd: 4227986+1770496+3891816+0+716800 [109+484896+336185]=0xae8
b50
entry point at 0xffffffff8100100

Copyright (c) 1982, 1986, 1989, 1991, 1993
        The Regents of the University of California.  All rights reserved.
Copyright (c) 1995-2025 OpenBSD. All rights reserved.  https://www.OpenBSD.org

OpenBSD 7.8 (RAMDISK_CD) #54: Sun Oct 12 13:03:06 MDT 2025
    deraadt@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/RAMDISK_CD
real mem = 520093696 (496MB)
avail mem = 498339840 (475MB)
random: boothowto does not indicate good seed
mainbus0 at root
bios0 at mainbus0
acpi at bios0 not configured
cpu0 at mainbus0: (uniprocessor)
cpu0: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz, 3192.00 MHz, 06-5e-03
cpu0: cpuid 1 edx=78ba97f<FPU,VME,DE,PSE,TSC,MSR,PAE,CX8,SEP,PGE,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2> ecx=f6d83203<SSE3,PCLMUL,SSSE3,FMA3,CX16,SSE4.1,SSE4.2,MOVBE,POPCNT,AES,XSAVE,AVX,F16C,RDRAND,HV>
cpu0: cpuid 7.0 ebx=9c23a9<FSGSBASE,BMI1,AVX2,SMEP,BMI2,ERMS,RDSEED,ADX,SMAP,CLFLUSHOPT> edx=400<MD_CLEAR>
cpu0: cpuid d.1 eax=5<XSAVEOPT,XGETBV1>
cpu0: cpuid 80000001 edx=24100800<NXE,PAGE1GB,LONG> ecx=121<LAHF,ABM,3DNOWP>
cpu0: cpuid 80000007 edx=100<ITSC>
cpu0: MELTDOWN
cpu0: 32KB 64b/line 8-way D-cache, 32KB 64b/line 8-way I-cache, 256KB 64b/line 4-way L2 cache, 6MB 64b/line 12-way L3 cache
cpu0: using VERW MDS workaround
pvbus0 at mainbus0: KVM, OpenBSD
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "OpenBSD VMM Host" rev 0x00
virtio0 at pci0 dev 1 function 0 "Qumranet Virtio 1.x RNG" rev 0x01
viornd0 at virtio0
virtio0: irq 3
virtio1 at pci0 dev 2 function 0 "Qumranet Virtio 1.x Network" rev 0x01
vio0 at virtio1: 1 queue, address fe:e1:bb:d1:ff:26
virtio1: irq 5
virtio2 at pci0 dev 3 function 0 "OpenBSD VMM Control" rev 0x00
vmmci0 at virtio2
virtio2: irq 6
isa0 at mainbus0
com0 at isa0 port 0x3f8/8 irq 4: ns8250, no fifo
com0: console
softraid0 at root
scsibus0 at softraid0: 256 targets
root on rd0a swap on rd0b dump on rd0b
WARNING: CHECK AND RESET THE DATE!
erase ^?, werase ^W, kill ^U, intr ^C, status ^T

Welcome to the OpenBSD/amd64 7.8 installation program.
(I)nstall, (U)pgrade, (A)utoinstall or (S)hell?

Follow the rest of the OpenBSD Install Guide.