Disk disappeared from system after cold reboot .

gbip · 04-27-2018, 09:22 AM

Hello everyone,
I am creating this thread because I currently have a problem with OpenBSD 6.2 running on a VM on an OVH server (OpenBSD ovhvps.openstacklocal 6.2 GENERIC#132 amd64).

I followed this tutorial for the installation, since it is not natively supported by OVH.

Now my problem is that I have a disk that changed DUID an I can't find it. I have two hard-drive : a 20 Gb one for the system, and a 50 Gb one for the data. On the OVH control panel both disk are labeled as connected.

Now this is my `/etc/fstab` :

Code:

a8e29a56dba81f59.b none swap sw
a8e29a56dba81f59.a / ffs rw 1 1
a8e29a56dba81f59.k /home ffs rw,nodev,nosuid 1 2
a8e29a56dba81f59.d /tmp ffs rw,nodev,nosuid 1 2
a8e29a56dba81f59.f /usr ffs rw,nodev 1 2
a8e29a56dba81f59.g /usr/X11R6 ffs rw,nodev 1 2
a8e29a56dba81f59.h /usr/local ffs rw,wxallowed,nodev 1 2
a8e29a56dba81f59.j /usr/obj ffs rw,nodev,nosuid 1 2
a8e29a56dba81f59.i /usr/src ffs rw,nodev,nosuid 1 2
a8e29a56dba81f59.e /var ffs rw,nodev,nosuid 1 2
00e91f190cdc9d32.a /var/www/data ffs rw,nodev,auto 1 2

The problem is that upon loading fsck and mount can't find `00e91f190cdc9d32`.

Here is the output of `sysctl -a | grep -i disk` :

Code:

hw.disknames=sd0:a8e29a56dba81f59,fd0:
hw.diskcount=2
machdep.bios.diskinfo.128=bootdev = 0xa0000204, cylinders = 1023, heads = 255, sectors = 63
machdep.bios.diskinfo.129=bootdev = 0xa0010204, cylinders = 1023, heads = 255, sectors = 63

So the OS do see an other hard drive but does not assign a DUID to id.

I also have to mention that at first this setup was working perfectly but I had to do a cold reboot and then this problem appeared.

I hope I didn't make too much grammar mistakes since English is not my native langage I try to do my best to write as perfectly as possible.

Please be patient, I am still a student and posting here to learn as much as possible. I spent a few weeks searching for solutions, reading man pages and trying to understand the root of this problem but I just
can't figure it out.

Do you have any idea what should I do to recover this disk and finally mount it ? What about my strange fstab file, why is it mentionning GUID and not disk path ? Does it comes from my installation process ?

Finally, here is the output of `dmesg`

Code:

OpenBSD 6.2 (GENERIC) #132: Tue Oct  3 21:18:21 MDT 2017
    deraadt@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC
real mem = 4177371136 (3983MB)
avail mem = 4043841536 (3856MB)
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.8 @ 0xf6880 (10 entries)
bios0: vendor SeaBIOS version "2:1.10.2-58953eb7" date 04/01/2014
bios0: OpenStack Foundation OpenStack Nova
acpi0 at bios0: rev 0
acpi0: sleep states S3 S4 S5
acpi0: tables DSDT FACP SSDT APIC
acpi0: wakeup devices
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel Core Processor (Haswell, no TSX), 2394.81 MHz
cpu0: FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SS,SSE3,PCLMUL,VMX,SSSE3,FMA3,CX16,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,FSGSBASE,BMI1,AVX2,SMEP,BMI2,ERMS,INVPCID,ARAT
cpu0: 64KB 64b/line 2-way I-cache, 64KB 64b/line 2-way D-cache, 512KB 64b/line 16-way L2 cache
cpu0: ITLB 255 4KB entries direct-mapped, 255 4MB entries direct-mapped
cpu0: DTLB 255 4KB entries direct-mapped, 255 4MB entries direct-mapped
cpu0: smt 0, core 0, package 0
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 1000MHz
ioapic0 at mainbus0: apid 0 pa 0xfec00000, version 11, 24 pins
acpiprt0 at acpi0: bus 0 (PCI0)
acpicpu0 at acpi0: C1(@1 halt!)
"ACPI0006" at acpi0 not configured
"PNP0F13" at acpi0 not configured
"PNP0700" at acpi0 not configured
"PNP0A06" at acpi0 not configured
"PNP0A06" at acpi0 not configured
"PNP0A06" at acpi0 not configured
pvbus0 at mainbus0: KVM
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "Intel 82441FX" rev 0x02
pcib0 at pci0 dev 1 function 0 "Intel 82371SB ISA" rev 0x00
pciide0 at pci0 dev 1 function 1 "Intel 82371SB IDE" rev 0x00: DMA, channel 0 wired to compatibility, channel 1 wired to compatibility
pciide0: channel 0 disabled (no drives)
pciide0: channel 1 disabled (no drives)
uhci0 at pci0 dev 1 function 2 "Intel 82371SB USB" rev 0x01: apic 0 int 11
piixpm0 at pci0 dev 1 function 3 "Intel 82371AB Power" rev 0x03: apic 0 int 9
iic0 at piixpm0
vga1 at pci0 dev 2 function 0 "Cirrus Logic CL-GD5446" rev 0x00
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
virtio0 at pci0 dev 3 function 0 "Qumranet Virtio Network" rev 0x00
vio0 at virtio0: address fa:16:3e:b6:bc:d2
virtio0: msix shared
virtio1 at pci0 dev 4 function 0 "Qumranet Virtio SCSI" rev 0x00
vioscsi0 at virtio1: qsize 128
scsibus1 at vioscsi0: 255 targets
virtio1: msix shared
virtio2 at pci0 dev 5 function 0 "Qumranet Virtio Storage" rev 0x00
vioblk0 at virtio2
scsibus2 at vioblk0: 2 targets
sd0 at scsibus2 targ 0 lun 0: <VirtIO, Block Device, > SCSI3 0/direct fixed
sd0: 20480MB, 512 bytes/sector, 41943040 sectors
virtio2: msix shared
virtio3 at pci0 dev 6 function 0 "Qumranet Virtio Memory" rev 0x00
viomb0 at virtio3
virtio3: apic 0 int 10
isa0 at pcib0
isadma0 at isa0
fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
com0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
com1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo
pckbc0 at isa0 port 0x60/5 irq 1 irq 12
pckbd0 at pckbc0 (kbd slot)
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pms0 at pckbc0 (aux slot)
wsmouse0 at pms0 mux 0
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
usb0 at uhci0: USB revision 1.0
uhub0 at usb0 configuration 1 interface 0 "Intel UHCI root hub" rev 1.00/1.00 addr 1
vmm0 at mainbus0: VMX/EPT
uhidev0 at uhub0 port 1 configuration 1 interface 0 "QEMU QEMU USB Tablet" rev 2.00/0.00 addr 2
uhidev0: iclass 3/0
ums0 at uhidev0: 3 buttons, Z dir
wsmouse1 at ums0 mux 0
vscsi0 at root
scsibus3 at vscsi0: 256 targets
softraid0 at root
scsibus4 at softraid0: 256 targets
root on sd0a (a8e29a56dba81f59.a) swap on sd0b dump on sd0b
fd0 at fdc0 drive 1: density unknown
fd1c: hard error reading fsbn 0 (st0 41<abnrml> st1 80<end_of_cyl> st2 0 cyl 0 head 0 sec 1)
fd1c: hard error reading fsbn 64 of 64-67 (st0 21<seek_cmplt> st1 0 st2 0 cyl 0 head 0 sec 1)
fd1c: hard error reading fsbn 1024 of 1024-1027 (st0 21<seek_cmplt> st1 0 st2 0 cyl 0 head 0 sec 1)

fatmac · 04-28-2018, 04:01 AM

My guess is that no one knows anything about 'a VM on an OVH server', as this is mainly Linux people that dabble with BSD.

If you don't get any help here, maybe try posting your problem on Daemon Forums.
http://daemonforums.org/forumdisplay.php?f=11

jggimi · 04-28-2018, 07:30 AM

As noted already on OpenBSD's misc@ mailing list, your dmesg shows only one drive, sd0. The second, missing drive, is not accessible to the virtual machine. The kernel does not see it.

https://marc.info/?l=openbsd-misc&m=152484416002455&w=2

Edited to add:

The DUID is set on a drive when an OpenBSD disklabel is created. The DUID is used to locate the drive in the event of device renumbering -- for example, from sd3 to sd2. The DUID can be used in mount(8) commands, and is used in the fstab(5) configuration file.

You can change the DUID, but only by expressly altering it with the disklabel(8) command.

However, in your situation, the DUID doesn't matter. The device is not visible to the kernel.

jggimi · 04-28-2018, 10:26 AM

Posting a follow-up as the hw.diskcount value may be confusing you. The count is 2 devices: sd0, and fd0.

The fd0 device is a floppy disk drive.

The sd0 device is the only logical SCSI device visible to the kernel. The sd(4) devices can be actual SCSI drives, serial ATA, USB, or in virtual machines, VirtIO devices. In your kernel, the single sd(4) device is the latter, a vioblk(4) VirtIO device.

I recommend you contact your VPS vendor for support, since the second drive is not visible to your virtual machine at all.

gbip · 04-28-2018, 02:16 PM

Thanks a lot for your answers, I contacted OVH support which told me that everything is okay on their side. The technician told that it should be a software problem on my side and that I should follow their guide.

I am currently negotiating with the support so that they take a closer look.

jggimi · 04-29-2018, 08:00 AM

Based solely on the dmesg(8) report, I doubt the fault lies in OpenBSD. You could prove it by booting another OS in the same virtual machine, and count how many VirtIO drives it reports.

But to do that, you would need to alter the virtual machine's configuration to add that OS's media -- which alters the environment.

gbip · 04-29-2018, 03:17 PM

I don't think I have the knowledge to boot an other OS without grub.

Anyway I am impressed by the quality of your answers guys, I didn't think that this forum was that much active.

Thanks a lot, I will get back once OVH answered me.

jggimi · 04-29-2018, 03:34 PM

My thought was that you could boot the install media of another OS, such as a CD or DVD .iso, and determine from that install/rescue OS how many VirtIO drives it sees.