unable to install: "no cdrom found"

udotirol

New Member
Mar 9, 2018
14
4
3
48
Hi,

I'm trying to get my feet wet with proxmox, but so far fail even with the very first step of installing it from an USB stick, using the lastest ISO available (proxmox-ve_5.1-3.iso).

No matter what I do, the installation process ends pretty early, just after the kernel has been booted, complaining that "no cdrom found" and throwing me out into a minimal shell:

Unfortunately, as a new user, I'm neither allowed to post images for "anti-spam measurement reasons" nor links to screenshots, so here's a specially crafted link to the screenshot (you'll certainly figure out how to make it work): hXXps:// i.imgur.com/qtfo0Ue.jpg (sidenode: this policy is extremely annoying, in particular for new, potential customers ...)

I've followed the instructions on the wiki, but to no avail: https://pve.proxmox.com/wiki/Install_from_USB_Stick

Code:
dd if=proxmox-ve_5.1-3.iso of=/dev/sdf bs=1M
I've also tried with various USB sticks, completely wiped them using wipefs

Code:
wipefs -a /dev/sdf
... or even more low level using dd, zero'ing the first bytes of the block device

Code:
dd if=/dev/zero of=/dev/sdf bs=512 count=1
... and I've tried on various computers, but nothing worked so far.

Any further ideas?
 

udotirol

New Member
Mar 9, 2018
14
4
3
48
just one additional thing I noticed:

after I transfer the ISO to the USB drive using whatever kind of tool (dd, imagewriter, I even tried the Windows based "etcher.io" tool mentioned in the admin guide), unplug the USB stick and replug it, dmesg shows me those lines:

Code:
[ 7351.886579] usb 1-2: new high-speed USB device number 6 using xhci_hcd
[ 7352.027355] usb-storage 1-2:1.0: USB Mass Storage device detected
[ 7352.027515] scsi host7: usb-storage 1-2:1.0
[ 7353.047567] scsi 7:0:0:0: Direct-Access     SanDisk  Cruzer Switch    1.26 PQ: 0 ANSI: 6
[ 7353.047928] sd 7:0:0:0: Attached scsi generic sg5 type 0
[ 7353.048857] sd 7:0:0:0: [sdf] 15633408 512-byte logical blocks: (8.00 GB/7.45 GiB)
[ 7353.049846] sd 7:0:0:0: [sdf] Write Protect is off
[ 7353.049848] sd 7:0:0:0: [sdf] Mode Sense: 43 00 00 00
[ 7353.050172] sd 7:0:0:0: [sdf] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[ 7353.066524] sd 7:0:0:0: [sdf] Attached SCSI disk
[ 7431.916552] GPT:Primary header thinks Alt. header is not at the end of the disk.
[ 7431.916555] GPT:1208395 != 15633407
[ 7431.916556] GPT:Alternate GPT header not at the end of the disk.
[ 7431.916556] GPT:1208395 != 15633407
[ 7431.916557] GPT: Use GNU Parted to correct GPT errors.
[ 7431.916568]  sdf: sdf1 sdf2 sdf3 sdf4
I've seen this GPT message for any of the USB sticks I've tried and none of them ever had a GPT header on it. And, to add to this, to be sure, I've even completely wiped one USB stick using dd like this:

Code:
dd if=/dev/zero of=/dev/sdf bs=4M
took very long to complete, but nevertheless did not change the warning about the GPT mismatch.
 
Feb 24, 2018
58
5
8
I don't have a fix for you, but I reinstalled Proxmox once, and found that installing/reinstalling from DVD works fine, but I ran into the same issue with a USB keyfob that you did.
 

fabian

Proxmox Staff Member
Staff member
Jan 7, 2016
3,707
572
133
it seems like the installer does not find your USB disk (or identify it correctly as PVE installer device). if you want to manually debug it, you'd need to find out which block device your USB stick is and then check at which point the detection logic fails. the code in the installer's initrd does the following:
Code:
reqid=$(cat /.pve-cd-id.txt)
for i in /sys/block/hd* /sys/block/sr* /sys/block/scd* /sys/block/sd*; do
  if [ -d $i ] && [ $(cat $i/removable) = 1 ]; then
    path="/dev/${i##*/}"
    echo "testing cdrom $path"
    if mount -t iso9660 -o ro $path /mnt >/dev/null 2>&1; then
      if [ -r /mnt/.pve-cd-id.txt ] && [ "X$(cat /mnt/.pve-cd-id.txt)" = "X$reqid" ]; then
        echo "found proxmox cdrom"
        cdrom=$path
        break
      fi
    fi
    umount /mnt
  fi
done
so either your USB stick is not classified as a block device at all, or it does not have the removable flag set (for whatever reason).

if you just want the easy way out, you can install Debian Stretch and install PVE on top (see https://pve.proxmox.com/wiki/Install_Proxmox_VE_on_Debian_Stretch)

(sorry for the "no-links-for-new-users" rule, without it the amount spam was too high, and fortunately legitimate users on a technical forum can easily work around it like you did :))
 
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udotirol

New Member
Mar 9, 2018
14
4
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thx for that code fragment.

It indeed looks like none of the five or six USB thumb drives I've played with have that flag set, so that's the reason for the installation not to start.

Given the high amount of repeated questions about why installations from USB sticks don't work, maybe removing that check is feasible?

At least from my potential new customer's POV, such a situation is bad, because if evaluating software already fails at this very early installation stage, chances are high that I simply won't go on testing the software.

Of course I could install debian first and put proxmox on top of it as you mentioned, but in terms of evaluation, if a vendor supplies "easy to use" ISOs including instructions how to put them on USB sticks, I admit that do have the expectation for this to work.
 

web2wire

New Member
Mar 19, 2018
2
0
1
56
I have discovered ProxMox and am trying to install it to evaluate and have hit the same issue. The difference for me is that I am trying to install it on a cloud hosting service (Linode in my case, I can't post the link but google "linode custom dinstribution" for the guide) which uses a disk image as the installer. The PMG installer does not see this as a removable disk and so fails. I imagine this would be the case on Google Cloud or Azure etc as I don't image custom ISOs are mounted as removable.

It would be useful if there was a way to indicate the install image as a boot option or something and skip this removable media check altogether.
 

BrettR

Member
Dec 8, 2017
17
0
6
60
Hello,

Question for 'Fabian'.
Is there any way to get a current version of the (proxmox installer) code segment that you posted above?
i.e.
---------------------------------------------------------------------------------------------
reqid=$(cat /.pve-cd-id.txt)
for i in /sys/block/hd* /sys/block/sr* /sys/block/scd* /sys/block/sd*; do
if [ -d $i ] && [ $(cat $i/removable) = 1 ]; then
path="/dev/${i##*/}"
echo "testing cdrom $path"
if mount -t iso9660 -o ro $path /mnt >/dev/null 2>&1; then
...
----------------------------------------------------------------------------------------------

During my recent installation attempts..there was a 'delay' (of several seconds), where the script
was performing some type of test on the CD-ROM. I don't see that functionality in the above code
snippet.

Next topic.
I installed the proxmox 5.0 ISO onto a USB 2.0 key, using the dd command. When I tried to install proxmox onto a laptop, the
installer would fail and report the common 'can't find cd-rom' error message.
(BTW, for my USB device, /sys/block/sdb device did have the 'removable' flag set.)

Next, I used the 'etcher' application to install the proxmox image onto the USB key.
When I retried the installation.. it worked (most of the time).

I did have one instance where the etcher based USB key also issued the 'can't find cd-rom' error message.

Could this be some type of 'timeout' error in the installer? (On some of the installation attempts,
I plugged in a network cable. For the others, I did not. I'm wondering if the OS had some additional load..
when the networking cable was plugged in..and this somehow affected the timing of the proxmox installer.)

I'm hoping to isolate the cause of the sporadic 'can't find cd-rom' errors.

Thanks in advance.
--Brett
 

fabian

Proxmox Staff Member
Staff member
Jan 7, 2016
3,707
572
133
Hello,

Question for 'Fabian'.
Is there any way to get a current version of the (proxmox installer) code segment that you posted above?
i.e.
---------------------------------------------------------------------------------------------
reqid=$(cat /.pve-cd-id.txt)
for i in /sys/block/hd* /sys/block/sr* /sys/block/scd* /sys/block/sd*; do
if [ -d $i ] && [ $(cat $i/removable) = 1 ]; then
path="/dev/${i##*/}"
echo "testing cdrom $path"
if mount -t iso9660 -o ro $path /mnt >/dev/null 2>&1; then
...
----------------------------------------------------------------------------------------------

During my recent installation attempts..there was a 'delay' (of several seconds), where the script
was performing some type of test on the CD-ROM. I don't see that functionality in the above code
snippet.

Next topic.
I installed the proxmox 5.0 ISO onto a USB 2.0 key, using the dd command. When I tried to install proxmox onto a laptop, the
installer would fail and report the common 'can't find cd-rom' error message.
(BTW, for my USB device, /sys/block/sdb device did have the 'removable' flag set.)

Next, I used the 'etcher' application to install the proxmox image onto the USB key.
When I retried the installation.. it worked (most of the time).

I did have one instance where the etcher based USB key also issued the 'can't find cd-rom' error message.

Could this be some type of 'timeout' error in the installer? (On some of the installation attempts,
I plugged in a network cable. For the others, I did not. I'm wondering if the OS had some additional load..
when the networking cable was plugged in..and this somehow affected the timing of the proxmox installer.)

I'm hoping to isolate the cause of the sporadic 'can't find cd-rom' errors.

Thanks in advance.
--Brett
all of that is in the "init" script in the initramfs. just boot in debug mode (or mount the iso and initramfs), and read it ;) then you can try step by step and see where your device needs to be handled differently or whatever the issue is.
 

Murad

New Member
Aug 31, 2018
3
0
1
41
all of that is in the "init" script in the initramfs. just boot in debug mode (or mount the iso and initramfs), and read it ;) then you can try step by step and see where your device needs to be handled differently or whatever the issue is.
I've encountered the problem. After "no cdrom found" message I entered 'fdisk -l' command and noticed that my USB flash drive can't be found in the output.

The easiest way to find suitable USB flash drive is to plug it in right after "no cdrom found". If it's compatible you'll see something like "/dev/sdb1 found" message from system. Write the ISO file to this drive and try to install from it. It worked in my case.
 

shantanu

Active Member
Mar 30, 2012
105
6
38
Hi @udotirol,
I understand the confusion/frustation if usb installs don't work, but I would encourage you not to give up.

I personally have been a very happy user of Proxmox for many (many) years and would recommend Proxmox wholeheartedly.

If it is possible, how about setting up pxe based installation from a central pxe server?
 

udotirol

New Member
Mar 9, 2018
14
4
3
48
@shantanu no worries, I've already overcome this issue by finding a suitable boot USB stick.

Those were my first attempts to get my feet wet with Proxmox, so installing a PXE server just for giving Proxmox a test drive on one computer would have been a little bit of an overhead.
 
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AlexLup

Member
Mar 19, 2018
171
8
18
38
Hmm I am also experiencing this issue when I put the ISO on an external SSD + enclosure..
 

moocan

New Member
Jan 7, 2019
1
0
1
49
Hello,

Just to leave my newcomer feedback:
I'm never fought at this point to install ... euh not to install ... but just boot a linux product to install it for 10 years ... and do not succeed !

- Checked sha256sum of iso : OK
- Tested proxmox with 10 USB drive : None working always "no cdrom found"
- Tested proxmox with many tools dd, unetbootin, rufus, ... None is working
- Tested each USB and tools on three computers (UEFI, not UEFI, RAID, not RAID, simple laptop) : None is booting proxmox install
- Each time USB key is detected correctly using fdisk -l
- All these 10 usb drive have been tested and are fully working with all major Linux distrib (Debian, Ubuntu, pFsense, CentOS 7, 6 and even working with CentOS 5 and HP tools) and boot without troubles
- After "no cdrom found" error if you reinsert USB key, dmesg is reporting same error as already reported by udotirol in post #2 ...
GPT:Alternate GPT header not at the end of the disk ... even if you have erased all the USB keys and created a msdos Partition Table.
- If you insert proxmox created USB from iso in a Linux distrib, many error are reported when inserting USB Key as ... invalid FS ... and so on ... None of the other Linux distrib have these errors after using dd !

So what to do to install Proxmox
- Install a PXE server ?
- Install Windows to try others tools ?
- burn a CD ?

Seems that something need to be changed to create an iso/install which is working with dd, ....!
Instruction from wiki "dd if=proxmox-ve_*.iso of=/dev/XYZ bs=1M" is just a joke !

What is a good product if you can't install it ... or if two days are required to install it or simply fail as me ?



All my best regards
Moo
-
 
Last edited:

JAZ013

New Member
I've installed proxmox a bunch of times and this is the first time I have got this error. Installing on an older reclaimed system. Thanks to the script posted above I have found that it is the "-t iso9660" argument to the mount command. With it, I get the same error I see on boot. Without it the Usb drive mounts fine.

So, questions. Why is it the argument used if it's not needed to mount the drive? Is it possible to remove it from my init script? Why did writing with Rufus, which is how I have always made bootable proxmox installers, suddenly not create the correct filesystem?
 

kroem

Member
Jul 12, 2016
44
0
6
34
I'm running into the same problem here, is there anyway to get some support so it actually installable? Never had this problem when I first installed my pve hosts some 3-4 years ago.

Ok, so I can install Debian and PVe over it, but getting a zfs root mirror is a whole other process. The PVE iso should just work, right?
 

LittenT

New Member
May 6, 2019
1
1
3
39
Hi all, I just joined and am super new to Proxmox, but I think I have a solution that may help. I too was getting the no cdrom error and it was terribly vexing. I had just about given up on Proxmox and was about to go to another platform when I figured out a solution. The trick for me was to create two USB keys, one with Rufus on Windows, and the other with Etcher. I started the install with the usb drive I created with Rufus and when the cdrom error came up, I plugged the usb drive that I created with Etcher and that did the trick! From there, installation was straightforward and easy.

I know this isn’t the ideal method but it worked for me on all three of my nodes that I set up. So I wanted to share this with you and hope that it’ll help anyone else who was stuck like I was!
 
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m5e

New Member
May 8, 2019
3
0
1
31
Hi Proxmox, @fabian
I'm also tried many many things with rufus, etch etc and always "no cdrom found".
I also plugged a CD/DVD drive with burned ISO in my Supermicro and also, no cdrom found... really??
What is the problem here? That should not happen, I'm in an POC and it looks like I have to go with vSphere :-(
 
Last edited:

t.lamprecht

Proxmox Staff Member
Staff member
Jul 28, 2015
2,132
327
103
South Tyrol/Italy
We test our ISOs regularly on a range of HW from our testing lab, Super Micro boards are included there and work fine here, every ISO release to the public gets at least tested once in this way.
For some of you with problems you could try using the "Virtual Media" feature of a IPMI console, works also fine here (tested too on super micro, asus, ... boards) as a workaround.

Can you post some more infos, not only the "flash" method, but the details of the USB stick used (capacity, maybe model) and the model of the motherboard + bios, so that we can try to reproduce this problems here, because as of now we just can't.
 

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