This article provides guidance to troubleshoot Linux virtual machine (VM) boot issues caused by filesystem errors.
You can't connect to an Azure Linux virtual machine (VM) by using the Secure Shell Protocol (SSH), or the VM Agent status in the Azure portal isn't Ready. When you run the Boot diagnostics in the Azure portal or connect to the Serial Console, you see log entries that resemble the following examples:
- Not all examples will be present.
- A mounting failure doesn't always result in a VM entering emergency mode. If the issue is with certain critical filesystems, the VM may not use emergency mode.
Example 1: Fail to mount ext4 filesystem
EXT4-fs (sda1): INFO: recovery required on readonly filesystemEXT4-fs (sda1): write access will be enabled during recoveryEXT4-fs warning (device sda1): ext4_clear_journal_err:4531: Filesystem error recorded from previous mount: IO failureEXT4-fs warning (device sda1): ext4_clear_journal_err:4532: Marking fs in need of filesystem check.
Example 2: Fail to mount ext Logical Volume Manager (LVM) device
[ 14.382472] EXT4-fs error (device dm-0): ext4_iget:4398: inode #8: comm mount: bad extra_isize 4060 (inode size 256)[ 14.389648] EXT4-fs (dm-0): no journal found<snipped>[FAILED] Failed to mount /opt/data.
Example 3: Fail to mount xfs filesystem
[ 8.543984] XFS (sdc1): Metadata CRC error detected at xfs_agi_read_verify+0xd0/0xf0 [xfs], xfs_agi block 0x10[ 8.553867] XFS (sdc1): Unmount and run xfs_repair[ 8.558993] XFS (sdc1): First 128 bytes of corrupted metadata buffer:[ 8.564893] 00000000: 58 41 47 49 00 00 00 01 00 00 00 00 00 1f ff c0 XAGI............[ 8.572847] 00000010: 00 00 00 40 00 00 00 06 00 00 00 01 00 00 00 3d ...@...........=[ 8.580476] 00000020: 00 00 00 60 ff ff ff ff ff ff ff ff ff ff ff ff ...`............[ 8.588219] 00000030: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................[ 8.596280] 00000040: ff 07 f8 ff ff ff ff ff ff ff ff ff ff ff ff ff ................[ 8.603575] 00000050: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................[ 8.610849] 00000060: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................[ 8.619261] 00000070: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................[ 8.629731] XFS (sdc1): metadata I/O error in "xfs_trans_read_buf_map" at daddr 0x10 len 8 error 74[ 8.637799] XFS (sdc1): xfs_imap_lookup: xfs_ialloc_read_agi() returned error -117, agno 0[FAILED] Failed to mount /data.See 'systemctl status data.mount' for details.[DEPEND] Dependency failed for Local filesystems.
Example 4: Boot into emergency mode
You are in emergency mode. After logging in, type "journalctl -xb" to viewsystem logs, "systemctl reboot" to reboot, "systemctl default" or "exit"to boot into default mode.Give root password for maintenance(or press Control-D to continue):
The log entries above indicate disk corruption. In certain situations, disk corruption will prevent the VM from fully booting. Various issues can cause disk corruption, such as Linux kernel problems, driver errors, errors in the underlying physical or virtual hardware, and so on.
To resolve the Linux VM boot issues caused by filesystem errors, recover the VM by repairing the disk corruption. To repair the disk corruption, follow these steps:
Identify which disk is corrupted.
Identify filesystem type.
Select recovery mode (online or offline).(Video) [SOLVED] How To Fix The "No Space Left on Device" Error On Linux In A VM
Prepare the recovery environment according to the recovery mode you select:
- Prepare environment for online recovery
- Prepare environment for offline recovery
Use command-line tools to repair the problematic filesystem on the disk.
- Repair ext4 filesystem
- Repair xfs filesystem
- It's important to back up critical data because data loss may occur on the recovered disk.
- Before you make changes to a disk, take a snapshot to preserve the current state of the disk, even if it's in an error state. Fixing the disk corruption will change the data on the disk, which will carry risk.
Identify which disk is corrupted
To determine which disk is corrupted, download the serial log for your VM by using the Serial Console or Boot diagnostics, examine the log entries during boot up, and then look for the specific error calling out which disk or mount is failing.
Here are three log entry examples. In these examples, note the text in parenthesis, which reports the corrupted device.
In the following example, the corrupted device is
[ 14.285807] XFS (sdc1): Mounting V5 Filesystem[ 14.426283] XFS (sdc1): Metadata CRC error detected at xfs_agi_read_verify+0xde/0x100 [xfs], xfs_agi block 0x10[ 14.426284] XFS (sdc1): Unmount and run xfs_repair<snipped>[FAILED] Failed to mount /opt/parent.
In the following example, the partition where a filesystem error occurs is
EXT4-fs (sda1): INFO: recovery required on readonly filesystemEXT4-fs (sda1): write access will be enabled during recoveryEXT4-fs warning (device sda1): ext4_clear_journal_err:4531: Filesystem error recorded from previous mount: IO failureEXT4-fs warning (device sda1): ext4_clear_journal_err:4532: Marking fs in need of filesystem check.<snipped>[FAILED] Failed to mount /boot.
In the following example, the corrupted device is
dm-2. It's a Linux Device Mapper device, which indicates an LVM volume.
[ 18.014318] EXT4-fs (dm-2): VFS: Can't find ext4 filesystem[FAILED] Failed to mount /home.See 'systemctl status home.mount' for details.[DEPEND] Dependency failed for Local File Systems.[DEPEND] Dependency failed for Mark the need to relabel after reboot.
If the disk device being called out uses a name of the format "sdXN" where X is a letter from a-z and N is an optional partition number, it means that the disk is raw and can be operated on by using the /dev/sdXN path.
If the disk device being mounted uses a name such as /dev/mapper/vgname/lvname, /dev/vgname/lvname, or dm-N, it means that an LVM device is used. Take care to recognize all disk physical volumes (PVs) which may be in use.
It's not supported for the LVM volume group (VG) to contain the OS disk and any number of data disks. For such a scenario, there's a high risk of data loss. However, multiple data disks are permissible in an LVM VG.
When determining the mapping of OS disk references to Azure disk objects:
- For marketplace images, the root filesystem (/), /boot and /boot/efi is located on the OS disk.
- For LVM based images, many other system mounts may exist such as /home, /tmp, /usr, /var, /var/log, and /opt.
- Extra filesystems created for applications are located on data disks, for example, /data, /datadisk, or /sap. Configure them properly so that the system can boot even if there's an error. If a data disk is a device that boots into emergency mode, see prevent boot failure.
Identify filesystem type
While doing initial identification, the only method to determine the disk type is using the serial log as previously examined in Identify which disk is corrupted. When the disk device is reported in the serial log, errors will be displayed from the Linux kernel module for the filesystem. Note each line where
XFS is specified. For any other filesystem types, the log is in the same area. The filesystem noted in the log entries is determined by the /etc/fstab file. Take care to verify that the specified format is correct when performing a repair.
Once you have access to an interactive shell, run the
lsblk command with the
-f flag as follows to show devices, paths (if the filesystem is mounted), and the filesystem type that's read from the disk itself.
[root@localhost ~]# lsblk -fNAME FSTYPE LABEL UUID MOUNTPOINTsda|-sda1 vfat 93DA-8C20 /boot/efi|-sda2 xfs d5da486e-fdfe-4ad8-bc01-aa72b91fd47d /boot|-sda3`-sda4 LVM2_member pdSI2Q-ZEzV-oT6P-R2JG-ZW3h-cmnf-iRN6pU |-rootvg-tmplv xfs 9098eb05-0176-4997-8132-9152a7bef207 /tmp |-rootvg-usrlv xfs 2f9ff36c-742d-4914-b463-d4152801b95d /usr |-rootvg-optlv xfs aeacea8e-3663-4569-af25-c52357f8a0a3 /opt |-rootvg-homelv xfs a79e43dc-7adc-41b4-b6e1-4e6b033b15c0 |-rootvg-varlv xfs c7cb68e9-7865-4187-b3bd-e9a869779d86 /var `-rootvg-rootlv xfs d8dc4d62-ada5-4952-a0d9-1bce6cb6f809 /sdb`-sdb1 ext4 1dac7c4c-bf8e-4964-8a59-7359eef53d0a /mntsdc LVM2_member CRWEZQ-iLhH-ev0b-BAaA-dfLD-nbPT-GgtG0r`-vgapp-lvapp xfs 733e25ee-565f-4bfa-a2a1-2451efd25cd1sdd`-sdd1 ext4 704d9fb1-2207-4bb9-998c-029f776dc6d2 /opt/data
Here are some important points in the output:
- By using the ASCII art display, you can see that there are LVM volumes present because there's an LVM2_MEMBER FSTYPE for sda4 containing objects with names such as
rootvg-homelvisn't mounted, which is denoted by the empty MOUNTPOINT field.
rootvg-homelvhas filesystem type XFS. It's a contrast with the EXT4 mount error during booting up. If the filesystem type is inconsistent, trust the
lsblkoutput rather than the contents of fstab.
Select recovery mode
You can recover a VM online through emergency mode or single-user mode or offline by using a rescue VM.
Requirements for online recovery
The Serial Console access to the VM.
If emergency mode is used, the Serial Console must display an emergency mode prompt, the root account must be unlocked, and the password must be known.
If single-user mode is used, the root password isn't needed. The single-user mode may be used when a filesystem other than required system partitions such as root (
Requirements for offline recovery
If the Serial Console requirements for online recovery can't be met, perform offline recovery by using a rescue VM. To perform offline recovery, the ability to create a VM and manage disks in Azure is required. Alternatively, you can use a functioning Linux VM with Azure-level access to the corrupted disks.
Prepare environment for online recovery
When the emergency mode is displayed in the sign-in prompt as follows, enter the root password:
Welcome to emergency mode! After logging in, type "journalctl -xb" to viewsystem logs, "systemctl reboot" to reboot, "systemctl default" or ^D totry again to Give root password for maintenance(or press Control-D to continue):
If the root password isn't known, or the root account is locked, as in the following output, use single-user mode:
Welcome to emergency mode! After logging in, typCannot open access to console, the root account is locked.See sulogin(8) man page for more details.Press Enter to continue.
If the online recovery environment is unusable, proceed to offline recovery.
Prepare environment for offline recovery
In single disk VMs, or when the failing mount is a system partition such as the root filesystem (
/usr, the most reliable method to repair the disk is by using a rescue VM to gain access to the disk. You can create a rescue VM automatically or manually.
For automated creation of a rescue VM, see Azure Virtual Machine Repair. For manual creation of a rescue VM, see creating a recovery VM. In either case, don't mount the volumes from the problem disk because a filesystem must not be mounted for repair utilities to operate.
Perform filesystem repair
Before repairing the filesystem, ensure that the following steps have been completed:
- The problem disk and partition, or LVM volume structure, has been identified.
- The filesystem type has been determined.
- (Optional) A copy of the problem disk, or disks in a spanned LVM volume group, has been attached to a rescue VM.
- Access to an interactive shell has been secured by using access to the disk.
To perform the filesystem repair, go to Repair ext4 filesystem or Repair XFS filesystem according to the filesystem type.
No matter what recovery mode is used, the commands to perform the filesystem repair are the same. The emergency shell may have limitations. If the commands aren't available in an emergency mode environment, or there are errors about unknown filesystem types, prepare environment for offline recovery.
The commands to repair the filesystem may not fix all errors. They work around disk corruptions, but data loss still may occur. Once the command output states that the filesystem is clean, reassemble the original VM with the repaired disk, and boot the VM to verify data.
In the following sections,
/dev/sdc1 is the corrupted filesystem in raw mode, and the LV
homelv in the VG
rootvg is the LVM volume. Substitute these values for the actual corrupted filesystem in all instances.
Repair ext4 filesystem
fsck [-y] FILESYSTEM command to repair an ext4 filesystem. Specify the filesystem as a disk partition for a raw filesystem, for example
/dev/sdc1, or the LVM logical volume path
Here's a command output example:
[root@vm1dev ~]# fsck /dev/sdc1fsck from util-linux 2.23.2e2fsck 1.42.9 (28-Dec-2013)ext2fs_check_desc: Corrupt group descriptor: bad block for block bitmapfsck.ext4: Group descriptors look bad... trying backup blocks.../dev/sdc1 was not cleanly unmounted, check forced.Resize inode not valid. Recreate<y>? yesPass 1: Checking inodes, blocks, and sizesPass 2: Checking directory structurePass 3: Checking directory connectivityPass 4: Checking reference countsPass 5: Checking group summary informationFree blocks count wrong for group #0 (23508, counted=23509).Fix<y>? yesFree blocks count wrong (8211645, counted=8211646).Fix<y>? yes/dev/sdc1: ***** FILE SYSTEM WAS MODIFIED *****/dev/sdc1: 11/2097152 files (0.0% non-contiguous), 176706/8388352 blocks[root@vm1dev ~]#
The output shows that the confirmation to modify the filesystem is requested three times. If there are many requests, press CTRL+C and restart
fsck with the
-y flag to assume "yes" to all questions. If any files are reported as being placed in
lost+found, manually identify them and place them in proper locations.
If some errors occur and are subsequently fixed, run the
fsck command again. Repeat until the
fsck command exits with the
clean status. Refer to the following output as an example:
[root@vm1dev ~]# fsck /dev/sdc1fsck from util-linux 2.23.2e2fsck 1.42.9 (28-Dec-2013)/dev/sdc1: clean, 11/2097152 files, 176706/8388352 blocks[root@vm1dev ~]#
Repair xfs filesystem
Here are commands to repair an XFS filesystem:
xfs_repair [-n] FILESYSTEM
xfs_repair [-L] FILESYSTEM
mount FILESYSTEM MOUNTPOINT
To repair an XFS filesystem, follow these steps:
Check filesystem errors by using the
xfs_repair -ncommand, as follows:
xfs_repair -n /dev/rootvg/homelv
If the check succeeds, continue with the repair mode by removing the
-nflag, which will try to fix any encountered errors, as follows:
For XFS filesystems, journaled but uncommitted changes are dealt with by mounting the filesystem. If you encounter the following error during the troubleshooting, attempt a mount and view the results.
ERROR: The filesystem has valuable metadata changes in a log which needs to be replayed
If a recovery VM is used, create a directory for a temporary mount point, such as
/recovery, and mount the filesystem. If the recovery environment is in emergency or single-user mode, mount the filesystem on its intended location. Refer to the following commands as examples:
mount /dev/rootvg/homelv /recovery
If the journaled changes aren't written when you mount filesystems, use the
-L flag to discard the journal and mount the filesystem as if all changes are successfully completed. When the
-L flag is used, data loss will occur because the log shows incomplete file operations are being discarded.
xfs_repair -L /dev/rootvg/homelv /recovery
Prevent boot failure
nofail option is specified when mounting filesystems, the corruption of a non-critical filesystem may not prevent Linux from booting fully. For more information about
nofail, see Mount the disk. Most mounts aside from the root (
/var can be done with
If you have questions or need help, create a support request, or ask Azure community support. You can also submit product feedback to Azure community support.
- Verify that your boot disk is not full. ...
- Examine your virtual machine instance's serial port output. ...
- Enable interactive access to the serial console. ...
- Verify that your disk has a valid file system. ...
- Verify that the disk has a valid master boot record (MBR).
- Stop the affected VM.
- Take a snapshot for the OS disk of the VM.
- Create a virtual hard disk from the snapshot.
- Attach and mount the virtual hard disk to another Linux VM for troubleshooting purposes.
- Connect to the troubleshooting VM.
The most common reason why virtual machine boot failures occur is that the required hardware resources aren't available. Microsoft Hyper-V and other server virtualization platforms revolve around the idea that most workloads have relatively modest hardware requirements.How do I create a boot diagnostic in AZ VM? ›
Sign in to the Azure portal, and then select the virtual machine. In the Help section, select Boot diagnostics, then select the Settings tab. In Boot diagnostics settings, select the boot diagnostics with managed storage account or custom storage account. Save the change.How do I force a VM to boot into BIOS? ›
Right Click the VM from web-client/ HTML client and select edit setting. Select 'Boot Options' under 'VM Option' Check for Force BIOS Setup.Which file is used to troubleshoot virtual machine? ›
VMAN is designed to help ensure admins can troubleshoot VM issues with speed and accuracy.How do I troubleshoot booting errors in Linux? ›
- Step 1: Check your BIOS settings. The BIOS (Basic Input/Output System) is a firmware interface that controls your computer's hardware. ...
- Step 2: Run a file system check. ...
- Step 3: Reinstall your boot loader. ...
- Step 4: Check for hardware issues.
To fix Linux boot snags, make sure that everything on your hard disk is mounted, enter a chroot setup and next use the grub-install command to install GRUB again. If you decide to install GRUB in the MBR and the hard disk is addressed by the device file /dev/sda, you would use the command grub-install /dev/sda.How do I troubleshoot Linux problems? ›
- Check your network configuration. ...
- Check the network configuration file. ...
- Check the server's DNS records. ...
- Test the connection both ways. ...
- Find out where the connection fails. ...
- Firewall settings. ...
- Host status information.
- Type cmd in the Search Box, or use Win+R keys and enter cmd to open Command Prompt application.
- Navigate to the location where you install VMware.
- Type the following command: vmware-vdiskmanager-R"the qualified path to the corrupt VMDK file”
- Press Enter.
Right-click your VM, and then select Open Console. Launch the VMware Remote Console. From the vsphere client, right-click the VM name, and click the Edit Settings option. Click the Options tab, and then select Boot Options and choose the option to force entry into the BIOS setup screen.How do I force a VM to boot into safe mode? ›
Anyway, to start a VM in safe mode you need to modify the settings of the VM. In Hyper-V Manager select Settings, then go to Automatic Start Action and set a startup delay there.How do I run UEFI diagnostics? ›
- Hold the power button for at least five seconds to turn off the computer.
- Turn on the computer and immediately press esc repeatedly, about once every second. ...
- On the HP PC Hardware Diagnostics (UEFI) main menu, click System Tests. ...
- Click Fast Test, and then click Run once.
- Open the VMware Workstation Pro application, select the virtual machine from the left pane, and then click Edit virtual machine settings from the right pane.
- In the Hardware tab, click CD/DVD (SATA).
- Select Use ISO image file, click Browse, and then select the ISO file.
- Click Open and click OK.
Use ISO to boot virtual machine is a necessary skill for VM users. If your there is a problem with your VM, and you can't start it, you could use ISO booting to repair your system. You could also install guest operating system from ISO images on a fresh virtual machine.How to enable UEFI in VM? ›
- Browse to the virtual machine in the vSphere Client inventory.
- Right-click the virtual machine and select Edit Settings.
- Click the VM Options tab, and expand Boot Options.
- Under Boot Options, ensure that firmware is set to EFI.
- Select your task. Select the Secure Boot check box to enable secure boot. ...
- Click OK.
- Shutdown the VM.
- Go to PRISM and Update the VM configuration changing from "Legacy BIOS" to "UEFI":
- Alternatively you can also use acli from any CVM: nutanix@cvm:~$ acli vm.update <vm name> uefi_boot=true.
- Power on the VM, open the console and you should see the Nutanix UEFI Screen.
- VM >> Settings >> Hardware >> CD/DVD drive.
- On the right side, select Connected, Connect at power on and Use ISO image file, then click Browse to locate the file.
- Click OK.
Possible causes of VMDK file corruption
Virus or malware: Virus or malware present in your system or enter through external sources can severely damage your VM. Unexpected file termination: Immediate termination of VMDK files without saving it properly may result in failure to open VMDK in VMware again.
On VirtualBox, if you create a virtual machine or install an app on the guest device, you will probably need to mount an ISO file to access the setup files.
In VMware Workstation or VMware ACE, the default location of virtual machine files is the directory /home/username/vmware , where username is the user who created the virtual machine. In VMware Server, the default location of virtual machine files is the directory /var/lib/vmware/Virtual Machines .How to check Linux filesystem for errors? ›
- To check all the default file systems, enter: fsck. This command checks all the file systems marked check=true in the /etc/filesystems file. ...
- To fix minor problems with the default file systems automatically, enter: fsck -p.
- To check a specific file system, enter: fsck /dev/hd1.
- Place your SLES/SLED 10 CD 1 or DVD in the drive and boot up to the CD or DVD. ...
- Enter the command "fdisk -l". ...
- Enter the command "mount /dev/sda2 /mnt". ...
- Enter the command "grub-install --root-directory=/mnt /dev/sda". ...
- Once this command completes successfully reboot your system by entering the command "reboot".
The causes of computer failure to boot up can be broken down into four categories as follows: Bad electrical connection. Power supply failure. Operating system failure.How to install boot repair in Linux? ›
- Adding the PPA repositories.
- Updating the apt package list.
- Viewing the contents of the PPA repository list file.
- Listing all available packages.
- Installing the Boot Repair tool.
- Launching the Boot Repair tool.
- Viewing Boot Repair's main window.
Reboot With the System Request Key
To kill all processes and reboot Linux, hold down “Alt” and “SysRq” together, then type “REISUB” (without quotes). The SysRq key, which stands for System Request, is also known as the PrtSc, or Print Screen, key.
Boot-Repair is a simple tool to repair frequent boot issues you may encounter in Ubuntu like when you can't boot Ubuntu after installing Windows or another Linux distribution, or when you can't boot Windows after installing Ubuntu, or when GRUB is not displayed anymore, some upgrade breaks GRUB, etc.How to repair Linux file system? ›
- Enter the boot menu and choose Advanced Options.
- Select the Recovery mode and then “fsck”.
- When prompted to remount the root file system choose “Yes”.
- Once done, resume the normal boot.
- How to Choose the Best Linux Data Recovery Tools?
- TestDisk - Partition and Disk Recovery Tool.
- Mondo Rescue - Network Drive Recovery Utility.
- ddrescue - GNU Data Recovery Utility.
- Redo Backup and Recovery - Easiest GUI Recovery Utility.
- PhotoRec - Photo Recovery Utility.
- Boot Repair - Live CD File Recovery.
The nslookup command
This information is useful for troubleshooting as it helps to identify whether the issue is local due to a specific server, or something more extensive. You can also use it to run reverse DNS queries by providing the IP address instead of a hostname: $ nslookup 209.132.
- Click File > Open > Browse and then go to the location or folder where the document (Word), workbook (Excel), or presentation (PowerPoint) is stored. ...
- Click the file you want, and then click the arrow next to Open, and click Open and Repair.
Step 1: Run CMD as administrator. Step 2: Type DISM /Online /Cleanup-Image /RestoreHealth. Step 3: Let it run its course. This will most likely resolve any issues related to your operating system.How to repair virtual machine in VMware? ›
- Reboot The Virtual Machine. Sounds funny? ...
- Use Windows Command Prompt. The CMD (Command Prompt) utility is a free built-in tool that assists Windows PC users in making critical changes and executing advanced tasks on their Windows OS computers. ...
- Using a Professional VMDK Repair Software.
- Shut down or turn off the virtual machine.
- Edit the settings of the virtual machine.
- Browse to Add Hardware, select Legacy Network Adapter, and click Add.
- Click OK to save your changes.
As an emulation of a physical computer, most virtual machines require a BIOS to control booting and input/output operations. While a VM BIOS is similar to a BIOS on a physical computer or server, its functionality is often more limited compared to the BIOS of a physical machine.How to set boot disk in vmware? ›
- Select Window > Virtual Machine Library.
- Select a virtual machine in the Virtual Machine Library window and click Settings.
- Under Other in the Settings window, click Startup Disk.
- Click the startup device to use.
- Click Restart.
When you can't open Settings to get into safe mode, restart your device from the Windows sign-in screen. On the Windows sign-in screen, press and hold the Shift key while you select Power > Restart .How to boot Linux in safe mode VMware? ›
At the VMware startup screen, repeatedly press F8 on the virtual keyboard until the Advanced Boot Options screen displays. Use the arrow keys to select Safe Mode, and then press Enter to restart the VM in safe mode.How do I force UEFI to boot in safe mode? ›
Switch the computer on and off repeatedly with the power button. When nothing else works on your Windows 10 computer, you can try to open the UEFI blue screen by repeatedly and quickly turning the computer on and off using the power button. You'll then be able to initiate a restart in safe mode.How to detect UEFI or BIOS in Linux? ›
Check if you are using UEFI or BIOS on Linux
The easiest way to find out if you are running UEFI or BIOS is to look for a folder /sys/firmware/efi. The folder will be missing if your system is using BIOS. Alternative: The other method is to install a package called efibootmgr.
From the Windows desktop, press the Windows and R keys to open the Run window. In the Open: field of the Run window, type dxdiag. Click OK or the Enter key to open the DirectX* Diagnostic Tool.How do you check if your system is installed in UEFI mode? ›
- Press Windows + R keys together to launch the Run box. Type MSInfo32 and hit Enter.
- On the right pane, find the "BIOS Mode". If your PC uses BIOS, it will display Legacy. If it is using UEFI so it will display UEFI.
This is usually F1 or F2, but the necessary key to press will be displayed on the screen. Note: You can force the power-on sequence to stop on the BIOS screen, as follows: In vSphere Client or Web Client, right-click the VM and click Edit Settings > VM Options (or Options) tab > Boot Options.What is the boot process of a VM? ›
First, resources are allocated to the VM by the hypervisor. Second, the BIOS of the VM (or more recent technologies such as UEFI) locates and loads the boot loader into the memory. Next, the boot loader loads the corresponding kernel binary, initializes various devices and mounts the root file system.How to set boot priority in VMware? ›
Open the Edit Settings dialog box for the virtual machine. Click the Options tab and select the Boot Options section. Request a force entry into the BIOS setup screen by selecting Force BIOS setup, or add delay in milliseconds in Power on Boot Delay, within which you can press Esc or F2. Click OK.What would cause the VM not to boot? ›
There are several causes for this error: The operating system (OS) is unable to boot due to the partition holding the Boot Configuration Data (BCD) Store is inactive. The OS is unable to boot due to BCD Corruption. The OS is unable to boot due to the boot sector not being found.Should you dual boot or use a VM? ›
In terms of dual boot vs virtual machine interactivity, virtual machine is better. The good interactivity of virtual machine is reflected in the following two ways: By using the virtual machine, you can run multiple operating systems (the host system and guest systems) at the same time.What types of errors might cause a computer not to boot? ›
- Bad electrical connection.
- Power supply failure.
- Operating system failure.
- Hardware failure.
The failure of a VM to power on may be caused by any of the following reasons: ESXi OS problems. File corruption. File locks.How do I restart a frozen virtual machine? ›
- Exit VMware Workstation.
- Browse to the following location: C:\ProgramData\VMware\VMware Workstation.
- Open the config.ini file in a text editor, e.g. Notepad.
- Add the following lines: prefvmx.minVmMemPct = "100" ...
- Save the file and close the text editor.
- Launch VMware Workstation and start the virtual machine.
- services.sh restart – restart all ESXi services.
- /etc/init.d/vpxa restart – restart vCenter Agent on host.
- cat /etc/chkconfig. ...
- vmkping –I vmk1 10.10.10.1 – send ICMP request to 10.10.10.1 through vmk1 interface.
- nc –z 10.10. ...
- vmkfstools –i test.vmdk testclone.vmdk – clones test.vmdk to testclone.vmdk.
- Restart the computer.
- Open the BIOS. ...
- Go to the Boot tab.
- Change the order to position the hard disk as the 1st option. ...
- Save these settings.
- Restart the computer.
If you turn on the computer and see this error message: “Disk boot failure - insert system disk and press Enter," it signifies that BIOS cannot read your disk, which prevented Windows from loading. Some causes of this error include a damaged hard drive, incorrect BIOS boot order, a corrupted OS, and faulty data cables.What causes booting problems? ›
A defective motherboard, video card, or piece of RAM could cause Windows not to boot properly. To test for hardware issues, you can create and use an Ultimate Boot CD, which contains a collection of troubleshooting utilities to try and identify and sometimes fix hardware problems.Can a VM get corrupted? ›
If a VM's OS is corrupted, you can retrieve the boot disk data to recover the VM. To recover the boot disk, you must first create a temporary VM using a Google-provided image, because the snapshot of the source VM might be corrupted.What causes VM to crash? ›
RESOLUTION. Compare the size of a full backup to the amount of space available in the VMWare datashare of the virtual machine. If there is little or no room left on the datastore when the snapshot is being taken, it can cause the server to crash or reboot.How do I restore my VM machine? ›
- Navigate to Backup center in the Azure portal and click Restore from the Overview tab.
- Select Azure Virtual machines as the Datasource type, and then select a Backup instance.
- Select a VM and click Continue.
- In the next screen that appears, select a restore point to use for the recovery.
Typically, rebooting your VM will take about 30-60 seconds. From the Linux terminal, type the sudo reboot command, or on Windows hit Win + R (or Ctrl + Esc + R ) and type shutdown -f -r -t 0 to reboot a VM.How do I Restart a Linux virtual machine? ›
- sudo reboot.
- sudo shutdown -r now This will perform a system shutdown in a proper way and then reboot the computer.
- sudo init 6.
- sudo poweroff.
- sudo shutdown -h now This will perform a system shutdown in a proper way. ...
- sudo halt is another way to shutdown.
- sudo init 0.
Hard reboot is a reboot as if you switched off and on your VM from power. Soft reboot is like a "reboot" command from the command prompt.
- Open the Server Automation domain.
- From the navigation tree in the Server Automation domain, click Virtualization > Virtual Machine Management > Power Configuration to open the list of Power Configuration Tasks.
- From the Power Configuration list, select Restart VM (soft).
Quickly press F2 (in OS X or macOS, press Fn + F2) to enter the VMware BIOS. The BIOS boot screen is visible for only about one second.