Oracle® Linux 7 Release Notes for Oracle Linux 7.5 (aarch64)

4.1 Support limited to text-mode environments and server software

Oracle Linux 7.5 (aarch64) is engineered and tested for server-related usage only. Although packages for desktop and productivity features are built and provided, testing of these packages is limited and support for graphical mode packages is not provided in this release. You can install any of these packages on your platform, but it is possible that some of these applications may not work or may have issues that are not documented here.

Oracle does not provide support for these packages, and any assistance is community-based. If you choose to run a desktop environment or any desktop applications, you should direct any questions to the Oracle Linux for Arm community forum at https://community.oracle.com/community/technology_network_community/server_%26_storage_systems/linux/oracle-linux-for-arm.

4.2 Installation Issues

The following issues that might be encountered during installation.

4.2.1 Alternate installation options

When performing a text based installation, the installer detects the video controller and offers a graphical installation on the system video console by default. The boot menu may not offer options to perform text-based or VNC-based installation.

To perform a text-based installation you must specify the inst.text option on the boot command line. If you intend to perform a remote graphical installation over VNC, you must use the inst.vnc option, but you must also specify boot options to configure the network. Typically ip=dhcp is used for this purpose.

For more information on boot options, see Oracle® Linux 7: Installation Guide. (Bug ID 27581120)

4.2.2 Installation on an iSCSI disk

When installing on an iSCSI disk, add either ip=ibft or rd.iscsi.ibft=1 to the boot command line and specify at least one MBR or GPT-formatted disk as an installation target. Otherwise, the installation fails with the error message No valid boot loader target device found. (Bug ID 22076589)

4.2.3 Kernel panic for QLogic `cnic` module on ThunderX2 during installation

The QLogic cnic driver module is unsupported for 64-bit Arm platforms. The Cavium ThunderX2 servers include hardware that can cause the cnic driver module to load, triggering a kernel panic.

To work around the issue, blacklist the cnic module at boot using the boot option module_blacklist=cnic in the kernel command line for the installer. To prevent the module from installing or loading in the future, create the file /etc/modprobe.d/cnic.conf and ensure that it contains the following lines:

blacklist cnic
install cnic /bin/true

(Bug IDs 27011806, 28109733)

4.3 File System Bugs

The following file systems related issues pertain to Oracle Linux 7.5.

4.3.1 `btrfs`: Convert operation results in a file system that cannot be mounted

The btrfs-convert tool can be used to convert an ext4 file system to btrfs. However, if the tool attempts to convert a file system that has not been created with a sector block size that matches the system default page size, which is set to 64 KB for aarch64, the resulting file system cannot be mounted. This issue may result if the original ext4 file system is not created using the -b 65536 option, to specify a 64 KB block size. (Bug ID 28200561)

4.3.2 `ext4`: System hangs on unmount after an append to a file with negative `i_size`

While it is invalid for a file system to load an inode with a negative i_size, it is possible to create a file with a negative i_size and append to it. However, doing so causes an integer overflow in the routines underlying writeback, which results in the kernel locking up. (Bug ID 25565527)

4.4 Automatic Bug Reporting Tool

The automated reporting daemons and features provided by the Red Hat Automatic Bug Reporting Tool (ABRT) are not supported with Oracle Linux

ABRT packages and associated files, such as libreport, are included in the distribution to satisfy package dependencies and can be used to generate local bug reports but the features to automatically upload these reports are not supported. For technical assistance, contact Oracle Support by using the My Oracle Support portal or by telephone.

4.5 Manual execution of the shim first-stage bootloader may fail in the UEFI shell

Manually loading shim binaries from the UEFI shell may fail in some scenarios. The following cases are known to fail:

FS0:\EFI\redhat\shimaa64.efi
FS0:\EFI\redhat\> shimaa64.efi

FS0:\> \EFI\redhat\shimaa64.efi is known to work correctly.

A standard installation is unaffected by this bug and the problem is limited to the manual execution of shim in the UEFI shell. (Bug ID 27962691)

4.6 Kdump tools fail to create `vmcore-dmesg.txt` on systems with 64 or more CPUs

On systems with 64 or more CPUs, the crash dump tools, included with Kdump, fail to create the vmcore-dmesg.txt file which is created with the vmcore file. This may result in a segmentation fault:

...
kdump: saving to /sysroot//var/crash/127.0.0.1-2018-05-22-12:34:45/
kdump: saving vmcore-dmesg.txt
/lib/kdump-lib-initramfs.sh: line 118:   459 Segmentation fault      
$_dmesg_collector /proc/vmcore > ${_path}/vmcore-dmesg-incomplete.txt
kdump: saving vmcore-dmesg.txt failed
kdump: saving vmcore
Copying data                                      : [100.0 %] \          
eta: 0s
kdump: saving vmcore complete

The dmesg output can be retrieved manually by running crash against the vmcore and using the dmesg command once in the crash shell. (Bug ID 28064675)

4.7 Snapshots of KVM guests using UEFI fail and are unsupported

You cannot do snapshots of KVM guests if they use UEFI. In older versions of QEMU and libvirt, the tools may allow you to create the snapshot without an error or warning, but the snapshot could be corrupted. More recent versions of these tools prevent snapshot creation with an error. For example:

virsh # snapshot-create-as OL7-seboot
error: Operation not supported: internal snapshots of a VM with pflash based
firmware are not supported

(Bug ID 26826800)

4.8 Virtual machine with copied disk fails to boot

Attempting to start a virtual machine that has been created to use a copied virtual machine hard disk can fail with the messages:

Section 0 has negative size
Failed to load image: Unsupported
start_image() returned Unsupported
Error: Image at 002384AD000 start failed: Unsupported
Unloading driver at 0x002384AD000

The bootloader drops back into the UEFI Interactive Shell after it fails.

The issue is caused by a problem with the default EFI boot option that is used by the aarch64 virtual machine firmware when it attempts to boot the disk.

To work around the issue, when the virtual machine drops to the UEFI shell after it fails to boot, you can enter the following to manually load the appropriate shim binary:

Shell> FS0:\EFI\BOOT\fbaa64.efi

This is a one-time requirement and future reboots of the same virtual machine do not require manual intervention. (Bug ID 27972230)

4.9 grubby fatal error during kernel upgrade when `/boot` is on a `btrfs` subvolume

If /boot is hosted on a btrfs subvolume, GRUB 2 is unable to correctly process the initramfs and vmlinuz pathnames. This problem occurs when you update or install a new kernel and grubby attempts to update the GRUB 2 configuration. In the case where you are running a fresh installation of Oracle Linux 7.5, and you upgrade the UEK kernel, the following error is displayed:

grubby fatal error: unable to find a suitable template

When the system is rebooted after the kernel update, the system boots to the old kernel.

The workaround for this problem is to use grub2-mkconfig to regenerate the /etc/grub2/grub.cfg file immediately after the kernel has been installed or upgraded, for example:

# grub2-mkconfig -o /boot/grub2/grub.cfg

Obtain a listing of the kernel menu entries in the generated configuration as follows:

# grep -P "submenu|^menuentry" /boot/grub2/grub.cfg | cut -d "'" -f2

From the listing, select the kernel entry that you want to run as the default kernel and set this entry as the default using the following command, substituting menu entry title with the title of the kernel entry that you identified in the listing:

# grub2-set-default "menu entry title"

You can use the grub2-editenv list command to check that the saved_entry has been updated with the selected kernel menu title.

Reboot and use uname -a to check that the correct kernel is now running.

(Bug ID 22750169)

4.10 Hebrew LaTeX fonts

Installing the tex-fonts-hebrew package fails unless you first install all texlive* packages. (Bug ID 19059949)

4.11 Unable to create LXC containers on btrfs

The creation of a Linux container (LXC) may fail when the container file system is specified as btrfs. For example:

lxc-create -B btrfs --template=oracle --name=test
-- --release=7.4
lxc-create: lxccontainer.c: do_bdev_create: 936 Failed to create backing
store type btrfs
lxc-create: lxccontainer.c: do_lxcapi_create: 1419 Error creating backing
store type btrfs for test
lxc-create: lxc_create.c: main: 274 Error creating container test

LXC is available as a technology preview in this release and some functionality may not work correctly. (Bug ID 27823142)

4.12 Unable to create Oracle Linux 7 LXC containers on NFS

The creation of Oracle Linux 7 containers fails when the root file system (/container) is hosted on an NFS share. The problem occurs because the iputils package in Oracle Linux 7 releases, (Updates 4 and 5) is built to use the Linux file extended attributes [xattr(7)] security capabilities(7). The NFS protocol does not support these file capabilities, so the iputils package might not be installed into an NFS files system. For example, when attempting to create an Oracle Linux 7.4 container, the installation fails while installing the iputils package, producing the following error:

Error unpacking rpm package iputils-20121221-7.el7.x86_64
error: unpacking of archive failed on file /usr/bin/ping: cpio: cap_set_file
error: iputils-20121221-7.el7.x86_64: install failed

Similar issues are seen when attempting to install the initscripts and systemd packages while creating an Oracle Linux 7.3 container.

This issue occurs on both NFSv3 and NFSv4.

Oracle Linux 6 containers are not affected. LXC is available as a technology preview in this release and some functionality may not work correctly. (Bug ID 25024258)

4.13 isql unable to connect via `unixODBC`

The isql command shipped in the unixODBC package fails to connect to the database and returns the error:

[ISQL]ERROR: Could not SQLConnect

This issue is related to an unsolved dynamic library requirement for unixODBC. The requirement also affects the ODBC driver for MySQL shipped in the mysql-connector-odbc package. (Bug ID 26861190)

4.14 Segmentation fault when running bluedevil-wizard

The bluedevil-wizard, available in the bluedevil package, is unable to connect or locate bluetooth devices and fails with a segmentation fault when it is run. (Bug ID 27101618)

4.15 dsktune command fails with an unsupported error message

The dsktune command included with the 389 Directory Server base package, 389-ds-base, fails with an error message notifying that the system does not have support for cx16, a feature commonly available on x86 platforms:

ERROR: This system does not support CMPXCHG16B instruction (cpuflag cx16).
nsslapd-enable-nunc-stans must be set to "off" on this system.
In a future release of Directory Server this platform will NOT be
supported.

ERROR  : The above errors MUST be corrected before proceeding.

The dsktune command helps to check that a system meets requirements and can provide information that helps with the configuration, but is not required to run the 389 Directory Server. (Bug ID 26861135)

Chapter 4 Known Issues