Search

7.43. dracut

download PDF
Updated dracut packages that fix several bugs and add two enhancements are now available for Red Hat Enterprise Linux 6.
The dracut packages include an event-driven initramfs generator infrastructure based on the udev device manager. The virtual file system, initramfs, is loaded together with the kernel at boot time and initializes the system, so it can read and boot from the root partition.

Bug Fixes

BZ#835646
Previously, dracut could not handle uppercase MAC addresses for the PXE "BOOTIF=" parameter. As a consequence, a machine with a dracut generated initramfs could not boot over the network, when the "BOOTIF=" parameter contained uppercase MAC addresses. With this update, dracut converts internally the MAC addresses to lowercase. Now, a machine with a dracut generated initramfs can boot over the network successfully when the "BOOTIF=" parameter contains uppercase MAC addresses.
BZ#831338
Previously, the default mount option of the /proc/ directory during boot up was "mount -t proc -o nosuid,noexec,nodev proc/proc". This resulted in inaccessible device nodes in the /proc/ directory for some kernel drivers. The default mount option of the /proc directory has been changed to "mount -t proc proc /proc" and all kernel modules now load successfully.
BZ#794751
Previously, dracut could not use the Internet Small Computer System Interface (iSCSI) and dmsquash-live module together. As a consequence, it was not possible to boot from a live medium over iSCSI. After this update, a dracut-generated initramfs, which contains the iSCSI and dmsquash-live modules, is able to boot a live medium via iSCSI. This can be done using the kernel command "root=live:LABEL=<partition-or-iso-label> netroot=iscsi: ".
BZ#813057
Previously, the new Brocade switch firmware took longer to complete the BCBx negotiation and a dracut-generated initramfs did not wait long enough for the DCBx negotiation. Now, the initramfs sleeps for three seconds after loading the "802q" kernel module and the DCBx negotiation with the new Brocade switch firmware completes successfully.
BZ#843105
When using the "live_ram" parameter for booting from live media, the dracut-generated initramfs ejected the medium. After this action, a reboot caused the machine to not boot from the medium again, even if it was intended. After this update, dracut honors the "no_eject" kernel command-line parameter. Now, if "no_eject" is given on the kernel command-line, the dracut-generated initramfs no longer ejects the live medium after copying it to the RAM.
BZ#850493
In FIPS mode, the kernel image has to be validated by a checksum. The sha512hmac tool reads the absolute path of the file to check from the checksum file. Previously, if "/boot" was not on a separate file system, dracut mounted the root file system to "/sysroot". The "/sysroot/boot" partition was not accessible with the "/boot" path and the sha512hmac tool could not access the file in "/boot" to check for. The check failed and the boot process was cancelled. Consequently, the boot processes did not succeed in FIPS mode if "/boot" was not on a separate file system. Now, dracut creates a symbolic link from the "/sysroot/boot" partition to the "/boot" partition in the initramfs and the sha512hmac tool can check the kernel image and the machine can continue booting, if the check was successful.
BZ#890081
Previously, the kernel module "scsi_dh_alua" was not included in the initramfs and as a consequence, "scsi_dh_alua" could not be preloaded via the "rdloaddriver" kernel command. The "scsi_dh_alua" kernel module is now included in the initramfs and "scsi_dh_alua" can be preloaded successfully using "rdloaddriver".
BZ#854416
Previously, dracut did not strip the kernel modules as mentioned in the man page. Consequently, initramfs size grew very big if the customer had kernel modules with a lot of debug info. The dracut utility now strips the kernel modules, except when in FIPS mode, and as a result, the initramfs size is smaller and can be loaded on machines with small memory.

Enhancements

BZ#823507
Documentation for the "rd_retry=" boot option has been added to the dracut(8) man page.
BZ#858187
The dracut utility can now boot from iSCSI on a network with virtual LANs configured, where the virtual LAN settings are stored in the iSCSI Boot Firmware Table BIOS.
Users of dracut are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.
Red Hat logoGithubRedditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

© 2024 Red Hat, Inc.