Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux

8.249. udev

Updated udev packages that fix several bugs and add two enhancements are now available for Red Hat Enterprise Linux 6.
The udev packages implement a dynamic device-directory, providing only the devices present on the system. This dynamic directory runs in user space, dynamically creates and removes devices, provides consistent naming, and a user-space API. The udev packages replace the devfs package and provides better hot plug functionality.

Bug Fixes

BZ#839172, BZ#1020856
Previously, hard disks connected to a Peripheral Component Interconnect Express SSD (PCIe SSD) did not have an entry with their IDs in the udev database, because device names did not trigger any persistent disk udev rule. As a consequence, no symbolic link was created in the /dev/disk/by-* file and the device vendor and product were shown as "Unknown" in the installer. This update adds a udev rule to supply information gathered via the ata_id utility. Now, a symbolic link in /dev/disk/by-id is created by udev and additional information is available in the udev database.
Prior to this update, a udev rule tried to write to a sysfs file without checking its existence. As a consequence, an error message was returned to syslog. With this update, the udev rule checks for the existence of the file before trying to write to it, and no inappropriate error messages appear in syslog.
The udev version in Red Hat Enterprise Linux 6 serialized modprobe execution for network cards limiting the amount of worker processes. However, if a lot of modprobes were triggered, udev could reach the limit of worker processes and stopped reacting to firmware load requests. With this update, for every modprobe process in the queue, the amount of worker processes has been increased, and firmware load requests are now executed successfully.
Previously, for a firmware loading request, the global timeout was 60 seconds by default. However, some firmware loading took longer than 60 seconds on systems with heavy I/O load during the boot process, and thus sometimes failed. The global timeout for firmware loading has been increased to 600 seconds, which is long enough for all systems to let all firmware load without a timeout.
The sr_mod kernel module was loaded via a udev rule without honoring any blacklist options. As a consequence, sr_mod was loaded although the administrator could have blacklisted this kernel module. With this update, the udev rule calls modprobe with the "-b" option, which lets modprobe check the blacklist. As a result, the sr_mod kernel module is no longer loaded automatically if the administrator chose to blacklist it.
For some data cards, a udev rule called the modem-modeswitch tool to switch the card from CDROM to modem mode. However, newer versions of the kernel did not require this call. Consequently, these data cards could not switch to modem mode. To fix this bug, the udev rule for the data cards have been removed, and switching to modem mode no longer causes problems.
In addition, this update adds the following


This update adds descriptions of scsi_id short options to the scsi_id(8) manual page, and thus scsi_id(8) is now complete.
As the "iDRAC7" network interface needed to be distinguished from normal network interfaces, it has been renamed to "idrac".
Users of udev are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.