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1.155. mdadm

1.155.1. RHBA-2011:0759: bug fix and enhancement update

An updated mdadm package that fixes several bugs and adds various enhancements is now available for Red Hat Enterprise Linux 6.
mdadm is a utility for creating, managing, and monitoring Linux MD (multiple disk) devices.
This update fixes the following bugs:
  • Previously, the "noiswmd" kernel command line option did not set the rd_NO_MDIMSM variable to 1 and the udev rules thus failed to match the option. This update removes the rule for the rd_NO_MDIMSM variable and adds the "noiswmd" and "nodmraid" command line options, which substitute the rule for rd_NO_MDIMSM. (BZ#605710)
  • The md kernel module stopped responding when attempting to stop a RAID device. This occurred due to a mutex deadlock. With this update, the underlying code was changed and the issue no longer occurs. (BZ#626762)
  • Previously, mdadm did not accept the short version of the "--export" (that is "-Y") and "--name" (that is "-N") options. This was due to missing entries in the list of short options. With this update, the missing entries have been added and the short versions of the options now work as expected. (BZ#636883)
This update also adds the following enhancements:
  • Previously, mdadm was not able to rebuild newly-connected drives automatically. This update adds the array auto-rebuild feature and allows a RAID stack to automatically rebuild newly-connected drives. (BZ#633306)
  • RAID migration is now supported: mdadm is now able to change the RAID level of an already-existing device. (BZ#633667)
  • Previously, mdadm could not add a new disk to an already-existing volume. This update adds the OLCE (On Line Capacity Expansion) feature, which allows mdadm to add new disks to an array and allocate their resources to existing volumes. (BZ#633671)
  • Previously, mdadm did not track the progress of the rebuild and level-migration operations and therefore was not able to recover their progress after a system failure. This update adds the check-pointing feature, which tracks their progress and allows mdadm to resume these operations after a system failure from the last check point. (BZ#633688)
  • This update adds SAS-SATA feature, which allows the user to disconnect a set of SATA (Serial Advanced Technology Attachment) drives from a SCSI Controller Unit (SCU) and connect it to an Advanced Host Controller Interface (AHCI) and vice versa. (BZ#633690)
  • This update limits the RAID-5 support for volumes on drives attached to the SCU on systems with the X79 chipset (code-named "Patsburg"). It inhibits the creation, assembly, activation, and level migration of RAID 5 volumes on drives attached to the SCU on these systems. (BZ#633692)
Users are advised to upgrade to this updated mdadm package, which resolves these issues and adds these enhancements.