On Fri, 2009-03-06 at 12:22 +1300, Paul Ward wrote: > # ls /boot > ls: reading directory /boot: Input/output error What's in dmesg at this time? > I have been told that the disks use multipath but I have no experience > of this to date. > I know the disks are on a SAN but as yet have not been able to locate > them using the IBM SAN manager. > > Linux version 2.6.18-53.1.21.el5PAE So, RHEL5.1? > (brewbuilder@xxxxxxxxxxxxxxxxxxxxxxxxxxxx) (gcc version 4.1.2 20070626 > (Red Hat 4.1.2-14)) #1 SMP Wed May 7 08:56:33 EDT 2008 > Vendor: IBM Model: 1814 FAStT Rev: 0916 > Type: Direct-Access ANSI SCSI revision: 05 So it's an IBM FAStT SAN? These are active/passive storage arrays that require use of a multipath hardware handler to properly manage switching between the active and passive paths and preventing I/O being sent to a controller that cannot handler it. The I/O errors that you see are a result of things trying to access the passive paths (e.g. partition scanning, lvm label scanning, udev/hal probes etc.). RHEL5.1 included the old device-mapper hardware handlers. These will only take effect once multipath has configured the devices and only handle path switching in the event of a path failure (i.e. you'll still see I/O errors if something tries to access one of the underlying paths directly rather than via the multipath device map). RHEL5.3 introduces the scsi device handler framework as a replacement for the device-mapper hardware handlers (this appeared upstream in 2.6.26). Whether you decide to update or not it's probably worth carefully checking the current multipath configuration on the system as this is a very common area for configuration mistakes. Regards, Bryn. -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
