HP IO Accelerator Driver 3.1.1 Release Notes

Errata 16
Linux-specific issues
Drivers not installed after updating kernel
When the driver is installed for a specific kernel version and the kernel version is changed for any reason, the
IO Accelerator driver must be reinstalled to work with the new kernel version. RHEL5 has some processes that
minimize the need to reinstall the driver after a kernel upgrade.
Rare error on driver unload using kernels older than 2.6.24
A bug in Linux kernels prior to 2.6.24 can cause a general protection fault or other kernel error when the IO
Accelerator driver is unloaded. This bug also affects non-HP drivers. The bug has been resolved in newer
kernels. See the kernel 2.6.24 change log
(http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.24) for more information. Search for
commit 5a622f2d0f86b316b07b55a4866ecb5518dd1cf7.
Because this is a bug in the Linux kernel, HP cannot resolve this issue for older kernels.
ext4 in Kernel.org 2.6.33 or earlier might silently corrupt data
when discard (trim) is enabled
CAUTION: HP does not support the use of ext4 in Kernel.org 2.6.33 or earlier. Ext4 in
Kernel.org 2.6.33 or earlier might silently corrupt data when discard is enabled.
The ext4 filesystem in the Kernel.org kernel 2.6.33 and earlier contains a bug where the data in a portion of
a file might be improperly discarded (set to all 0x00) under some workloads. Use Version 2.6.34 or newer
to avoid this issue. For more information, see the patch
(http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=b90f687018e6d6 ) and
bug report (https://bugzilla.kernel.org/show_bug.cgi?id=15579).
The fix is included in RHEL6 pre-release kernel kernel-2.6.32-23.el6. The eventual release RHEL6 kernel is not
affected by this issue.
Discard support was added to the kernel.org mainline ext4 in Version 2.6.28 and was enabled by default.
For fear of damaging some devices, discard was set to default to disabled in Version 2.6.33-rc1 and was
back ported to 2.6.31.8 and 2.6.32.1. For more information, see the kernel patch
(http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=5328e635315734d).
Kernels 2.6.34/35 don't handle switching interrupt types
Linux kernels around 2.6.34/35 might have problems processing interrupts if the driver is loaded using one
interrupt type, unloaded, and then loaded again using a different interrupt type. The primary symptom is that
the IO Accelerator device is unusable and the kernel logs have errors containing doIRQ. For example, the
following sequence on an affected system would likely result in errors:
1. Load the driver with a default of disable_msi=1 which selects APIC interrupts:
$ modprobe iomemory-vsl
$ modprobe -r iomemory-vsl
2. Load the driver and enable MSI interrupts: