Posted on behalf of Jordan Hargrave, Linux Software Engineer
Although Dell does not officially support Ubuntu Linux on Dell PowerEdge servers, Ubuntu 12.04 LTS or later kernels will work on PowerEdge systems with a few caveats.
The sb_edac (and i7core_edac) drivers must be blacklisted or patched with an upstream version. Depending on which kernel you have, the sb_edac driver has a bug that may cause a temporary system hang when processing machine check events. This is not a Dell-specific issue. The bug will cause NMI watchdog timeout events to occur within the kernel message log:
[ 94.816130] [<ffffffff81640ac9>] do_nmi+0xf9/0x360
[ 94.816134] [<ffffffff81640130>] nmi+0x20/0x30
...
[ 94.816150] [<ffffffff8164356d>] notifier_call_chain+0x4d/0x70
[ 94.816153] [<ffffffff816435ca>] atomic_notifier_call_chain+0x1a/0x20
[ 94.816157] [<ffffffff81029b49>] mce_log+0x29/0x180
The acpi_pad and mei drivers must also be blacklisted as they can cause performance problems on Dell PowerEdge servers. The acpi_pad driver is the ACPI Processor Aggregator driver, used for power saving features. However it can interfere with the firmware if power saving features enabled in BIOS. The acpi_pad driver is still undergoing development and may be best to blacklist the driver at this time, it is not a necessary driver for system operation.
The mei driver can cause error messages with watchdog timer and also prevent proper shutdown.
To blacklist a driver, you can either edit /etc/modprobe.d/blacklist.conf or create your own /etc/blacklist/xxxx.conf file and add the lines:
blacklist acpi_pad
blacklist mei
blacklist sb_edac
blacklist i7core_edac
Resources:
kernel patch for sb_edac driver:
http://lkml.indiana.edu/hypermail/linux/kernel/1112.2/03268.html
ACPI PAD driver bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=42981
Information on mei driver:
http://ubuntuforums.org/showthread.php?t=1970325