We're currently in the process switching our SAP R/3 systems over to
linux. Database is SAPDB (former ADABAS). The size is about 125 GB. For
storing RAW DEVSPACES are used (2 x RAID-5, 1 x RAID-1).
We have problems with the database under high I/O load. The kernel doesn't
report any hardware error (sync problems or the like) but the database
often dumps with signal 11 doing a 'BAD DATA PAGE' on the RAW device what
implies a full recover. No oops or hardware related errors to /dev/ida are
found in /var/log/messages.
[root@crmprod /root]# cat /proc/version
Linux version 2.2.16-22SAPenterprise (firstname.lastname@example.org) (gcc
egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)) #1 SMP Wed Aug 30
14:53:33 CEST 2000
The Redhat version used is 6.1EE order on http://erponlinux.com
Just curious if there are any known issues with RAW devices that are
bigger than 2 GB and their behaviour under high/very high load. Due to the
fact, that we have this problem on two nearly identical machines I assume
that there's no hardware problem with the controller.
The used hardware is Compaq ProLiant 5500 with 1.8 GB of RAM and 3way P-II
450 Xeon. SCSI-Controller is a Compaq SmartArray-3200 with 55 MB RAM. This
machine is certified by Redhat. We already switched the controller cache
from 50 % READ/50 % WRITE to 100 % READ/0 % WRITE to avoid data loss but
didn't come any further.
Since this is a productive system it's crucial for us getting things up.
This error was also reported to SAP under message # 0120050409 553748
Please tell me if you need additional information.
I'm glad to hear from you.
I have uploaded a new set of raw IO patches in kiobuf-2.2.18pre24.tar.gz on
This includes fixes for all known raw IO bugs, including one known to cause
possible data corruption on SAP databases under high load.
These patches are relative to the 2.2.18pre24 kernel. Could you try them?
We've got a set of raw IO patches which fix apparent problems with SAP, and
which have passed basic qualification within SAP. These will be in the next