Windows Server 2008 x64 SP2 SAN disks falls off

Question

Hello!
We have a Windows Server 2008 Standart SP2 x64, which is connected via two HBAs QLogic QLA2440 to a Storage Xyratex F5402. On DS5402 are located three LUNs for the corporate file storage. These LUNs are displayed in Windows Server as local disks E F G.
As the MPIO software it is used Xyratex Storview Pathmanager 6.00.5016.14 (Microsoft MPIO Driver 6.0.6002.18005) in Failover\Failback configuration, and three disks are adjusted for work on three different ways.
It is all normally worked since 2008
But problems have begun with the beginning of this year.
In operation time any of the SAN disks falls off. With a F5402 all is normal and its logs there are no errors.
In Windows Event System Log the folowing errors and warnings:
EventID: 515, Source: xyrsp200 (Xyratex F5402E Multi-Path Device Specific Module). The path for logical drive [SN: 60050CC00020188D0000000000000007] has failed over to [0005 4:0:1:2] because of a path error.
EventID: 23, Source: mpio. Errors in all ways. \Device\MPIODisk2 it will be removed.
EvetID: 260, Source: xyrsp200 The active path on logical drive [SN: 60050CC00020188D0000000000000007] has been switched to the preferred path on [0005 5:0:0:2].
EventID: 15, Source: disk. Access to the device \Device\Harddisk5\DR5 while is impossible
and further an disk erors...
Disk reloading in Windows Disk Manager doesn't help. I am compelled to reboot the server. After reboot all works as though anything and wasn't to the following such case.
As fall off not all LUNы at once (one can fall off, others and will to work normally) a problem probably either in Windows or in Xyratex Storview Pathmanager.
After adjustment of monitoring I have found out that at the moment of failure the current queue of a falling disk was 6 and the size of operation of record on a disk has sharply increased.
May be the disk simply hasn't sustained loading (though strange - Fiber-Chaneell, and High-Perfomance Disks Storage). In Windows it can be somehow possible to optimize operations of work with disks that there were no such falls.
I need a help !!!
Andy Mishechkin

Answer 1

Hello 
I've configured my SCOM service on windows server 2008 r2 sp1, and it's database is placed on 2 disks on SAN storage (HP p9000). since MPIO is configured, sometimes SCOM was stop working. I looked Disk management console and I saw DB disks were gone! This problem
solves when I restart the server. This was happening frequently and I've changed the MPIO configuration policies. that get better but it was happening in a bit longer periods. 
I searched and found out I have to install Fibrechannel hotfix (fcinfo_amd64) and Windows6.1-KB2470949-v2-x64 and the mentioned patch above. I did this and for last 3 months that was ok but last night it happens again. 
It is our monitoring system and send very important messages. please help me.  
may be this information helps:
Alert
occuring sequence in LOG files:
All paths have failed.
\Device\MPIODisk2 will be removed.
A fail-over on \Device\MPIODisk2
occurred.
The device,
\Device\Harddisk3\DR3,
is not ready for access yet.
The description for Event ID 304 from source hpxpdsm cannot be found.
Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer
thanks in advance