This file contains the limitations that were published at the release time of older version of IBM DS Storage Manager host software. IMPORTANT: The listed limitations are cumulative. However, they are listed by the DS4000/DS5000 storage subsystem controller firmware and Storage Manager host software releases to indicate which controller firmware and Storage Manager host software release that they were first seen and documented. New limitations with Storage Manager version 10.70.xx.10 release (controller firmware 07.70.xx.xx). 1. Storage Manager Error 1000 - Could not communicate with the storage...., can occur when actions such as clearing the configuration on a large system (i.e. 448 drives with a DS5300). The Storage Manager has a 120 second timeout and retries 2 more times when retrieving status. Some actions such as this may take 8 minutes or longer. 2. Array Management Window shows 2048 volume copies allowed when only 2047 maximum volume copies can be created. For a given array, at least one source volume will be present for the volume copy feature; hence, the actual number of “copy relationships” is one less than the maximum volume allowed. 3. FDE Drive in “Security Locked” state is reported as “incompatible” state in the drive profile. The drive can be recovered by importing the correct lock key. 4. Deselecting product components using keyboard when installing Storage Manager still installs them. You will have to use mouse for individual component selection. New limitations with Storage Manager version 10.60.xx.17 release (controller firmware 07.60.xx.xx). 1. This version of the Storage Manager installation package includes the IBM Storage Manager Profiler. This is also referred to as Support Monitor in some of the IBM publications. The following system restrictions apply: Note: Do not use laptops or I/O-attached hosts for installing the IBM Storage Manager Profiler unless these items fulfill all of the following requirements. 1. Minimum 1GB memory, 1.5 GB preferred 2. Minimum 1GB hard drive space, 1.5 GB preferred 3. On average 15 to 20 minutes installation duration 4. Static IP address required 5. The Storage Manager Profiler is installed by default with the IBM DS Storage Manager Install Anywhere (SMIA) package with the Typical (Full Installation) selection. To not install the Storage Manager Profiler, select Custom then deselect Support Monitor. 6. A pre-existing MySQL database on the host must be manually uninstalled before you can install the Storage Manager Profiler. 7. The Storage Manager Profiler installation includes the Apache Tomcat webserver application. Any other pre-existing applications that use Apache Tomcat must be uninstalled before you install the Storage Manager Profiler. 8. Make sure the Storage Manager Profiler directory structure is removed from antivirus and backup applications. 9. MS Internet Explorer and Mozilla Firefox are the only two Web browsers supported with the Storage Manager Profiler client application. 10. By default, the Storage Manager Profiler polls all storage subsystems for storage subsystem support data every day at 2:00am. Ensure that there is not heavy usage of the storage subsystem during this time period. This collection time schedule can be modified to start during the window that the storage subsystem has light usage by pointing your Web browser at http://localhost:9000/ and click on the Calendar icon to schedule the data collection frequencies and time. 11. The Storage Manager Profiler typically takes five minutes to seven minutes to collect data, but the time can increase for larger configurations. There have been exceptional instances where storage arrays took up to 20 minutes to capture the data when capturing the drive information. 12. If you have a large system, gathering support data takes longer, and the compressed files are larger. The Storage Manager Profiler compresses the collection data file to be between 2 MB and 5 MB. 13. Monitor each storage subsystem from one Storage Manager Profiler instance. Gathering data from a storage subsystem with multiple Storage Manager Profiler instances can cause problems. No mechanisms exist that prevent multiple Storage Manager Profiler instances from trying to find data from the same storage subsystem. 14. When multiple Storage Manager instances are installed in the environment, do not define the same storage subsystem twice in the Storage Manager Enterprise Management window. 15. The data collection process of the Storage Manager Profiler is multi- threaded with a polling mechanism in place to find the maximum number of storage subsystems at pre-defined timing intervals. The polling mechanism is not sequential. For example, if the upper limit on the number of storage subsystems from which the Storage Manager Profiler can find data is 20, and 60 storage subsystems are defined, 20 threads are gathered immediately, while the data from the remaining 40 storage subsystems are gathered as resources became available. The Storage Manager Profiler supports at least 10 storage subsystems. 16. The Storage Manager Profiler does not support in-band management of storage subsystems. 17. The only function that the Storage Manager Profiler supports is the Support Monitor. 18. A minimum of 06.19.xx.xx controller firmware is required to use the Storage Manager Profiler. 2. The online help of the Command Line Interface commands (SMcli commands) incorrectly showed the parameters of certain SMcli commands. The parameters that were shown incorrectly belong to the "disk" type parameter such as Drive, Drivechannels, DiskDrives, repositoryDrives ... These parameters were incorrectly shown with the additional word "disk" such as diskDrive, DiskDriveChannels, repositoryDiskDrive ... The SMcli command syntax checking engine will display the correct syntax for these parameters. Make the modifications as suggested by the SMcli command syntax checking engine. One can also refer to the pdf copy of the Command Line Interface and Script Commands Programming Guide - IBM System Storage DS4200, DS4700, and DS5000 in the IBM DS support web site for help on the SMcli command syntax. 3. The suggested recovery path in the mis-wired guru event might send the user down either the wrong path or very long path when trying to fix the first mis-wired port. The work-around is to use the cabling diagram in the EXP5060 Installation, User's and Maintenance guide or the DS5100 and DS5300 Installation, User's and Maintenance guide publications to fix the cabling mis-wired error. The pdf version of these pubs are available in the IBM DS support web site. New limitations with Storage Manager version 10.60.xx.11 release (controller firmware 07.60.xx.xx). 1. If port 1 of the iSCSI host interface is disconnected when the iSCSI configuration window is first opened, the status of port 1 shows as connected. If you switch to port 2 and back to port 1, the status will refresh and port 1 will show as disconnected. 2. When modifying the iSCSI host port attributes there can be a delay of up to 3 minutes if the port is inactive. If possible, connect a cable between the iSCSI host port and a switch prior to configuring any parameters. 3. When applying the Premium feature keys to enable the 64 or 112 drive attachment to the DS5020 subsystem, the "drive slot limit" premium feature entry in the Premium Features and Feature Pack Information window will not be updated to reflect the maximum number of drives that can be attached to the subsystem (either 64 or 112). In addition, when trying to attach more drives than the DS5020 is currently allowed, the "drive slot limit" premium feature entry in the Premium Features and Feature Pack Information window will be displayed with the "out of compliance status". To view the maximum number of drives that can be attached to a DS5020, obtain the Storage Subsystem profile and search for the following info. Drive Limit Management: Number of drive slots discovered: 32 Number of drive slots allowed: 112 Note: The controllers use the discovered drive slot in the subsystem configuration number to determine whether the maximum number of drives limit is exceed or not instead of the actual number of drives installed. For example, if there are two drive expansion enclosures attached to the DS5020, the number of discovered drive slot will be 42 which is exceeding the limit of 32 that the DS5020 supported as standard feature even the total number of installed drives actually installed in the subsystem is 32 or less. In this case, the drive slot limit will be shown with the status Out-of-Compliance until the DS5020 33-64 drive attach premium feature key is applied. (XB014946) 4. The Configure iSCSI host port window always displayed the iSCSI host port number with respect to the installed iSCSI port in the subsystem only. It does not take into account of other types of host port installed in the subsystem. Its port counting starts with the first discovered iSCSI port in the subsystem instead of the first host port installed in the subsystem per controller host port scanning order. For example, the DS5020 controller with iSCSI port option will have the port labeled as ports 1 and 2 per controller in the Configure iSCSI host port window instead of as ports 3 and 4 because there are two FC ports installed in the controller boards. However, the MEL entries will refer to the iSCSI posts as ports 3 and 4 instead of as ports 1 and 2 as referred to in the Configure iSCSI host port window. Similarly, in the DS5100 and DS5300 subsystems, the iSCSI host ports in HIC slot 2 will be referred to as ports 1 and 2 in the Configure iSCSI host port window and ports 5 and 6 in the MEL if the FC host card is installed in HIC slot 1. (XB014900) 5. The Premium Feature activation confirmation window for Drive Security (FDE) feature activation key will show the feature as "Unknown capacity". Click Ok to confirm that you want to go ahead with the enablement of the Drive Security (FDE) feature. 6. When doing a Refresh DHCP operation in the Configure iSCSI port window, and the iSCSI port is unable to contact the DHCP server, the following inconsistent informational Mel events can be reported; - MEL 1810 DHCP failure - MEL 1807 IP address failure - MEL 1811 DHCP success. For this error to occur, the following specific conditions and sequence must have been met: - Before enabling DHCP, static addressing was used on the port and that static address is still valid on the network. - The port was able to contact the DCHP server and acquire an address. - Contact with the DHCP server is lost. - The user performs the Refresh DHCP operation from DS Storage Manager Client. - Contact with the DHCP server does not come back during the DHCP refresh operation and timeouts. Check the network connection to your iSCSI port and the status of the DHCP server before attempting the Refresh DHCP operation again. New limitations with Storage Manager Upgrade Utility package version 10.60.xx.05 release (controller firmware 07.60.xx.xx). 1. none New limitations with Storage Manager Upgrade Utility package version 10.50.xx.23 release (controller firmware 07.50.xx.xx). 1. The Storage Manager on-line help contains inaccurate information about locking Encryption Capable drives. The current on-line help states "Use this command to set the new security key to lock all of the Encryption capable drives." The on-line help text should state " Use this command to set the security key that is used throughout the storage subsystem to implement the Disk Encryption premium feature. When any security- capable drive in the storage subsystem is assigned to a secured array, that drive will be security-enabled using the security key." 2. The Storage Manager Re-key operations can fail when there are Encryption Capable drives present in the system that are spun down. When drives are marked for export in a storage subsystem the drives are spun down. Attempting to generate a lock key with spun down drives will fail. Remove the exported drives from the subsystem and retry the operation. 3. When using the SMcli to create an Encryption drive security key, the SMcli command will not save the security key in a default location and a separate location at the same time. The new security key is saved in the location the SMcli was executed from if the command does not include a file location with a fully qualified path. 4. The Storage Manager Controller Firmware upgrade status message can be misleading. The Storage Manager Controller Firmware upgrade screen will report a controller is running an unsupported firmware version if the subsystem is unresponsive at the time of the upgrade. New limitations with Storage Manager Upgrade Utility package version 10.50.xx.19 release (controller firmware 07.50.xx.xx). 1. The DS Storage Manager version 10.50.xx.19 will not manage DS4000 Storage Subsystems with Controller firmware levels prior to v5.40.xx.xx. 2. Start of day (a controller reboot) can take a very long time, up to 20 minutes, after a subsystem clear configuration on a DS5000 subsystem. This occurs on very large configurations, now that the DS5000 can support up to 448 drives, and can be exacerbated if there are SATA drives. 3. Veritas cluster server node failure when fast fail is enabled. Recommend setting dmp_fast_fail HBA flag to OFF. Frequency of this causing a node failure is low unless the storage subsystem is experiencing repeated controller failover conditions. 4. Brocade HBA does not support direct attach to storage subsystem. 5. At times the link is not restored when inserting a drive side cable into a DS5000 controller, a data rate mismatch occurs. Try reseating the cable again to clear the condition. 6. Due to a timing issue with controller firmware, using SMcli or the script engine to create LUNs and set LUN attributes will sometimes end with a script error. 7. Mapping host port identifiers to host via Script Editor hangs; fails via CLI with "... error code 1”. This will occur when using the CLI/script engine to create an initial host port mapping. 8. Under certain high stress conditions controller firmware upgrade will fail when volumes do not get transferred to the alternate controller quick enough. Upgrade controller firmware during maintenance windows or under low stress IO conditions. New limitations with Storage Manager Upgrade Utility package version 10.36.xx.13 release (controller firmware 07.36.xx.xx). 1. None New limitations with Storage Manager Upgrade Utility package version 10.36.xx.07b release (controller firmware 07.36.xx.xx). 1. Upgrade of DS4000 to 7.xx.xx.xx using the upgrade tool with non-English OSes will end with an error. The current firmware column still shows the previous version, pending version will show 7.xx.xx.xx, instead of 'none'. Checking the upgrade tool log you will find: [12.11.2008 08:51:16] [rey-ds4700-1] [SUPPORT_SERVICES] [DownloadAndActivate] activation failed There are two ways to check the content of this log: 1. As long as the upgrade tool is still open: Use the 'View log' button 2. If the upgrade tool was closed already: For windows all logs can be found in this folder: C:\Program Files\IBM_DS4000FirmwareUpgrade\client For other operating systems, check in the appropriate folder. Syntax of the name is similar to 20081114_1501.log. Then check the profile. Here the new firmware can be found as pending: Current configuration: Firmware version: 06.60.17.00 NVSRAM version: N1814D470R916V17.dlp Pending configuration: Staged firmware download supported: Yes Firmware version: 07.36.12.00 NVSRAM version: N1814D47R1036V12.dlp This shows that firmware was loaded to controller but not yet activated. Workaround: After checking the items listed in Details section, activate the loaded firmware using this script command: activate storageSubsystem firmware; Mark the affected system in the Enterprise Management window of the Storage Manager. In the menu, go to Tools -> Execute script. A new window will show up. Paste the command in the upper part of this window and choose Tools -> Execute only. The activation will take a while and the controller will reboot. New limitations with Storage Manager Installer (SMIA) package version 10.36.xx.07 release. 1. With Windows Vista and Windows Server 2008, when you try to write a file using the SMcli command, the command reports that the file has been written, but the file was not written. The SMcli should issue an error code or a statement that the file was not written to the disk. Disable the Use User Account Control (UAC) option, or start the DOS prompt in an administrator mode, which gives you permission to write to the disk. Try to write the file again. New limitations with Storage Manager Installer (SMIA) package version 10.30.xx.09 release. 1. Using VDS/VSS utilities (diskraid and diskpart) to create and map volumes may not immediately see the LUNs listed on the host due to PnP taking time to scan for the devices. Wait for the devices to show up in device manager prior to using diskpart. 2. When writing an SMcli command file, the command reports that the file is written, but you cannot find the file. User Account Control is enabled on the host, and it does not allow you to modify any files on the hard drive without permission. Disable this control, and rerun the SMcli command. 3. If you use a storage array as a boot device for the Windows Server 2003 operating system, you cannot use the hibernation feature. New limitations with Storage Manager Installer (SMIA) package version 10.15.xx.08 release. 1. Reconfiguration operation (DRM) is delayed under some circumstances. When a drive fails before the DRM completes, it can take up to eight times as long for the DRM to complete. DRM reconfigurations to RAID 6 have the longest impact since there are four times as many calculations and writes that have to occur compared to other RAID levels. 2. Host Software display of controller current rate is wrong below 4Gbps. Host Software Client - AMW - Logical/Physical View - Controller Properties - Host Interfaces - Current rate is displaying "Not Available" when the controller negotiated speed is 2Gbps. When the controller negotiated speed is reduced to 1GBs, the Current rate displays "2Gbps" New limitations with Storage Manager Installer (SMIA) package version 10.10.xx.xx release (controller firmware 07.10.xx.xx). 1. Controller Alarm Bell icon does not appear as a flashing icon indicator on the screen to get the user's attention but the icon does change appearances. 2. Miswire of drive tray cabling with DS4700 and DS4200 can cause continuous reboot of a controller. To correct this situation, power down the subsystem, cable the drive trays correctly, and power the subsystem back up. 3. Controller button may appeared enabled and mislead the user that a controller is selected where in fact, a controller was not highlighted for the button to appear ready. 4. Search key is not marked correctly in that page due a JavaHelp Bug with JavaHelp 2.0_01. A search for keyword "profile" ended with phase "prese 'nting p' rofile" being marked. 5. storageArrayProfile.txt should be renamed as storageSubsystemProfile.txt in Support Data. 6. Bullets Incorrectly Placed in Volume Modification Help Page 7. Unable to Escape out of Help Display. User will be required to close the window by using window close procedure (exit, etc.) 8. Bullets and Descriptions not aligned into same line in "Viewing mirror properties". 9. The Help window is not getting refreshed properly when using the AMW.Help window. Workaround is to close and reopen Storage Manager client. 10. CLI command failure for creation of volume(s) if capacity parameter syntax is not specified. A space will need to be used between the integer value and the units used in the capacity option of this command or, "create volume volumeGroup[4] capacity=15 GB…". 11. Customer will see high ITW counts displayed in GUI (RLS feature) and logs (files) for diagnostics (support bundle, DDC, etc.) and may be concerned that he has a problem. This will not cause a Critical MEL event. Known problem previously restricted, when a DS4700 or DS4200 controller reboots, these counters increment. 12. Single tray powercycle during IO activity causes drives in tray to become failed. Customer may see loss of drive (failed) due to timing issue of drive detection & spin-up of the drive. There are one of two conditions that result on power-up: - (Most likely) Drive will be marked as optimal/missing with the piece failed, or - (rarely) Drive will be marked as failed with the piece failed. Workaround is to unfail (revive) drive which restarts reconstruction of all pieces. 13. Event log critical Event 6402 was reported after creating 64 mirror relations. Eventually, the mirror state transitions to synchronizing and proceeds to completion on mirror creation. Workaround is to ignore the MEL logging since this occurs on creation of mirror volumes. 14. Reconfiguration operations during host IO may result in IO errors when arrays contain more than 32 LUNs. These operations include Dynamic Capacity Expansion, Defragmentation, Dynamic Volume Expansion, Dynamic RAID Migration. The workaround is to quiesce host IO activity during reconfiguration. 15. Heavy IO to a narrow volume group of SATA drives can result in host IO timeouts. A narrow volume group refers to an array built of very few drives; namely 1 drive RAID 0, 1x1 RAID 1, and 2 + 1 RAID 5. The workaround is to build arrays of SATA drives out of 4 + 1 or greater. 16. When managing the storage subsystem in-band, the upgrade utility will show the upgrade as failed. This is because of the update and reboot of the controllers when activating the new firmware. SMagent is not dynamic and will need to be restarted to reconnect to the storage subsystem. 17. Selecting and dragging text within the storage profile window causes the window to be continuously refreshed. Work around is to select and copy, do not drag the text. 18. When configuring alerts through the task assistant, the option stays open after selecting OK. The window only closes when the cancel button is selected. 19. The Performance Monitor displays error messages when the storage subsystem is experiencing exception conditions. The performance monitor has a lower execution priority within the controller firmware than responding to system IO and can experience internal timeouts under these conditions. 20. Critical MEL event (6402 - Data on mirrored pair unsynchronized) can occur under certain circumstances with synchronous RVM. The most likely scenario is when both primary and secondary are on a remote mirror and an error occurs with access to that host. Resynchronization should occur automatically, when automatic resynchronization is selected for a mirror relationship. However if any of the host sites should go down during this interval, recovery by the user is required. 21. A persistent miswire condition is erroneously reported through the recovery guru even though the subsystem is properly wired. The frequency of occurrence is low and is associated with an ESM firmware download or other reboot of the ESM. The ESM that is reporting the problem must be reseated to eliminate the false reporting. Not all miswire conditions are erroneous and must be evaluated to determine the nature of the error. 22. Drive path loss of redundancy has been reported during ESM download. This occurs when a drive port is bypassed. In some instances this is persistent until the drive is reconstructed. In other cases it can be recovered through an ESM reboot (second ESM download, ESM pull and replace). 23. Unexpected drive states have been observed during power cycle testing due to internal controller firmware contention when flushing MEL events to disk. The drives have been observed as reconstructing or replaced when they should have been reported as failed. Also volume groups have been reported degraded when all drives were assigned and optimal. An indication that this is the situation would be when drive reconstruction has not completed in the expected amount of time and does not appear to be making any progress. The work around is to reboot the controller owning the volume where the reconstruction has stalled. 24. Sometimes when an ESM is inserted a drive's fault line is asserted briefly. The fault line almost immediately returns to inactive, but the ESMs may bypass the drive. In these circumstances, the administrator will have to reconstruct the failed drive. 25. After a drive fail, a manually initiated copyback to a global hot spare may also fail. The work around is to remove the failed drive and reinsert it, then the copyback should resume and complete successfully. 26. When an erronieous miswire condition occurs (as mentioned above in 21), the recovery guru reports the miswire on one controller but not on the other. In this situation, ignore the other controller and use the information supplied by the controller reporting the problem. 27. Occasionally a controller firmware upgrade to 07.10 will unexpectedly reboot a controller an extra time. This could generate a diagnostic data capture, however the firmware upgrade is always successful. 28. When managing previous releases of firmware (06.19 and prior), "working" gets displayed as "worki" during volume creation. 29. The Performance Monitor error window does not come to the front. You must minimize all other foreground windows to get to the error popup window. 30. When a disk array is in a degraded state, the array will report "needs attention" to both the EMW and the AMW. After taking appropriate corrective action, the AMW view of the array will report "fixing" but the EMW state remains at "needs attention". Both statuses are valid, when the fault state is resolved both views will change to "optimal". 31. Storage subsystem loses in-band connectivity during volume creation. This is caused by the controller logout to all hosts that are in the default host group when those hosts have QLogic HBAs which is not tolerant of the controller initiated logout. The work around is to first create the host group and host port mappings prior to creation of volumes. Then on volume creation avoid using the default host group. 32. When defining additional LUN mappings to a host, the volume name moves down to the bottom of the visible list making it difficult to keep track of the list. 33. A Windows server will experience a Blue Screen and will need to be rebooted when one or more controllers go offline in a storage subsystem. A LUN/path may be in the process of being removed because an HBA has not reestablished a login with the controller and the PnP process will remove all LUNs associated with that path. The timing of this should not be seen unless the customer is experiencing major problems with controllers going into offline states. 34. With SMProvider installed, the disk management on the server does not complete within 1 hour for a configuration of 20 or more storage subsystems attached on the subnet. This is an issue with the auto- discovery of storage IP addresses by the SMProvider that supports the VDS/VSS feature of Windows. On installation of the SMProvider, add all of the IP addresses for the storage subsystems into the registry. On reboot, the registry contains the list of IP addresses and avoids the auto-discovery delay. The registry location is: HKEY_LOCAL_MACHINE\SOFTWARE\Storage\SMprovider /v IpAddresses /t REG_SZ /d If the value is empty, the providers will use the auto-discovery method. 35. Result of an installation not completing normally because of a crash, blue screen, or other interruption will prevent the SMclient from being able to uninstall. This is because the InstallAnywhere program writes to the ZeroG registry file at the very end of the installation process. Reinstall the package to overwrite the installation and populate the ZeroG registry. 36. Using ALT-Q to access the QLogic HBA BIOS will hang the host, use CTL-Q instead. 37. Intermittently the flashcopy utility using the VSS provider fails to create persistent flashcopies. The flashcopy volume is created at the storage subsystem and the volume mappings complete successfully, but after about one minute the vshadow utility removes the volume because Microsoft's PnP driver does not detect the flashcopy volume in time. If a flashcopy failure has occurred, or the limit on flashcopies has been reached, remove any unnecessary flashcopies on the storage subsystem and retry the failed flashcopy request. Please note that some utilities such as NetBackup do not automatically clean up the failed request by removing these failed flashcopies from the storage array. 38. Startup of MS DISKRAID utility executing through VDS occasionally reports an error. The following message is reported: "Diskraid encountered a fatal error while initializing. The following information may help diagnose the error: Error: 0x80080005 Location Code: 2" The server must be rebooted to recover, shutdown and restart of the VSS/VDS service does not fix the problem. 39. Configuring separate Email alerts when two Enterprise management windows are open on the same host will cause the alerts to disappear if one of the Enterprise windows is shut down and then restarted. It is recommended that if multiple Enterprise management windows needs to be open, that they are open on separate Hosts which will indeed allow the configuration of alerts to be saved if one of the enterprise management windows is shut down and restarted. 40. DVE (Dynamic Volume expansion) is not possible on a volume which is in an active mirror relationship and which write-mode is 'Asynchronous not write-consistent'.The DVE is not possible on either the primary or the secondary volume. The DVE is possible, if the write-mode is 'Synchronous' or 'Asynchronous write-consistent'. The DVE is also not possible on a FlashCopy Repository of the secondary volume. The attribute of the write- mode on the primary volume which is mirrored to the secondary, is given to the FlashCopy Repository Volume of the secondary's FlashCopy Volume. A workaround is to set the write-mode of the mirrored primary volume from 'Asynchronous not write-consistent', to 'Asynchronous write-consistent' or 'Synchronous', to run DVE and when DVE is finished to re-set the write-mode to 'Asynchronous not write-consistent'. Legacy restrictions that are still applicable: 1. Reflected Fibre Channel (FC) OPN frames occurs when intermixing the EXP810, EXP710 and EXP100s behind DS4700 or DS4800 storage subsystems. This behavior causes excessive drive side timeout, drive side link down and drive side link up events be posted in the DS4000 storage subsystem Event log (MEL.) It might also cause drives to be by-passed or failed by the controller. NEW DRIVE SIDE FC CABLING REQUIREMENT MUST BE ADHERED TO WHEN HAVING EXP100 CONNECTED TO THE DS4700 OR DS4800 STORAGE SUBSYSTEMS. Please refer to the latest version of the Installation, User's and Maintenance Guide for these storage subsystems that are posted in the IBM DS4000 Support web site for more information. http://www.ibm.com/systems/support/storage/disk 2. Can not increase the capacity of RAID arrays. RAID arrays with certain combinations of selected segment size and number of drives that made up the arrays will exceed the available working space in controller dacstore, causing a reconfiguration request (like expanding the capacity of the array) to be denied. These combinations are generally the largest segment size (512KB) with the number of drives in the array is 15 drives or more. There is no work-around. C324144 105008 3. Interoperability problem between the Tachyon DX2 chip in the DS4500 and the DS4300 storage subsystem controllers and the Emulex SOC 422 chip in the EXP810 expansion enclosure ESMs causing up to 5 Fibre Channel loop type errors to be posted in the DS4000 storage subsystem Major Event Log during a 24 hour period. There is a small window in the SOC 422 chip that multiple devices can be opened at one time. This ultimately leads to Fibre Channel loop errors of Fibre Channel link up/down, Drive returned CHECK CONDITION, and Timeout on drive side of controller. IBM recommends the use of the Read-Link-Status function to monitor drive loop for any problems in the drive loop/channel. There is no work-around. 4. The single digit of the Enclosure IDs for all enclosures (including the DS4000 storage subsystem with internal drive slots) in a given redundant drive loop/channel pair must be unique. For example, with four enclosures attached to the DS4300, the correct enclosure ID settings should be x1, x2, x3, and x4 (where x can be any digit that can be set). Examples of incorrect settings would be 11, 21, 31, and 41 or 12, 22, 32, and 62. These examples are incorrect because the x1 digits are the same in all enclosure IDs (either 1 or 2). If you do not set the single digit of the enclosure IDs to be unique among enclosures in a redundant drive loop/channel pair, then drive loop/channel errors might be randomly posted in the DS4000 subsystem Major Event Log (MEL), especially in the cases where the DS4300 storage subsystems are connected to EXP810s and EXP100s. In addition, enclosure IDs with same single digits in a redundant drive loop/channel pair will cause the DS4000 subsystem controller to assign a soft AL_PA address to devices in the redundant drive loop/channel pair. The problem with soft AL_PA addressing is that AL_PA address assignment can change between LIPs. This possibility increases the difficulty of troubleshooting drive loop problems because it is difficult to ascertain whether the same device with a different address or a different device might be causing a problem. 5. In DS4000 storage subsystem configurations with controller firmware 6.15.2x.xx and higher installed, the performance of write intense workloads such as sequential Tape restores to DS4000 Logical drives with large I/O request sizes (e.g. 256kB) is degraded if the DS4000 logical drives are created with small segment sizes such as 8KB or 16KB. The work around is to create the DS4000 logical drives with segment size of 64KB or higher. 6. Do not pull or insert drives during the drive firmware download. In addition, ALL I/Os must also be stopped during the drive firmware download. Otherwise, drives may be shown as missing, unavailable or failed. 7. Do not perform other storage management tasks, such as creating or deleting logical drives, reconstructing arrays, and so on, while downloading the DS4000 storage subsystem controller firmware and DS4000 EXP ESM firmware. It is recommended that you close all storage management sessions (other than the session that you use to upgrade the firmware) to the DS4000 storage subsystem that you plan to update. 8. For Microsoft Windows Server 2003 R2 operating systems. When loading the Microsoft Hot fix KB916048, required in installing Storage Manager, if the IBM xSeries Server hangs during reboot it may be resolved by using the latest Broadcom driver for the Broadcom HT1000.