APAR status
Closed as program error.
Error description
New option in HSM for Windows to control the number of concurrent recall threads Problem Description: When an application is accessing a migrated file through a CIFS share, a system thread is utilized on the file server to send back the file content to the CIFS client. The system thread is blocked until the file is recalled by the HSM Recall service. Depending on the number of concurrent recalls and the time needed to recall each file, several system threads may be blocked at a time. Additionally, more than one system thread may wait for the same file, if multiple requests recalling the same file are issued. However the number of system threads is limited and depends on the operating system configuration and hardware. The file server might become unresponsive with a high number of blocked system threads until some or all files are recalled and the system threads are unblocked. Affected Products: HSM for Windows 5.5.x.x, 5.4.x.x, 6.1.0.0 - 6.1.5.0 (inclusive), 6.3.0.0 - 6.3.0.1 (inclusive) Customer/L2 diagnostics (if applicable): No errors are reported by HSM for Windows, but file server is unresponsive for some period of time. Cluster environments may initiate failovers. Additional Keywords: HSM for Windows, Cluster failover Initial Impact: File server is hanging
Local fix
Increase the number of Windows system threads. Increase recall performance, e.g. by using more tape drives or using disk storage. Find out why that many recalls are initiated at once, reduce the number of concurrent recalls if possible. You can set HSM for windows recall option ConcurrentRecallLimit, IC72637 (NEW HSM FOR WINDOWS RECALL OPTION CONCURRENTRECALLLIMIT) available in version 6.1.4.2 and later versions.
Problem summary
**************************************************************** * USERS AFFECTED: TSM HSM for Windows Client Versions * * 5.4.x.x, 5.5.x.x and 6.1.0.0 to 6.1.5.0 (inclusive), * * 6.3.0.0 - 6.3.0.1 (inclusive) * * * **************************************************************** * PROBLEM DESCRIPTION: * * See ERROR DESCRIPTION * **************************************************************** * RECOMMENDATION: Apply fixing level when available. * * The new options are not available for versions 5.4.x.x and * * 5.5.x.x. * ****************************************************************
Problem conclusion
PROBLEM CONCLUSION The new option ConcurrentThreadLimit has been implemented to control the maximum number of concurrently recalling Windows system threads. During recalls Windows system threads are blocked. Because the number of system threads is fixed the Windows system may become unresponsive. If a new recall request is initiated such that the number of concurrently recalling system threads exceeds the value of ConcurrentThreadLimit, the HSM for Windows filter driver will not initiate the recall of the file, but immediately return the recall request with an error. The error code can be configured with the option ConcurrentThreadLimitCode. The return code received by the application is the only indication that the ConcurrentThreadLimit might have been exceeded. No errors are logged by HSM for Windows. The value for ConcurrentThreadLimit applies to the total of all concurrently recalling system threads regardless of whether they were triggered through CIFS access or local file system access. This option is different from the configurable amount of concurrent connections of the HSM recall service (see http://publib.boulder.ibm.com/infocenter/tsminfo/v6/topic/com. ibm.itsm.hsmwin.doc/c_recall_stngs.html). This option is different from HSM for Windows recall option ConcurrentRecallLimit IC72637 (NEW HSM FOR WINDOWS RECALL OPTION CONCURRENTRECALLLIMIT), as one recall may block several Windows system threads waiting for the same stub file being recalled. In order to activate the concurrent thread limit the administrator has to manually create one DWORD value in the Windows registry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ithsmdrv \Parameters : Name: ConcurrentThreadLimit Type: REG_DWORD Value: Maximum number of allowed concurrent recall threads. The minimum value is "1" and the maximum value is 0x7FFFFFFF. If the option is not set, the maximum value is used. Every concurrent recall thread request exceeding this number is immediately returned with an error. The error code returned is by default 0xC0000267 (STATUS_FILE_IS_OFFLINE). The system administrator can optionally change the error code by manually creating this DWORD value in the Windows registry at the same location: Name: ConcurrentThreadLimitCode Type: REG_DWORD Value: Error code returned to the application when ConcurrentThreadLimit is exceeded. If the option is not set, the default value of 0xC0000267 (STATUS_FILE_IS_OFFLINE) is returned. Consult with your Microsoft Windows system administrators or Microsoft Windows technical support before changing this value. After setting or changing any of these values the system must be rebooted in order to apply the changes. When the HSM file system filter driver recognizes and applies the registry value ConcurrentThreadLimit during boot time it reports feedback by writing the registry key ConcurrentThreadLimitStamp under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ithsmdrv \Parameters : Name: ConcurrentThreadLimitStamp Type: REG_SZ Value: UTC date and time, maximum number of concurrent threads, return code for recalls that are denied due to the concurrent threads limit. (Sample: "12-06-18 08:33:42.062: 16, 0xc0000267"). If the HSM administrator or supporter recognizes this registry key he can be sure that the registry was configured correctly. Note: File access errors can occur for any number of reasons. It is possible for applications to receive 0xC0000267 for reasons other than exceeding the ConcurrentThreadLimit. It is also possible for applications to receive other file access return codes unrelated to ConcurrentThreadLimit. The error message presented to the user depends on how the application handles the error code to an error message. These options should not be applied or changed without thorough testing. The behavior of the applications receiving errors cannot be predicted nor controlled by HSM for Windows. HSM for Windows is not responsible for any application or operating system malfunction as result of applying these options.
Temporary fix
See LOCAL FIX
Comments
APAR Information
APAR number
IC84946
Reported component name
TSM HSM FOR WIN
Reported component ID
5698ICNCL
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-06-28
Closed date
2012-06-29
Last modified date
2012-06-29
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
TSM HSM FOR WIN
Fixed component ID
5698ICNCL
Applicable component levels
R610 PSY
UP
R630 PSY
UP
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Document Information
Modified date:
29 June 2012