Performance data files: QAPMDISKINTNUMInterval number: The nth sample database interval based on the start time specified in the Create Performance Data (CRTPFRDTA) command.PD (5,0)DTETIMInterval date (yymmdd) and time (hhmmss): The date and time of the sample interval.C (12)INTSECElapsed interval seconds: The number of seconds since the last sample interval.PD (7,0)IOPRNIOP resource nameC (10)DIOPIDReservedC (1)DSARMDisk arm number: Specifies the unique identifier of the unit. Each actuator arm on the disk drives available to the machine represents a unit of auxiliary storage. The value of the unit number is assigned by the system when the unit is allocated to an ASP.C (4)DSTYPEDisk drive type such as 9332, 9335, or 6100.C (4)DSDRNDevice resource name. Typically, there is one disk (device) resource per disk unit except for a multipath disk unit that has multiple disk resources associated with it (see note 5).C (10)DSSCANNumber of search string commands: This count is always zero, because search string commands are not supported for the 9332, 9335, or 6100.PD (5,0)DSBLKR Number of blocks read: Block is one sector on the disk drive.PD (11,0)DSBLKW Number of blocks written: Block is one sector on the disk drive. PD (11,0)DSBLKRNumber of blocks read: The block length is 520 bytes, which includes 8 bytes of system control information.PD (11,0)DSBLKWNumber of blocks written: The block length is 520 bytes, which includes 8 bytes of system control information.PD (11,0)DSIDLCProcessor idle loop counter (see note 1): The number of times the disk controller passed through the idle loop. This count is increased differently for the 9332 and the 9335. For the 9332, this counter is increased only if the disk controller is totally idle (for example, no I/O operations are active.) For the 9335, even though the disk controller may be idle and the counter gets increased, an I/O operation can be active (for example, seek is being performed.) This field is nonzero for drive types that support a dedicated disk processor and zero for other drive types.

DSIDLC and DSIDLT are duplicated across all arms for the same disk controller.

PD (11,0)DSIDLTProcessor idle loop time (see note 3): The time (in hundredths of microseconds) to make one pass through the idle loop. This field is nonzero for drive types that support a dedicated disk processor and zero for other drive types. The value reported could be a multiple of the actual idle loop time. In that case, the value reported for the processor idle loop count field (DSIDLC) is reduced accordingly so that the calculated processor utilization is correct.

DSIDLC and DSIDLT are duplicated across all arms for the same disk controller.

PD (11,0)DSSK1Number of seeks > 2/3: The number of times the arm traveled more than 2/3 of the disk on a seek.PD (11,0)DSSK2Number of seeks > 1/3 and < 2/3 (see note 2): The number of times the arm traveled more than 1/3 but less than 2/3 of the disk on a seek.PD (11,0)DSSK3Number of seeks > 1/6 and < 1/3 (see note 2): The number of times the arm traveled more than 1/6 but less than 1/3 of the disk on a seek.PD (11,0)DSSK4Number of seeks > 1/12 and < 1/6 (see note 2): The number of times the arm traveled more than 1/12 but less than 1/6 of the disk on a seek.PD (11,0)DSSK5Number of seeks < 1/12 (see note 2): The number of times the arm traveled from its current position but less than 1/12 of the disk on a seek.PD (11,0)DSSK6Number of zero seeks (see note 2): The number of times the access arm did not physically move on a seek request. The operation may have resulted in a head switch. This field is 0 for disk drive type 6100. The number of zero seeks will be accumulated in DSSK5.PD (11,0)DSQUELTotal queue elements: The number of I/O operations waiting service at sample time. This number includes the I/O operation that is in progress. Divide this by DSSMPL to get the average queue length.PD (11,0)DSNBSYNumber of times arm not busy: The number of times there were no outstanding I/O operations active at sample time.PD (11,0)DSSMPL Number of samples taken: The number of samples taken for the DSQUEL and DSNBSY fields. PD (11,0)DSCAPDrive capacity (in bytes): Total number of bytes of auxiliary storage provided on the unit for the storage of objects and internal machine functions when the ASP containing it is not under checksum protection. The unit reserved system space value is subtracted from the unit capacity to calculate this capacity.PD (15,0)DSAVLDrive available space (in bytes): Total number of bytes of auxiliary storage space that is not currently assigned to objects or internal machine functions, and therefore is available on the unit.PD (15,0)DSASPASP number: Specifies the ASP to which this unit is currently allocated. A value of 1 specifies the system ASP. A value from 2 through 32 specifies a basic ASP. A value from 33 to 255 specifies an independent ASP. A value of 0 indicates that this unit is currently not allocated.PD (5,0)DSCSSReservedC (2)DSPCAPReservedPD (11,0)DSPAVLReservedPD (11,0)DMFLAG' ' means this arm is not locally mirrored. 'A' means this is the designated first arm of a locally mirrored pair. 'B' means this is the designated second arm of a locally mirrored pair.C (1)DMSTSLocal mirroring status. 1 = active, 2 = resuming, 3 = suspendedPD (1,0)DMIRNLocally mirrored IOP resource nameC (10)DMDRNLocally mirrored device resource nameC (10)DSRDSNumber of read data commands.PD (11,0)DSWRTSNumber of write data commands.PD (11,0)DSBUFONumber of buffer overruns: The number of times that data was available to be read into the disk controller buffer from the disk, but the disk controller buffer still contained valid data that was not retrieved by the storage device controller. Consequently, the disk had to take an additional revolution until the buffer was available to accept data. This field is 0 for disk drive type 6100.PD (11,0)DSBUFUNumber of buffer underruns: The number of times that the disk controller was ready to transfer data to the disk on a write, but the disk controller buffer was empty. The data was not transferred in time by the disk IOP to the disk controller buffer. The disk was forced to take an extra revolution awaiting the data. This field is 0 for disk drive type 6100.PD (11,0)DSMDLNModel Number: The model number of the disk drive.C (4)DSDCRHDevice cache read hits: The number of times that all of the data requested by the read operation was obtained from the device read or write cache.PD (11,0)DSDCPHDevice cache partial read hits: The number of times that a portion, but not all, of the data requested by the read operation was obtained by the device read or write cache. A physical operation to the device media was required to obtain the remaining data.PD (11,0)DSDCWHDevice cache write hits: The number of times that the data associated with a write operation replaces, or is combined with, existing data in the device write cache, thereby eliminating a write operation.PD (11,0)DSDCFWDevice cache fast writers: The number of times that space was available in the device write cache for the data associated with a write operation and a response was returned immediately.PD (11,0)DSDROPDevice read operations: The number of read operations issued to the device by the controller. This includes operations generated for redundant system data areas. It does not include operations generated for diagnostics or access to the controller reserved area that occur during this idle time.PD (11,0)DSDWOPDevice write operations: The number of write operations issued to the device by the controller. This includes operations generated for redundant system data areas. It does not include operations generated for diagnostics or access to the controller reserved area that occur during this idle time.PD (11,0)DSCCRHController cache read hits: The number of times that all of the data requested by the read operation was obtained from the controller read or write cache.PD (11,0)DSPCPHController cache partial read hits: The number of times that a portion of the data requested by the read operation was obtained from the controller read and write cache. An operation to the device was required to obtain the remaining data.PD (11,0)DSCCWHController cache writes hits: The number of times that the data associated with the write operation replaces or is combined with existing data in the controller write cache. This eliminates a write operation.PD (11,0)DSCCFWController cache fast writes: The number of times that space was available in the controller write cache for the data associated with a write operation and a response was returned immediately.PD (11,0)DSCOMPCompressed Unit indicator. '0' if disk data is not compressed and '1' if disk data is compressed.C (1)DSPBUPhysical blocks used. For compressed units, this field contains the total number of physical blocks used (written) in the device user data area. For non-compressed units, this field contains 0.PD (11,0)DSPBAPhysical blocks allocated. For compressed units, this field contains the total number of physical blocks committed (reserved) in the device user data area for DASD extents. This value includes all of the Physical Blocks Used. For non-compressed units, this field contains 0.PD (11,0)DSLBWLogical blocks written. For compressed units, this field contains the total number of logical blocks written in the device user data area. This value represents the total amount of data written to allocated extents. For non-compressed units, this field contains 0.PD (11,0)DSLBALogical blocks allocated. For compressed units, this field contains the total number of logical blocks contained in allocated compression groups. This value represents the total sum of all allocated compression groups in the device user data area. For non-compressed units, this field contains 0.PD (11,0)DSPBCOPhysical blocks for compression overhead. For compressed units, this field contains the total number of physical blocks that are used for compression directory structures and reserved areas that are unavailable for storing user data. For non-compressed units, this field contains 0.PD (11,0)DSFGDRForeground directory reads. For compressed units, this field is the number of device read operations that have been performed to read directory structures required to complete host system commands. For non-compressed units, this field contains 0.PD (11,0)DSFGDWForeground directory writes. For compressed units this is the number of device write operations that have been performed to write directory structures required to complete host system commands. For non-compressed units, this field contains 0.PD (11,0)DSBGDRBackground directory reads. For compressed units, this is the number of device read operations that have been performed in the management of compression directory structures, but were not immediately required to complete host system commands. For non-compressed units, this field contains 0.PD (11,0)DSBGDWBackground directory writes. For compressed units, this is the number of device write operations. For non-compressed units, this field contains 0.PD (11,0)DSFGREForeground read exceptions. For compressed units, this is the number of times an additional device read operation was issued to read data that had been stored in the exception area on a compressed device (this count applies only to multi-page operations). This count reflects only those operations immediately required to complete host system commands.PD (11,0)DSFGWEForeground write exceptions. For compressed units, this field is the number of times an additional device write operation was issued to write data into the exception area on a compressed device (this count applies only to multi-page operations). This count reflects only those operations immediately required to complete host system commands. For non-compressed units, this field contains 0.PD (11,0)DSFGSForeground sweeps. For compressed units, a sweep is the process used to store a 1-MB compression group in the correct number of sectors so there are no unused areas in the data region and no used areas in the exception region of the compression group. The number of foreground sweeps is the number of times an entire 1-MB compression group was required to be swept to complete host system commands. The sweep is needed because the data for a host system write operation does not fit into the physical space reserved. The new data does not compress as well as the data that was previously in the space. For non-compressed units, this field contains 0.PD (11,0)DSBGSBackground sweeps. For compressed units, a sweep is the process used to store a 1-MB compression group in the correct number of sectors so there are no unused areas in the data region and no used areas in the exception region of the compression group. The number of background sweeps is the number of times an entire 1-MB compression group was swept to maintain the compressed data storage efficiency. This count reflects only those sweeps that were not immediately required to complete host system commands. Background sweeps are intended to increase performance or increase usable capacity of drive. For non-compressed units, this field contains 0.PD (11,0)DSCERCController simulated read cache hits: The number of times that all of the data requested by the read operation could have been, but was not, obtained from a controller read cache (not the controller write cache). This field is updated only when Extended Adaptive Cache Simulator is enabled.PD (11,0)DSASPNASP resource name. Specifies the resource name of the ASP to which this unit is currently allocated. A value of blanks specifies the system ASP or a basic ASP.C (10)DSPSParity set. The valid value for this field is '1' or '0'. The value of this field is '1' when the disk unit is in a parity set; otherwise, it is '0'.C (1)DSHAPSHigh availability parity set. The valid value for this field is '1' or '0'. The value of this field is '1' when the disk unit is in a high availability parity set; otherwise, it is '0'.C (1)DSMUMultipath unit. The valid value for this field is '1' or '0'. The value of this field is '1' when the disk resource represents a multipath disk unit (see note 5); otherwise, it is '0'.C (1)DSIPInitial path of multipath unit. The valid value for this field is '1' or '0'. The value of this field is '1' when the disk resource represents the initial path of a multipath disk unit; otherwise it is '0'. The initial path is the first path observed by the system. It can change after restarting the system (IPL). The resource name of the initial path can be used for reporting a multipath disk unit under a single resource name.C (1)DSPCProduction copy of remotely mirrored independent ASP. The valid value for this field is '1' or '0'. The value of this field is '1' when the disk unit is in a production copy of a remotely mirrored independent ASP; otherwise, it is '0'.C (1)DSMCMirror copy of remotely mirrored independent ASP. The valid value for this field is '1' or '0'. The value of this field is '1' when the disk unit is in a mirror copy of a remotely mirrored independent ASP; otherwise, it is '0'.C (1)DSRDT RAID type: type of RAID parity set for this disk unit. The valid value for this field is '1' or '0'. This field only has meaning for disk units in a parity set (DSPS field set to '1'). '0' = RAID 5 parity set, '1' = RAID 6 parity set.C (1) DSIOPF Managed by IOP (See note 6). The valid value for this field is '1' or '0'. The value of this field is '1' when this disk unit is attached to the disk storage adapter which is managed by IOP; otherwise, it is '0'.C (1) DSCAT Disk unit category. This field indicates if this disk unit has some special characteristics, which may require a special interpretation of its performance data. This can also be determined by examining device type and model for this disk unit. X’00’ = no special category applies, X’01’ = this disk unit is located in external storage media. C (1)
Field Name Description Attribute