HP XP20000/XP24000 HP StorageWorks XP Disk Array Configuration Guide (T5278-96 - Page 92

Table 20 Max throttle (queue depth) requirements for the devices (Solaris) Queue depth option Option 1 Requirements XP10000, XP12000, SVS 200: Queue_depth default. 1024 XP20000, XP24000: Queue_depth 2048 default. CAUTION: The number of issued commands must be completely controlled. Because queuing capacity of the disk array is either 1024 or 2048 per port (depending on the disk array), you must adjust the number of issued commands from Solaris system to less than 1024 or 2048. Otherwise, memory allocate failed messages may occur on the Solaris system, and all read/write I/O may stop, causing the system to hang. Option 2 (preferred) XP10000, XP12000, SVS 200: Number of LUs x queue_depth 1024 and queue_depth 32 XP20000, XP24000: Number of LUs x queue_depth 2048 and queue_depth 32 NOTE: You can adjust the queue depth for the devices later as needed (within the specified range) to optimize the I/O performance. The required I/O time-out value (TOV) for devices is 60 seconds (default TOV=60). If the I/O TOV has been changed from the default, change it back to 60 seconds by editing the sd_io_time or ssd_io_time parameter in the /etc/system file. You may also need to set several other parameters (such as FC fibre support). See the user documentation that came with your FCA to determine whether other options are necessary to meet your operational requirements. NOTE: Use the same settings and device parameters for all systems. For Fibre Channel, the settings in the system file apply to the entire system, not to just the FCAs. To set the I/O TOV and queue depth for the devices: 1. Make a backup of the /etc/system file: cp /etc/system /etc/system.old. 2. To assure you use the default TOV, make sure that no sd_io_time values are set in the /etc/system file or modify the /etc/system file to show the following values: set sd:sd_io_time=0x3c set ssd:ssd_io_time=0x3c for Oracle generic FCA 3. To set the queue depth, add the following to the /etc/system file: set sd:sd_max_throttle = x set ssd:ssd_max_throttle = x for Oracle generic FCA (for x value, see Table 20 (page 92)) Example: set sd:sd_max_throttle = 16 set ssd:ssd_max_throttle = 16