System Health Services

For the most important system resources, the IBM® i operating system automatically tracks the highest consumption and consumers.

The IBM i operating system is comprised of many products and components. As an integrated operating system, not only do the products and components frequently rely upon each other, but common building blocks and resources are used. Some of the resources are deemed to be critical because their proper use and consumption is directly related to achieving continued, normal operational behavior. The repository for this tracking lies within Db2® for i.

A table, a view, and global variables combine to provide information about limits on your system. Information about the important limits is logged in a Db2 for i supplied table named QSYS2.SYSLIMTBL. The QSYS2.SYSLIMITS view uses SYSLIMTBL and other Db2 resources to provide extended and formatted detail about these limits. You should generally work with the view rather than the underlying table. You can use Db2 for i provided global variables to control the number of rows kept for each type of limit in SYSLIMTBL.

The following tables list the limits that are tracked along with the corresponding limit ID, the system maximum value, the value that will cause the first row to be added to SYSLIMTBL (the floor), and the amount of change after this first row is written that causes subsequent rows to be added to the table (the increment).
Table 1. Database limits
Limit description Limit ID Maximum Floor Increment
Maximum number of all rows in a partition 15000 4,294,967,288 100,000 500,000
Maximum number of valid rows in a partition 15001 4,294,967,288 100,000 500,000
Maximum number of deleted rows in a partition 15002 4,294,967,288 10,000 100,000
Start of changeMaximum size of a tableEnd of change Start of change15003End of change Start of change1,869,169,767,219End of change Start of change536,865,792End of change Start of change1,073,731,584End of change
Maximum number of overflow rows in a partition 15004 4,294,967,288 10,000 100,000
Maximum number of variable-length segments 15104 65,533 100 100
Maximum number of indexes over a partition 15106 15,000 20 100
Maximum size of a *MAX4GB index 15400 4,294,967,296 838,860,800 167,772,160
Maximum size of a *MAX1TB index 15401 1,869,166,411,776 8,388,608,000 8,388,608,000
Maximum size of an encoded vector index 15403 2,199,023,255,552 1,677,721,600 8,388,608,000
Maximum number of members in a source physical file 16100 32,767 100 50
Maximum number of rows locked in a unit of work 16200 500,000,000 10,000 100,000
Maximum number of row change operations in a unit of work 16201 storage 10,000 100,000
Maximum size of an extended dynamic package 16806 1,056,964,608 335,544,320 8,388,608
Table 2. Journal limits
Limit description Limit ID Maximum Floor Increment
Maximum size of a journal receiver 18300 1,099,511,627,776 10,000,000,000 50,000,000,000
Maximum number of objects that can be associated with a *MAX10M journal 18301 10,000,000 10,000 200,000
Maximum number of objects that can be associated with a *MAX250K journal 18302 250,000 10,000 50,000
Maximum sequence number of a *MAXOPT3 journal 18303
18,446,744,073
,709,551,600
 10,000,000 100,000,000
Maximum sequence number of a *MAXOPT1 or *MAXOPT2 journal 18304 9,999,999,999 10,000,000 10,000,000
Table 3. File system limits
Limit description Limit ID Maximum Floor Increment
Maximum number of object description entries in a library 18400 1,000,000 1,000 1,000
Number of objects linked in a directory 18402 storage 100,000 10,000
Maximum number of directories linked in a directory 18403 1,000,000 1,000 1,000
Maximum number of file system objects in *SYSBAS ASPs 18404 2,147,483,647 100,000 10,000
Maximum number of file system objects in an independent ASP 18405 2,147,483,647 100,000 10,000
Maximum number of document library objects in a folder 18406 65510 1,000 500
Number of document library objects in the system ASP 18407 storage 100,000 10,000
Maximum number of document library objects in a user ASP 18408 1,000,000 100,000 10,000
Maximum number of bytes in a stream file 18409 1,099,511,627,776 16,777,216 1,048,576
Maximum number of bytes in a document 18410 2,147,483,647 16,777,216 1,048,576
Table 4. Work management limits
Limit description Limit ID Maximum Floor Increment
Maximum number of jobs 19000 970,000 1,000 400
Maximum number of spool files 19002 2,610,000 10,000 5,000
Maximum number of spooled files in each independent ASP 19003 10,000,000 10,000 5,000