Monitor sbspaces

One of the most important areas to monitor in an sbspace is the metadata page use. When you create an sbspace, you specify the size of the metadata area. Also, any time that you add a chunk to the sbspace, you can specify that metadata space be added to the chunk.

If you attempt to insert a new smart large object, but no metadata space is available, you receive an error. The administrator must monitor metadata space availability to prevent this situation from occurring.

Use the following commands to monitor sbspaces.

Command Description
onstat -g smb s Displays the storage attributes for all sbspaces in the system:
  • sbspace name, flags, owner
  • Logging status
  • Average smart-large-object size
  • First extent size, next extent size, and minimum extent size
  • Maximum I/O access time
  • Lock mode
onstat -g smb c Displays the following information for each sbspace chunk:
  • Chunk number and sbspace name
  • Chunk size and path name
  • Total user data pages and free user data pages
  • Location and number of pages in each user-data and metadata areas
oncheck -ce oncheck -pe Displays the following information about sbspace use:
  • Names of the tables that store smart-large-object data, by chunk
  • Number of disk pages (not sbpages) used, by table
  • Number of free user-data pages that remain, by chunk
  • Number of reserved user-data pages that remain, by chunk
  • Number of metadata pages used, by chunk
The output provides the following totals:
  • Total number of used pages for all user-data areas and metadata area. The system adds 53 pages for the reserved area to the totals for the user-data area and metadata area.
  • Number of free pages that remain in the metadata area
  • Number of free pages that remain in all user-data areas
onstat -d Displays the following information about the chunks in each sbspace:
  • Number of free sbpages in each sbspace chunk, in the metadata area, and in the user-data areas
  • Total number of sbpages in each sbspace chunk, in the metadata area, and in the user-data areas
oncheck -cs oncheck -ps Validates and displays information about the metadata areas for sbspaces..
oncheck -cS Displays information about smart-large-object extents and user-data areas for sbspaces.
oncheck -pS Displays information about smart-large-object extents, user-data areas, and metadata areas for sbspaces. For more information about oncheck -cS and -pS, see managing sbspaces in the topics on table performance considerations in your Informix® Performance Guide.