The nzds command
Use the nzds command to manage and obtain information about the data slices in the system.
Syntax
nzds [-h|-rev] [-hc] subcmd [subcmd_options]
Inputs
Input | Description |
---|---|
nzds show [options] | Displays information about the data slice topology. The show subcommand
is the default and displays a list of all the data slices on the system
and information about status, the SPU that manages the data slice,
the Primary Storage (that is, the disk ID where the primary copy of
the data slice resides), the Mirror Storage (that is, the disk ID
where the mirror copy of the data slice resides), and % Used (the
amount of space in the data slice that contains data). You can specify one or more options to show specific output. |
nzds show [-detail] | Displays information about the data slice topology and includes information about locations and disk space. |
nzds show -spa id | Displays information about the data slices which are owned by a particular S-Blade in the SPA. |
nzds show -dsId id | Displays information about the specific data slice. |
nzds show -id hwId | Displays information about the data slices that are assigned to the specified hardware. |
nzds show -topology | Displays the current storage topology. The output shows how system resources such as SPUs, disks, SAS switches, and HBA ports are used within the system to support the storage paths. This command is not supported on IBM® Netezza® High Capacity Appliance C1000 systems or on Netezza Platform Development Software. |
nzds show -caCertFile path | Specifies the path name of the root CA certificate file on the client system. This argument is used by clients who use peer authentication to verify the Netezza Performance Server host system. The default value is NULL, which skips the peer authentication process. |
nzds show -securityLevel level | Specifies the security level that you want to use for the session.
This option does not apply when you are logged in to the Netezza Performance Server system
and running the command. The argument has four values:
|
nzds show -regenStatus [-detail] | Displays information about the status of any disk regenerations that are in progress. The
command displays information about the Data Slice being regenerated, its SPU owner, the Source data
slice ID, its Destination data slice ID, the Start Time of the regeneration, and % Done. Include the -detail option for more information such as the locations of the SPUs and storage areas. The |
nzds show -issues [-detail] | Displays information about data slices that are reporting problems.
The command displays a list of data slices to investigate and their
Status, SPU, Primary Storage, Mirror Storage, and % Used. Include the -detail option for more information such as location details and data slice size. Note: The size of the
data slice is reported in gibibytes, which is in units of 10243 bytes.
|
nzds rebalance |
nzds has a new subcommand rebalance. Each data slice is "owned" by an SPU node that services query snippets against that data slice. The content of a data slice (subsets of rows from user tables in the system) is stored on a primary copy and a mirror copy. Under normal circumstances, the primary copy of a data slice is stored on a disk that is locally attached to the SPU that owns the data slice, which is ideal for query performance. After one or more disk or SPU failovers and or activations, it is possible for some data slices to become "remote", in that the primary copy of a data slice is on a disk that is not local to the SPU that owns the data slice. In addition, the distribution of primary data slices copies across disks and SPUs can become unbalanced. Both of the above degrade query performance, which can be improved by running the nzds
rebalance command. This command makes the SPU that holds (on one of its disks) the primary
copy of a data slice the owner of that data slice. Additionally, nzds rebalance
regenerates some primary data slice copies on different SPUs to achieve better balancing. If any
rebalancing of either kind is needed, this command causes a system state change (from
After multiple hardware failovers, |
Options
Option | Description |
---|---|
-host hostname | Specifies the host name or IP address of the Netezza Performance Server system. |
-u user | Specifies the database user name [NZ_USER]. |
-pw password | Specifies the user password [NZ_PASSWORD]. |
-timeout secs | Specifies the amount of time in seconds to wait for the command to complete before it exits with a timeout error. Default is 300. |
Description
- Privileges required
- Your database user account does not require any special administrative privileges to run the nzds show command.
- Common tasks
- Use the nzds command to manage and display information about the data slices in the system. You can also use this command to create a balanced topology for best performance of the system.
Usage
- To show information about regenerations that are in progress:
nzds show -regenstatus Data Slice SPU Source Destination Start Time % Done ---------- ---- ------ ----------- ----------------------- -------- 5 1092 1035 1014 09-Apr-09, 07:24:55 EDT 0.01 6 1092 1035 1014 09-Apr-09, 07:24:55 EDT 0.01
- To show the data slice information for the system, use the following
command:
nzds show Data Slice Status SPU Partition Size (GiB) % Used Supporting Disks ---------- ------- ---- --------- ---------- ------ --------------- 1 Healthy 1017 2 356 58.54 1021,1029 2 Healthy 1017 3 356 58.54 1021,1029 ...
The sample output that is shown for this command is truncated for the documentation.
- To show the data slice issues reported for the system, use the
following command:
nzds show -issues Data Slice Status SPU Partition Size (GiB) % Used Supporting Disks ---------- -------- ---- --------- ---------- ------ ---------------- 11 Degraded 1113 4 356 11.80 1091 12 Degraded 1113 5 356 11.79 1091
- To change the system state, run the following
command:
nzds rebalance This operation causes system state change. Are you sure you want to proceed (y|n)? [n]