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na_sis - Advanced Single Instance Storage (SIS) management.


sis config [ [ -s schedule ] path | path ... ]

sis on path

sis off path

sis start [-s] [ -f ] [-d] [-sp] path

sis stop path

sis status [ -l ] [ [ path ] ... ]


The sis command is used to manage SIS operations, a method of reducing disk space usage by eliminating duplicate data blocks on a flexible volume. Only a single instance of each unique data blocks will is stored.

The Advanced SIS is only available on NearStore platforms. An a_sis license on NearStore platforms is required to enable the feature. See na_license(1) for more details.

The path parameter is the full path of a flexible volume, its format is /vol/vol_name.

The sis subcommands are:


Setup, modify, and retrieve the schedule or the options of a SIS volume. Currently, the config command is only used to schedule.

The option -s is used to setup or modify the schedule on the specified path. Otherwise, the schedule of the specified path is displayed. If no option or path is specified, then the schedule of all the configured SIS volumes is displayed.

  schedule is [day_list][@hour_list]
        or [hour_list][@day_list]
        or -
        or auto

The day_list specifies which days of the week SIS operations should run. It is a list of the first three letters of the day ( sun, mon, tue, wed, thu, fri, sat ) saperated by comma. Day ranges such as mon-fri can also be used. The default day_list is sun-sat. The names are not case sensitive.

The hour_list specifies the hours of each scheduled day that a SIS operation should run. The hour_list is from 0 to 23 saperated by comma. Hour ranges such as 8-17 are allowed. Step values can be used in conjunction with ranges (For example, 0-23/2 means every two hours in a day). The default hour_list is 0, i.e. at midnight on the morning of each scheduled day.

If "-" is specified, there would not be scheduled SIS operation on the volume. When a non-SIS volume is enabled the first time, an initial schedule is assigned to the volume. This initial schedule is [email protected], which means once everyday at midnight.

The auto schedule string triggers a SIS operation depending on the amount of new data written to the volume. The criterion is subject to be changed later.


The on command enables SIS operation on a volume. The specified volume must be an online FlexVol volume in order to be enabled.

On a regular volume, SIS operations will be started periodically according to a per-volume schedule. On a SnapVault secondary volume, SIS operations will be triggered at the end of SnapVault transfers.

The schedule can be modified by the config subcommand. You can also manually start an SIS operation with the start subcommand.


The off command disables SIS operation on a volume. If a SIS operation is active on the volume, it needs to be stopped using sis stop before using the sis off command.


Use the start command to start SIS operation. The volume must be enabled and online before starting the SIS operation. If the SIS operation is already active on the volume, this command will fail.

If the -s option is specified, the SIS operation will scan the file system to process all the existing data. With the -s option, SIS operation will prompt for user confirmation before proceeding. Use the -f option to suppress the confirmation. When a sis start command is issued, a checkpoint is created at the end of each stage or sub-stage, or on hourly basis in gathering phase. If at any point the SIS start operation is stopped, system can restart from the execution state saved in the checkpoint next time the operation starts. The -d option can be used to delete the existing checkpoint and restart a fresh sis start operation. The checkpoint corresponding to gathering phase has validity of 24 hours. If the user knows that significant changes have not been made on the volume then such a gatherer checkpoint whose validity has expired can be used with help of -sp option. There is no time restriction for checkpoints of other stages. In this release, whole volume scanning is supported on all FlexVol volumes.


Use the stop command to abort the active SIS operation on the volume. SIS will remain enabled and the operation can be started again by using the start subcommand, SnapVault transfer, or the scheduler.


Use the status command to report the status of SIS volumes. If one or more paths are specified, the command will only display the status of the specified volumes. The -l option will display the detailed status.

The df -s command will show the space savings generated by SIS operations (see na_df(1)).


sis status

This command displays the status of all SIS volumes. The following example shows the status output in short format:

  toaster> sis status
  Path                State       Status    Progress
  /vol/dvol_1         Enabled     Idle      Idle for 04:53:29
  /vol/dvol_2         Enabled     Pending   Idle for 15:23:41
  /vol/dvol_3         Disabled    Idle      Idle for 37:12:34
  /vol/dvol_4         Enabled     Active    25 GB Scanned
  /vol/dvol_5         Enabled     Active    25 MB Searched
  /vol/dvol_6         Enabled     Active    40 MB (20%) Done
  /vol/dvol_7         Enabled     Active    30 MB Verified
  /vol/dvol_8         Enabled     Active    10% Merged

The dvol_1 is Idle. The last SIS operation on the volume was finished 04:53:29 ago.

The dvol_2 is Pending for resource limitation. The SIS operation on the volume will become Active when the resource is available.

The dvol_3 is Idle because the SIS operation is disabled on the volume.

The dvol_4 is Active. The SIS operation is doing the whole volume scanning. So far, it has scanned 25GB of data.

The dvol_5 is Active. The operation is searching for duplicated data, there are 25MB of data already searched.

The dvol_6 is also Active. The operation has saved 40MB of data. This is 20% of the the total duplicate data found in the searching stage.

The dvol_7 is Active. It is verifying the metadata of processed data blocks. This process will remove unused metadata.

The dvol_8 is Active. Verified metadata is being merged. This process will merge together all verified metadata of processed data blocks to an internal format which supports fast sis operation.

The following examples shows the sis status output in long format:

         toaster> sis status -l /vol/dvol_1
         Path:                    /vol/dvol_1
         State:                   Enabled
         Status:                  Idle
         Progress:                Idle for 04:53:29
         Type:                    Regular
         Schedule:                -
         Last Operation Begin:    Fri Jul 26 05:32:44 GMT 2007
         Last Operation End:      Fri Jul 26 06:15:51 GMT 2007
         Last Operation Size:     3200 MB
         Last Operation Error:    -
         Changelog Usage:         0%
         Checkpoint Time:         Fri Jul 27 06:00:00 GMT 2007
         Checkpoint Op Type:      Start
         Checkpoint Stage:        Dedup_P1
         Checkpoint Sub-Stage:    Pass2
         Checkpoint Progress:     -

         toaster> sis status -l /vol/dvol_8
         Path:                   /vol/dvol_8
         State:                  Enabled
         Status:                 Active
         Progress:               51208 KB Searched
         Type:                   SnapVault
         Schedule:               -
         Last Operation Begin:   Thu Mar 23 19:54:00 PST 2005
         Last Operation End:     Fri Mar 23 20:24:36 PST 2005
         Last Operation Size:    5641028 KB
         Last Operation Error:   -
         Changelog Usage:        1%
         Checkpoint Time:         Fri Mar 23 20:00:00 PST 2005
         Checkpoint Op Type:      Scan
         Checkpoint Stage:        Gathering
         Checkpoint Sub-Stage:    -
         Checkpoint Progress:     0.4 MB (20%) Gathered

sis config

This command displays the schedule for all SIS enabled volumes. The following example shows the config output:

  toaster> sis config
  Path                            Schedule
  /vol/dvol_1                         -
  /vol/dvol_2                     [email protected]
  /vol/dvol_3                     auto

Sis on the volume dvol_1 is not scheduled.

Sis on the volume dvol_2 is scheduled to run everyday from Sunday to Friday at 11 PM.

Sis on the volume dvol_3 is set to auto schedule.


na_df(1) na_license(1)

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