sis

NAME

na_sis - Advanced Single Instance Storage (SIS) management.

SYNOPSIS

sis on path

sis off path

sis start -s [ -f ] path

sis stop path

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

DESCRIPTION

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

The Advanced SIS is only available on NearStore platforms. An advanced_sis license on the 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:

on

Enables SIS on a volume. The specified volume must be an online flexible volume in order to be enabled.

In this release the SIS operation only works on SnapVault secondary volumes. It will be kicked off at the end of SnapVault transfers.

Users can also manually start an SIS operation for all the existing data blocks with the start -s subcommand.

off

Disables SIS on a volume. If an SIS operation is active on the volume, it needs to be stopped by "sis stop" before disabling.

start

Start an 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.

In this release, the -s option must be 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 -f option to suppress the confirmation.

stop

Abort the currently active SIS operation on the volume. SIS will remain enabled and the operation can be started again by the completion of next SnapVault transfer.

status

Report the status of SIS volumes. If one or more path are specified, the command will only display the status of the specified volumes. The -l option will display detailed status.

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

EXAMPLES

The following example shows the status output in short format: 

         toaster> sis status
         Path                State       Status    Progress
         /vol/dvol_1         Enabled     Idle      Idle for 10:45:23
         /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

The dvol_1 is Idle. The last SIS operation on the volume was finished 10:45:23 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 following examples shows the sis status output in long format: 

         toaster> sis status -l /vol/dvol_6
         Path:                   /vol/dvol_6
         State:                  Enabled
         Status:                 Active
         Progress:               41020 KB (20%) Done
         Type:                   Regular
         Schedule:               sun-sat@0
         Last Operation Begin:   Thu Mar 24 13:30:00 PST 2005
         Last Operation End:     Fri Mar 25 00:34:16 PST 2005
         Last Operation Size:    4732932 KB
         Last Operation Error:   -

         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 18:33:00 PST 2005
         Last Operation End:     Fri Mar 23 20:24:36 PST 2005
         Last Operation Size:    5641028 KB
         Last Operation Error:   -

SEE ALSO

na_license(1)