NAME

tkadmin restore lvols - restores the contents of one or more logical volumes

SYNOPSIS

tkadmin restore lvols -server servername nvols {(lvolname [-backupfilenum backupfilenum])...} [-noresume]

ARGUMENTS

-server servername Specifies the server affected by the command. The server name is the name that is registered with the DCE Directory Service. If the server name is not specified in the command line, it is retrieved from an environment variable, ENCINA_TK_SERVER. 

nvols Specifies the number of volumes to restore. 

lvolname Specifies the logical volume to restore. 

[-backupfilenum backupfilenum]
Specifies the sequence number of the most recent backup file to restore from. Default is the number of the last complete backup of the volume.

[-noresume] Alerts the server to restart the restore process (not to resume the interrupted restore of volumes, the default behavior). 

DESCRIPTION

The tkadmin restore lvols command restores a set of volumes from a backup. Restoring several volumes at a time is more efficient than restoring each of them separately. For each volume to restore, you specify the backup to use (via the sequence number of the most recent file in the backup) and the volume name. 

Since each server has a single log file, restoring multiple volumes via separate invocations of the restore command requires reading the same log file several times. To avoid this, the restore command accepts a list of volumes to be restored concurrently. However, you can have only a single outstanding restore request at any given time. You should not issue a second tkadmin restore lvols command until the first is complete. If a second restore process (of the same or another volume) is invoked via this command, the first is terminated. Restore processes terminated in this manner cannot be resumed. 

If the command fails to complete (either due to a server or system failure or due to unavailable backup files), the volumes being restored are left in an indeterminate state. The command can be reissued after the server has restarted. By default, reissuing this command after a server restart resumes the restore process from where it left off. To start the restore process from the beginning (prevent it from resuming), use the -noresume option. 

When multiple volumes are restored in one command, first all backup files (from oldest to newest) are restored for each volume specified on the command line (in the order the volumes are specified). Then the server’s log file including media archive files is replayed once (from oldest archive files to newest data in log file) to update all volumes being restored. The backup files and archive files required to restore a data volume can be displayed with the tkadmin query backup command. 

CAUTIONS

The logical volumes must be disabled. (You must start the server in administrative mode.) 

The logical volume should be unmirrored. You should remove all mirrors of the volume before the restore, restore only one copy, and mirror the volume again after the restore is complete. 

EXAMPLES

The following command restores the logical volumes debitvol and creditvol from backups. Assume that the 200-kilobyte volume debitvol has 6 backup files named debitvol.TRB.000000 through debitvol.TRB.000005, 41 kilobytes each.  (200 kilobytes / 6 = 40 kilobytes; the additional 1KB is necessary to hold the backup file header information.) There are two valid backups of debitvol that can be used for a restore, backup number 4 (consisting of files 0 through 4) and backup number 5 (consisting of files 1 through 5). Similarly, the creditvol volume has two valid backups, backup number 2 (consisting of files 0 through 2), and backup number 3 (consisting of files 1 through 3). 

The following command restores debitvol using the backup number 5 and creditvol using backup number 3. Note that no backup file number is specified for the restoration of the creditvol volume as the latest complete backup (3) is used by default. 

% tkadmin restore lvols 2 debitvol -backupfilenum 5 creditvol

In cases where the backup files needed by this command are inaccessible (possibly not online), the following message is displayed:

Restore process paused due to missing backup files.
Please ensure the following backup files are available and try again.
debitvol.TRB.000001
creditvol.TRB.000001

You must make the backup files accessible and reissue the tkadmin restore lvols command. At completion, the following message is displayed:

The restore completed successfully.
Restart the server normally to begin using the restored data.

PRIVILEGE REQUIRED

Encina Monitor administer (a) permission to the node manager

Encina RQS administer (a) permission to the RQS server

Encina SFS administer (A) permission to the SFS server

RELATED INFORMATION

tkadmin backup lvol

tkadmin query backup

tkadmin query restore

  —  March 1997