Before performing a recover, the user needs to determine the save set (ssid) and the destination device. The destination device must be specified even though it is an original device that was backed up.
If the user wants to know all the device sets, then attribute 'cover' can be used in mminfo. For instance, "mminfo -aVvot -q cover" would display all the cover save sets. If the user wants to recover a specific device set, then a media database query should be performed on the device set name to determine the device set's ssid. The device set is registered in media database as a cover save set (used as a container set), ssflags in mminfo should contain 'K' along with other flags which indicate the save set is a cover set. Next, a detailed media database query on this ssid should be performed using "mminfo -S -q "ssid=xxx" to determine all the connected save set ids (See mminfo (1m)). The connected save sets are backups of all the device entries of a device set.
The nsrscsi_recover program will fork a recover thread per save set id to be recovered. The recover thread is responsible for establishing a recover session with NetWorker server and restoring the data to the destination device. For instance, if the user gives ten ssids to be recovered and each ssid is targeted to restore to unique target device, then ten recover threads will be running in parallel. The total number of threads run are directly proportional to number of save set ids to be restored.
If the target-device is a SYMMETRIX device, then it must contain SYMMETRIX id and SYMMETRIX device id (See options section below for syntax of the target-device ). The nsrscsi_recover program directly interacts with the SYMMETRIX device via SYMAPI library and discovers the host accessible raw device path for the corresponding SYMMETRIX device id. It then performs SCSI recover to the raw device path. (Refer to SYMMETRIX documentation for more details on SYMMETRIX and SYMAPI.)
Examples of a target-device
raw device /dev/rdsk/c1t2d0s2 SYMMETRIX device 00343456567/0366 where SymId is 00343456567 and DevId is 0366.
Inputfile can be an absolute path to the file that needs to be read, or inputfile can be "-" which means read device entries from stdin.
Each entry in the input-filename must contain save set ids mapped to target devices in the following format:- SSID=> target-device
/nsr/res/ora-restore1.res 2343542342=>00343456567/0366 2363572344=>00343456567/0367 2373562345=>00343456567/0368 Please note separator "=>" is required between the source and the target /nsr/res/ora-restore2.res 2343542342=>/dev/rdsk/c1t0d1s2 2343642343=>/dev/rdsk/c1t1d2s2 2343742344=>/dev/rdsk/c1t2d3s2
The target-devices in the input-filename must be either raw device entries or SYMMETRIX device entries but cannot have both.
1. Each save set to be recovered (ssid) should be mapped to a unique target device. Multiple save set recovers to the same target device would overwrite the device. 2. The disk capacity of the target has to be same as the source. If target capacity is less than source, then recover will not complete. If the target capacity is more then the target will loose disk capacity as it will have to be relabeled with smaller capacity. 3. The nsrscsi_recover program checks whether target-device is a raw device or not. If target-device is a host accessible raw device, then nsrscsi_recover will ignore vendor-plugin-name. Otherwise, the nsrscsi_recover program uses vendor-plugin-name from the -V option or the media database. 4. Currently "emc_symm" is the only supported storage vendor. For other vendors the raw device path can be attempted. 5. The recover of logical device set is not yet supported but there is a workaround to get the list of ssids from cover set using mminfo query based on device set name.