NAME

sam-verifyd - Oracle HSM Periodic Media Validation (PMV) daemon

SYNOPSIS

∕opt∕SUNWsamfs∕sbin∕sam-verifyd mshmid pshmid

AVAILABILITY

SUNWsamfs

DESCRIPTION

The sam-verifyd daemon starts and monitors the execution of periodic media validation for Oracle HSM tape libraries. The sam-verifyd daemon is started automatically by the sam-amld daemon when enabled in the verifyd.cmd file and tape libraries are defined in the mcf file. For more information about PMV configuration and policy, see the verifyd.cmd (4) man page.

The PMV daemon is responsible for monitoring the Oracle HSM preview table for VSNs wanted. If a VSN is wanted by Oracle HSM then the daemon will stop a running media validation and not interfere with the VSN or tape drive. The PMV daemon runs at the lowest priority in Oracle HSM.

Media selected for validation by PMV is based on the VSN's last verified time, last modified time, and last mounted time.

A media validation is either a 6 or 16 byte SCSI Verify Command. The default media validation for the STK T10000 series tape drives is the "standard" or edge scan which takes about 20 minutes to complete. The default media validation for all other tape drives or bad media is the "legacy" scan which may take hours to complete. The STK T10000A and T10000B tape drives only support "legacy" scan.

Defects found during a media validation are collected in a VSN defects database. PMV can be configured to use the VSN defects information to set the file re-archive bit for files with tape defects and to set the VSN recycle bit based on the number permanent errors found during media validations. Oracle HSM will select which archive copy is used to replace the defective file archive on tape. The defects database directory is ∕var∕opt∕SUNWsamfs∕samv. The defects database can be accessed using the tpverify (1m) command.

Oracle HSM has an interface for the Oracle StorageTek Tape Analytics (STA) product. STA can be configured to push media validation information to PMV for defects processing. PMV will update STA after a scan by unloading the drive when the scan completes. PMV removes the sta.timestamp files as they are processed.

The format for a sta.timestamp file is as follows: timestamp,barcode,library-usn,scan-type,result,position

The sequence of events when a STA media validation file contains information about a failed scan: the sta.timestamp file is detected, read, and removed by PMV. PMV sets bad media for the VSN in the Oracle HSM media catalog, makes a defect entry in the defects database, issues a tpverify command, the tpverify command verifies to the BOT side of the defect then FSF 1 over the defect, the defect's length is updated in the defects database, tpverify continues to verify to EOT. PMV uses the defect entries when scanning one or more file systems to set the reach bit for files with bad blocks on media. The VSN recycle bit is set in the Oracle HSM media catalog if the user policy for the number of allowed permanent errors is exceeded. The Oracle HSM archiver will detect a file's rearch bit and make a new archive copy. If needed, the user will manually recycle the VSN.

The sam-verifyd arguments are as follows:

mshmid: The identifier of the master shared memory segment created by the sam-amld daemon.
pshmid: The identifier of the preview shared memory segment created by the sam-amld daemon.

FILES

verifyd.cmd: The configuration file for Oracle HSM Periodic Media Validation.
defaults.conf: Configure sam-verifyd daemon tracing.