## Managing tape drive dump files 

This section describes how to manage the automatic erasure of drive dump files. IBM Spectrum Archive automatically generates two tape drive dump files in the /tmp  directory when it receives unexpected sense data from a tape drive. Example 10-1 shows the format of the dump files. 

[root@ltfs97 tmp]# ls -la *.dmp -rw-r--r-- 1 root root 3681832 Apr 4 14:26 ltfs_1068000073_2013_0404_142634.dmp -rw-r--r-- 1 root root 3681832 Apr 4 14:26 ltfs_1068000073_2013_0404_142634_f.dmp -rw-r--r-- 1 root root 3681832 Apr 4 14:42 ltfs_1068000073_2013_0404_144212.dmp -rw-r--r-- 1 root root 3697944 Apr 4 14:42 ltfs_1068000073_2013_0404_144212_f.dmp -rw-r--r-- 1 root root 3697944 Apr 4 15:45 ltfs_1068000073_2013_0404_154524.dmp -rw-r--r-- 1 root root 3683424 Apr 4 15:45 ltfs_1068000073_2013_0404_154524_f.dmp -rw-r--r-- 1 root root 3683424 Apr 4 17:21 ltfs_1068000073_2013_0404_172124.dmp -rw-r--r-- 1 root root 3721684 Apr 4 17:21 ltfs_1068000073_2013_0404_172124_f.dmp -rw-r--r-- 1 root root 3721684 Apr 4 17:21 ltfs_1068000073_2013_0404_172140.dmp -rw-r--r-- 1 root root 3792168 Apr 4 17:21 ltfs_1068000073_2013_0404_172140_f.dmp 

The size of each drive dump file is approximately 2 MB. By managing the drive dump files that are generated, you can save disk space and enhance IBM Spectrum Archive performance. 

It is not necessary to keep dump files after they are used for problem analysis. Likewise, the files are not necessary if the problems are minor and can be ignored. A script program that is provided with IBM Spectrum Archive EE periodically checks the number of drive dump files and their date and time. If some of the dump files are older than two weeks or if the number of dump files exceeds 1000 files, the script program erases them. 

The script file is started by using Linux crontab  features. A cron_ltfs_limit_dumps.sh  file is in the /etc/cron.daily  directory. This script file is started daily by the Linux operating system. The interval to run the script can be changed by moving the cron_ltfs_limit_dumps.sh  file to other cron  folders, such as cron.weekly . For more information about how to change the crontab setting, see the manual for your version of Linux. 

In the cron_ltfs_limit_dumps.sh  file, the automatic drive dump erase policy is specified by the option of the ltfs_limit_dump.sh script  file, as shown in the following example: 

/opt/IBM/ltfs/bin/ltfs_limit_dumps.sh -t 14 -n 1000 

You can modify the policy by editing the options in the cron_ltfs_limit_dumps.sh file. The expiration date is set as a number of days by the -t  option. In the example, a drive dump file is erased when it is more than 14 days old. The number of files to keep is set by the -n  option. In our example, if the number of files exceeds 1,000, older files are erased so that the 1,000-file maximum is not exceeded. If either of the options are deleted, the dump files are deleted by the remaining policy. 

By editing these options in the cron_ltfs_limit_dumps.sh  file, the number of days that files are kept and the number of files that are stored can be modified. 

Although not recommended, you can disable the automatic erasure of drive dump files by removing the cron_ltfs_limit_dumps.sh  file from the cron  folder. 

