Oracle daily maintenance-free archivelog disk space

ORA_Archive_Disk_Check
1.About check_mk metric:ORA_Archive_Disk_Check
This is a custom monitoring metric on check_mk platform,
the threshold is defined in /usr/lib/check_mk_oracle/MAIN/conf1/perf_ORCL_arc_disk.json

[oracle@pcnoradb5 conf1]$ cat perf_ORCL_arc_disk.json 
{"target_info":[{
"perf_min":"0",
"chk_interval":5000,
"output_cmd":"echo",
"post_action":"",
"perf_crit":"90",
"chk_cmd":"sh run_arc_disk.sh Bakparameters_ORCL",
"perf_max":"0",
"chk_result_separator":";",
"perf_warn":"85",
"database":"ORCL"
}]}

notice the two threshold value:“perf_warn”:“85”,“perf_crit”:“90”, mean that the disk usage ratio that archive log located reach 85% will trigger warning alarm and 95%trigger critical alarm

2.Solution
2.1 get archive log location

[oracle@pcnoradb5 MAIN]$ sqlplus /nolog

SQL*Plus: Release 10.2.0.5.0 - Production on �P���� 3�� 17 14:23:47 2023

Copyright (c) 1982, 2010, Oracle.  All Rights Reserved.

SQL> connect / as sysdba
Connected.
SQL> show parameter log_archive_dest_1

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_dest_1                   string      location=/u2/archive/orcl

2.2 archive log located in /u2, right now we check disk usage by linux df command

[oracle@pcnoradb5 orcl]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              45G   39G  4.2G  91% /
/dev/sda1             2.0G   52M  1.8G   3% /boot
tmpfs                  12G     0   12G   0% /dev/shm
/dev/sdb              296G  261G   20G  93% /u1
/dev/sdc1              74G   62G  8.8G  88% /u2
172.19.5.100:/database/Oracle/005127
                      6.5T  5.6T  894G  87% /DBBACKUP

here will observed that the space usage ration was up to 88% on /u2, the warning alarm will be triggered by check_mk platform at this time

2.3 more further, we need to investigate who occupied most disk space on /u2

[oracle@pcnoradb5 orcl]$ du -sh /u2/*
62.1G     /u2/archive
16K     /u2/lost+found

The output clearly tell us that the archived logs consumed most of the disk space

next, how to do? it is not recommend to delete these archive logs directly, because these archive log will involve database disaster recovery in the future, it’s possible that will be unable to recovery database to specific time if miss these archive logs
2.4 fortunately, have a script file named rman_backup_archive.sh , which is provided by HQ DBA, in general, it is located /backup/script,
1.backup archivelog to NAS device,the NAS device was mounted in /DBBACKUP,as as you saw in previous output in step 2.2, you can manually mount it if there is not the folder in server
2.after delete archivelog under /u2/archive folder

/backup/script/rman_backup_archive.sh /backup/script/Backup_ORCL

notice, Backup_ORCL is a parameter file, localeted the same location with script file.

2.5 use df command to check again, you will be found that the disk space on /u2 already be released

[oracle@pcnoradb5 ~]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              45G   39G  4.2G  91% /
/dev/sda1             2.0G   52M  1.8G   3% /boot
tmpfs                  12G     0   12G   0% /dev/shm
/dev/sdb              296G  261G   20G  93% /u1
/dev/sdc1              74G   28G   43G  40% /u2
172.19.5.100:/database/Oracle/005127
                      6.5T  5.6T  898G  87% /DBBACKUP

if on the server did not exist the script file , you can copy from other server, or manually execute the following command in rman command line:

RUN {
ALLOCATE CHANNEL ch00 TYPE DISK;
BACKUP
   AS COMPRESSED BACKUPSET
   filesperset 20
   FORMAT '/DBBACKUP/RMAN/ARCHIVE/al_%s_%p_%T'
   ARCHIVELOG ALL DELETE INPUT;
RELEASE CHANNEL ch00; 
}