用rman备份数据集失败，报空间不足

zhouyh139

刘大，您好：
  向您请教个问题，我的备份脚本非常简单，晚上执行的时候一直报错，空间不足，但是我白天sh执行脚本的时候又不报错误，
晚上执行的时候会产生很多日志，日志内容都是报空间不足，失败。
下面是任务列表：
* 1 * * * sh  /oradata/backup/rman_script/fullbackup.sh
下面是磁盘空间容量：
[oracle@node1 rman_log]$ df -h
文件系统              容量  已用 可用 已用% 挂载点
/dev/sda2              95G   12G   79G  13% /
/dev/sda1             289M   27M  248M  10% /boot
tmpfs                  16G  8.9G  7.2G  56% /dev/shm
/dev/sda5             826G  226G  559G  29% /oradata
/dev/sda6             697G  153G  509G  24% /oradata/backup

下面是报错内容：
RMAN-03009: failure of backup command on c1 channel at 07/02/2014 02:47:36
ORA-19502: write error on file "/oradata/backup/rman_db/full_GSTGATE_20140702_5377_1996030521.bak", block number 198528 (block size=8192)
ORA-27072: File I/O error
Linux-x86_64 Error: 28: No space left on device
Additional information: 4
Additional information: 198528
Additional information: -1
channel c1 disabled, job failed on it will be run on another channel
RMAN-03009: failure of backup command on c2 channel at 07/02/2014 02:48:11
ORA-19502: write error on file "/oradata/backup/rman_db/full_GSTGATE_20140702_5381_1996030521.bak", block number 193408 (block size=8192)
ORA-27072: File I/O error
Additional information: 4
Additional information: 193408
Additional information: 126976
channel c2 disabled, job failed on it will be run on another channel
released channel: c1
released channel: c2
released channel: c3
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on c3 channel at 07/02/2014 02:48:19
ORA-19502: write error on file "/oradata/backup/rman_db/full_GSTGATE_20140702_5385_1996030521.bak", block number 139776 (block size=8192)
ORA-27072: File I/O error
Additional information: 4
Additional information: 139776
Additional information: 266240

实际上空间应该是够的，附件是详细的脚本及日志，我白天单独执行是ok的