磁盘空间不足

下面是从ERRORLOG提取的信息，部分内容有删减

2016-11-11 03:55:42.110    spid306    The transaction log for database '***StatDB' is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc column in sys.databases
2016-11-11 03:55:42.110    spid306    错误: 9002，严重性: 17，状态: 2。
2016-11-11 03:55:40.010    spid422    The transaction log for database '***StatDB' is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc column in sys.databases
2016-11-11 03:55:40.010    spid422    错误: 9002，严重性: 17，状态: 2。
2016-11-11 03:55:39.980    spid422    G:\***StatDB\***StatDB_log.ldf: Operating system error 112(磁盘空间不足。) encountered.
2016-11-11 03:55:39.980    spid422    错误: 17053，严重性: 16，状态: 1。
2016-11-11 03:50:00.250    备份    BACKUP failed to complete the command BACKUP LOG ***StatDB. Check the backup application log for detailed messages.
2016-11-11 03:50:00.250    备份    错误: 3041，严重性: 16，状态: 1。
2016-11-11 03:50:00.250    spid129    BackupMedium::ReportIoError: write failure on backup device 'G:\BackUpDB\***StatDB\***StatDB20161111350LOG.BAK'. Operating system error 112(磁盘空间不足。).
2016-11-11 03:50:00.250    spid129    错误: 18210，严重性: 16，状态: 1。
2016-11-11 03:40:00.160    备份    BACKUP failed to complete the command BACKUP LOG ***StatDB. Check the backup application log for detailed messages.
2016-11-11 03:40:00.160    备份    错误: 3041，严重性: 16，状态: 1。
2016-11-11 03:40:00.160    spid427    BackupMedium::ReportIoError: write failure on backup device 'G:\BackUpDB\***StatDB\***StatDB20161111340LOG.BAK'. Operating system error 112(磁盘空间不足。).
2016-11-11 03:40:00.160    spid427    错误: 18210，严重性: 16，状态: 1。
2016-11-11 03:30:01.090    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761874:421:1, last LSN: 761893:68:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111330LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 03:20:00.740    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761866:81:1, last LSN: 761874:421:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111320LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 03:10:01.200    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761858:15209:1, last LSN: 761866:81:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111310LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 02:50:00.170    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761858:8545:1, last LSN: 761858:15209:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111250LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 02:40:00.150    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761857:20500:1, last LSN: 761858:8545:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111240LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 02:30:00.270    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761856:13643:1, last LSN: 761857:20500:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111230LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 02:20:00.190    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761855:24711:1, last LSN: 761856:13643:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111220LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 02:10:00.180    备份    Log was backed up. Database: ***StatDB, creation date(time): 2014/10/20(18:23:55), first LSN: 761855:5494:1, last LSN: 761855:24711:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'G:\BackUpDB\***StatDB\***StatDB20161111210LOG.BAK'}). This is an informational message only. No user action is required.
2016-11-11 02:00:10.120    备份    BACKUP failed to complete the command BACKUP DATABASE ***StatDB WITH DIFFERENTIAL. Check the backup application log for detailed messages.
2016-11-11 02:00:10.120    备份    错误: 3041，严重性: 16，状态: 1。
2016-11-11 02:00:10.110    spid425    BackupMedium::ReportIoError: write failure on backup device 'G:\BackUpDB\***StatDB\***StatDB2016111120DIFF.BAK'. Operating system error 112(磁盘空间不足。).
2016-11-11 02:00:10.110    spid425    错误: 18210，严重性: 16，状态: 1。

先来看下ERRORLOG中记录了些什么
2016-11-11 02:00 差异备份失败，原因是磁盘空间不足
2016-11-11 02:10~2016-11-11 03:30 日志备份/10分钟，成功
2016-11-11 03:40~2016-11-11 03:50 日志备份/10分钟，失败，原因是磁盘空间不足
2016-11-11 03:55 Logfile encounter Operating system error 112~transaction log is full
数据库：完整恢复模式，日志文件增量为50MB，不限制最大文件大小
备份策略：完整备份/1天+差异备份/2小时+事务日志备份/10分钟
数据库文件保存在G盘，数据库备份文件同样保存在G盘
...G盘可用空间不足，差异备份失败，后续几个日志备份逐渐占用剩余空间，直到剩余空间放不下单次日志备份文件。日志不能被截断，事务持续进行，日志文件自动增长，但剩余空间不足50MB，增长失败。事务日志已满，所有涉及日志写入的操作失败。
存在问题
1、数据文件、日志文件、备份文件存放混乱
2、ERRORLOG中错误日志、磁盘可用空间没能及时预警