linux – 如果我强制ZFS分离没有有效副本的热备份会怎么样？

我有一个由6个RAIDZ组成的ZFS池.其中一个RAIDZ降级,原因是单个RAIDZ中的两个磁盘松散合在一起足以使ZFS无法在第二个磁盘发生故障之前从第一个故障中恢复.以下是重启后不久“zpool status”的输出：

pool: pod2
 state: DEGRADED
status: One or more devices has experienced an error resulting in data
        corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
        entire pool from backup.
   see: http://www.sun.com/msg/ZFS-8000-8A
 scrub: resilver in progress for 0h6m,0.05% done,237h17m to go
config:

        NAME                                                 STATE     READ WRITE CKSUM
        pod2                                                 DEGRADED     0     0 29.3K
          raidz1-0                                           ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F165XG    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F1660X    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F1678R    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F1689F    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F16AW9    ONLINE       0     0     0
          raidz1-1                                           ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F16C6E    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F16C9F    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F16FCD    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F16JDQ    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F17M6V    ONLINE       0     0     0
          raidz1-2                                           ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F17MSZ    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F17MXE    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F17XKB    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F17XMW    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F17ZHY    ONLINE       0     0     0
          raidz1-3                                           ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F18BM4    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F18BRF    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_W1F18XLP    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F09880    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F098BE    ONLINE       0     0     0
          raidz1-4                                           DEGRADED     0     0 58.7K
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F09B0M    ONLINE       0     0     0
            spare-1                                          DEGRADED     0     0     0
              disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F09BEN  UNAVAIL      0     0     0  cannot open
              disk/by-id/scsi-SATA_ST3000DM001-1CH_W1F49M01  ONLINE       0     0     0  837K resilvered
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0D6LC    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0CWD1    ONLINE       0     0     0
            spare-4                                          DEGRADED     0     0     0
              disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F09C8G  UNAVAIL      0     0     0  cannot open
              disk/by-id/scsi-SATA_ST3000DM001-1CH_W1F4A7ZE  ONLINE       0     0     0  830K resilvered
          raidz1-5                                           ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-1CH_Z1F2KNQP    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BML0    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BPV4    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BPZP    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BQ78    ONLINE       0     0     0
          raidz1-6                                           ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BQ9G    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BQDF    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BQFQ    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0CW1A    ONLINE       0     0     0
            disk/by-id/scsi-SATA_ST3000DM001-9YN_Z1F0BV7M    ONLINE       0     0     0
        spares
          disk/by-id/scsi-SATA_ST3000DM001-1CH_W1F49M01      INUSE     currently in use
          disk/by-id/scsi-SATA_ST3000DM001-1CH_W1F4A7ZE      INUSE     currently in use
          disk/by-id/scsi-SATA_ST3000DM001-1CH_W1F49MB1      AVAIL   
          disk/by-id/scsi-SATA_ST3000DM001-1ER_Z5001SS2      AVAIL   
          disk/by-id/scsi-SATA_ST3000DM001-1ER_Z5001R0F      AVAIL   

errors: 37062187 data errors,use '-v' for a list

当第一个磁盘发生故障时,我用热备件替换它,它开始重新启动.在重新启动完成之前,第二个磁盘发生故障,因此我用另一个热备份替换了第二个磁盘.从那以后它将开始重新启动,完成大约50％,然后开始吞噬内存,直到它全部吃完并导致操作系统崩溃.

此时升级服务器上的RAM并不是一个简单的选择,我不清楚这样做是否可以保证解决方案.我知道在这个阶段会有数据丢失,但如果我可以牺牲这个RAIDZ的内容来保留池的其余部分,这是一个完全可以接受的结果.我正在将此服务器的内容备份到另一台服务器,但内存消耗问题每48小时左右强制重启(或崩溃),这会中断我的rsync备份,并重新启动rsync需要时间(它可以一旦它确定它停止的地方就恢复,但这需要很长时间).

我认为ZFS试图处理两个备用替换操作是内存消耗问题的根源,因此我想删除其中一个热备件,以便ZFS可以一次处理一个.但是,当我尝试分离其中一个备件时,我得到“无法分离/ dev / disk / by-id / scsi-SATA_ST3000DM001-1CH_W1F49M01：没有有效的副本”.也许我可以使用-f选项来强制操作,但我不清楚它的确切结果是什么,所以我想看看是否有人在继续之前有任何输入.

如果我可以让系统进入一个稳定的状态,它可以保持足够长的时间运行以备份完成,我计划将其关闭以进行大修,但是在目前情况下,它会陷入一些恢复循环.

解决方法

现在你可以分离UNAVAIL磁盘,ZFS不再使用它们了.

您在RAIDZ-1设置中有两个故障磁盘.您很可能正在查看一些数据丢失,并准备从备份中恢复.

另外,在我使用OpenSolaris / Solaris11时,RAIDZ已经证明非常不稳定.我建议不要在任何类型的生产工作量中使用它.

另外,为了强化ewwhite所说的,FUSE不是你最好的选择.我借此机会迁移到更稳定的东西(也许是FreeBSD 10).