Postgres 卡在恢復模式

我有一個處於恢復模式的獨立 PostgreSQL 實例。一直在說

2014-03-24 18:45:57 MDT FATAL:  the database system is starting up

幾個小時，並ps顯示：

postgres  2637  0.1  0.1 116916  4420 ?        Ds   15:43   0:18 postgres: startup process   recovering 00000001000000040000007E

有什麼方法可以觀察恢復的進度，最好是使用 ETA？我怎樣才能讓這個過程“不卡住”？

我可以使用標準的啟動/停止腳本停止 postgres，但是當我再次啟動它時，它仍然停留在恢復模式。

Debian 7.4、Linux 核心 3.2.0、PostgreSQL 9.1.12

---

輸出strace -p 2637：

Process 2637 attached - interrupt to quit
close(154)                              = 0
getppid()                               = 2600
open("pg_clog/0003", O_RDWR|O_CREAT, 0600) = 154
lseek(154, 221184, SEEK_SET)            = 221184
write(154, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 8192) = 8192
fsync(154)                              = 0

上述輸出看似無限重複。

---

一個 gdb 回溯（三個後續 bts 幾乎都是相同的）：

(gdb) bt
#0  0x00007f0c8f917d70 in fsync () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007f0c9169f255 in pg_fsync_no_writethrough (fd=<optimized out>) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/storage/file/fd.c:286
#2  0x00007f0c9169f265 in pg_fsync (fd=<optimized out>) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/storage/file/fd.c:274
#3  0x00007f0c9151917b in SlruPhysicalWritePage (ctl=ctl@entry=0x7f0c91b856c0, pageno=pageno@entry=123, slotno=slotno@entry=3, fdata=fdata@entry=0x0) at /home/cbe/projects/postgresql/9.1/postgresql-9.1- 9.1.12/build/../src/backend/access/transam/slru.c:801
#4  0x00007f0c91519925 in SlruInternalWritePage (ctl=ctl@entry=0x7f0c91b856c0, slotno=3, fdata=fdata@entry=0x0) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/slru.c:528
#5  0x00007f0c9151a1c7 in SimpleLruWritePage (ctl=ctl@entry=0x7f0c91b856c0, slotno=<optimized out>) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/slru.c:565
#6  0x00007f0c915018e3 in clog_redo (lsn=..., record=<optimized out>) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/clog.c:720
#7  0x00007f0c91515f08 in StartupXLOG () at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/xlog.c:6664
#8  0x00007f0c91518537 in StartupProcessMain () at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/xlog.c:10179
#9  0x00007f0c9152f1ba in AuxiliaryProcessMain (argc=<optimized out>, argc@entry=2, argv=<optimized out>, argv@entry=0x7fff651b0610) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/bootstrap/bootstrap.c:409
#10 0x00007f0c9167ddeb in StartChildProcess (type=StartupProcess) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/postmaster/postmaster.c:4512
#11 0x00007f0c916806ac in PostmasterMain (argc=argc@entry=5, argv=argv@entry=0x7f0c91d8e180) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/postmaster/postmaster.c:1118
#12 0x00007f0c914d392f in main (argc=5, argv=0x7f0c91d8e180) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/main/main.c:209

如果我設置：

fsync = off

並再次執行 bt：

(gdb) bt
#0  0x00007f3d99ab7160 in write () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007f3d9b6be0c6 in SlruPhysicalWritePage (ctl=ctl@entry=0x7f3d9bd2a6c0, pageno=pageno@entry=123, slotno=slotno@entry=3, fdata=fdata@entry=0x0) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/slru.c:783
#2  0x00007f3d9b6be925 in SlruInternalWritePage (ctl=ctl@entry=0x7f3d9bd2a6c0, slotno=3, fdata=fdata@entry=0x0) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/slru.c:528
#3  0x00007f3d9b6bf1c7 in SimpleLruWritePage (ctl=ctl@entry=0x7f3d9bd2a6c0, slotno=<optimized out>) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/slru.c:565
#4  0x00007f3d9b6a68e3 in clog_redo (lsn=..., record=<optimized out>) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/clog.c:720
#5  0x00007f3d9b6baf08 in StartupXLOG () at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/xlog.c:6664
#6  0x00007f3d9b6bd537 in StartupProcessMain () at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/access/transam/xlog.c:10179
#7  0x00007f3d9b6d41ba in AuxiliaryProcessMain (argc=<optimized out>, argc@entry=2, argv=<optimized out>, argv@entry=0x7fff99d477a0) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/bootstrap/bootstrap.c:409
#8  0x00007f3d9b822deb in StartChildProcess (type=StartupProcess) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/postmaster/postmaster.c:4512
#9  0x00007f3d9b8256ac in PostmasterMain (argc=argc@entry=5, argv=argv@entry=0x7f3d9d614180) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/postmaster/postmaster.c:1118
#10 0x00007f3d9b67892f in main (argc=5, argv=0x7f3d9d614180) at /home/cbe/projects/postgresql/9.1/postgresql-9.1-9.1.12/build/../src/backend/main/main.c:209

在Google上搜尋了幾個小時後，我偶然發現了一個與我的問題無關的執行緒，我能說的最好，但它似乎無害，可以嘗試，瞧！

我看了看/var/lib/postgresql/9.1/main/pg_clog，發現：

drwx------  2 postgres postgres   4096 Mar 15 15:20 .
drwx------ 13 postgres postgres   4096 Mar 25 12:15 ..
-rw-------  1 postgres postgres 262144 Feb  4 19:39 0000
-rw-------  1 postgres postgres 262144 Feb 13 11:10 0001
-rw-------  1 postgres postgres 262144 Mar 15 15:20 0002
-rw-------  1 postgres postgres 229376 Mar 25 14:51 0003

注意到這/var/lib/postgresql/9.1/main/pg_clog/0003是在輸出中打開/查找的文件strace，並且這是論壇文章中有問題的文件，我在論壇中嘗試了建議的操作：

dd if=/dev/zero bs=8k count=1 >> /var/lib/postgresql/9.1/main/pg_clog/0003

現在 postgres 又開始了。

引用自：https://dba.stackexchange.com/questions/61650