Tom Lane wrote:
Jon Lapham <lapham@xxxxxxxxx> writes:
To stress test, I turned off the power while actively processing db
operations, such as: loading data into a database, create a new
database, delete contents of a large table within a transaction.
Anyway, in every case I could not reproduce the issue, postgresql came
back flawlessly. I am willing to run any power outage simulation tests
people may have.
It seems unlikely to me that this issue has anything to do with what
the database was doing at the time of the system crash. More likely
the critical variable is some other software on your system. What
other shared memory segments besides Postgres' exist when your system
is operating normally?
So, you want the output of "sudo ipcs -m"? Just looking at the
information, I can't imagine that this is useful to you... but, it is
attached below.
Is it important for you to know that at the time of the power outage, I
*did* have 2 closed source kernel modules loaded, vmware's and NVidia's.
(This is a development machine, not production...). Could one of
these modules screwed up somehow and trampled on postgres's shared
memory space? Anyway, just thought I'd mention it.
lapham@bilbo > sudo ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 0 root 777 94208 0
0x00000000 98305 gdm 600 393216 0
0x00000000 41517058 lapham 600 393216 2 dest
0x6a6b6cbd 53411843 lapham 600 384 0
0x12ac1925 53444612 lapham 600 131072 0
0x000a1de2 41451525 lapham 600 1 0
0x6499077f 41484294 lapham 600 1 0
0x00000000 41549831 lapham 600 393216 2 dest
0x00000000 41582600 lapham 600 393216 2 dest
0x00000000 41615369 lapham 600 393216 2 dest
0x00000000 41648138 lapham 600 393216 2 dest
0x00000000 41680907 lapham 600 393216 2 dest
0x00000000 41713676 lapham 600 393216 2 dest
0x00000000 41746445 lapham 600 393216 2 dest
0x00000000 41779214 lapham 600 393216 2 dest
0x00000000 41844751 lapham 600 393216 2 dest
0x00000000 41877520 lapham 600 393216 2 dest
0x00000000 41910289 lapham 600 393216 2 dest
0x00000000 59539474 lapham 666 28800 1 dest
0x00000000 43450387 lapham 600 393216 2 dest
0x00000000 44990484 lapham 600 393216 2 dest
0x00000000 48234517 lapham 600 12288 2 dest
0x00000000 43483158 lapham 600 393216 2 dest
0x00000000 59277335 lapham 600 393216 2 dest
0x0052e2c1 8192026 postgres 600 10461184 2
0x00000000 49086493 lapham 600 393216 2 dest
0x00000000 48267296 lapham 600 393216 2 dest
0x00000000 48300065 lapham 600 12288 2 dest
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Jon Lapham <lapham@xxxxxxxxx> Rio de Janeiro, Brasil
Personal: http://www.jandr.org/
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