Re: Restart after poweroutage

Tom Lane wrote:
> Jon Lapham <lapham(at)jandr(dot)org> 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(at)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(at)jandr(dot)org> Rio de Janeiro, Brasil
Personal: http://www.jandr.org/
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