[Pkg-postgresql-public] Bug#684205: Bug#684205: postgresql-common: pg_checksystem sending ioctl to a partition

[Christoph Berg]

Re: Nelson A. de Oliveira 2012-08-07 <20120807193520.30305.74831.reportbug at naoliv.foa.unesp.br>
> I am unsure on how harmless it's but I am seeing this on kern.log:
> 
> [4927088.495625] pg_checksystem: sending ioctl 5401 to a partition!

At least it is intended:

sub get_device_write_cache {
    open DRV, $_[0] or return -1;
    sub HDIO_GET_WCACHE () {0x30e;}
    my $pval = pack 'l', 0;
    ioctl DRV, &HDIO_GET_WCACHE, $pval or return -1;

The check seems to be broken here. At least when using LVM, ioctl() on
the partition doesn't look through the LVM layer to check the write
cache on the base disk. (Verified by using hdparm -W 1 /dev/sda.)

Looks like we need to do something smarter for LVM systems, or at
least disable the check there.

For the actual question: yes, harmless.

Christoph
-- 
cb at df7cb.de | http://www.df7cb.de/
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