Excerpts from Jon Nelson's message of 2010-12-07 13:45:14 -0500: > On Tue, Dec 7, 2010 at 12:22 PM, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > > On Tue, Dec 07 2010 at Â1:10pm -0500, > > Jon Nelson <jnelson@xxxxxxxxxxx> wrote: > > > >> I finally found some time to test this out. With 2.6.37-rc4 (openSUSE > >> KOTD kernel) I easily encounter the issue. > >> > >> Using a virtual machine, I created a stock, minimal openSUSE 11.3 x86_64 > >> install, installed all updates, installed postgresql and the 'KOTD' > >> (Kernel of the Day) > >> kernel, and ran the following tests (as postgres user because I'm > >> lazy). > >> > >> 1. create a database (from bash): > >> > >> createdb test > >> > >> 2. place the following contents in a file (I used 't.sql'): > >> > >> begin; > >> create temporary table foo as select x as a, ARRAY[x] as b FROM > >> generate_series(1, 10000000 ) AS x; > >> create index foo_a_idx on foo (a); > >> create index foo_b_idx on foo USING GIN (b); > >> rollback; > >> > >> 3. execute that sql: > >> > >> psql -f t.sql --echo-all test > >> > >> > >> With 2.6.34.7 I can re-run [3] all day long, as many times as I want, > >> without issue. > >> > >> With 2.6.37-rc4-13 (the currently-installed KOTD kernel) if tails > >> pretty frequently. > > > > How does it fail? Âpostgres errors? Âkernel errors? > > postgresql errors. Typically, header corruption but from the limited > visibility I've had into this via strace, what I see is zeroed pages > where there shouldn't be. This sounds a lot like a bug higher up than dm-crypt. Zeros tend to come from some piece of code explicitly filling a page with zeros, and that often happens in the corner cases for O_DIRECT and a few other places in the filesystem. Have you tried triggering this with a regular block device? -chris -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
