>=20 > Since you're using Ubuntu 12.04, I strongly suggest upgrading your core > to 12.04.4 and apply the linux-generic-lts-saucy pseudo-package to at > least get onto the 3.11 instead. The 3.2 kernel is pants-on-head > retarded; we've had a lot more luck with 3.8 and above. >=20 Without trying to hijack this thread, is there any documentation around recommended or known-good kernels for Postgres/DB type workloads? I can see there has been a lot of discussion around recent kernel developments being detrimental (or potentially detrimental) - http://www.postgresql.org/message-id/20140115141408.GJ4963@suse.de - , but there doesn=E2=80=99t seem to be a definitive resource to know which kernels to avoid. I ask because I=E2=80=99ve just read your statement above about 3.2 being pants-on-head, and having had more luck with 3.8 and above =E2=80=93 despite most installations being on much older (2.6.19) kernels (as per the thread). I=E2=80=99d be interested to see how much benefit we=E2=80=99d get from moving off 3.2,= but I=E2=80=99d like to be aware of the risks of more recent kernel version=E2=80=99s also. Cheers, TIm --B_3485492367_119388238 Content-type: text/html; charset="UTF-8" Content-transfer-encoding: quoted-printable

From: Shaun Thomas <sthomas@optionshouse.com>
Date: Tuesday, 10 June 2014 22:07
So here's the= thing. The Linux page reclamation code is *extremely
broken* in = everything before 3.11. Take a look at this, then realize
that th= is is *only one patch* from several that target the memory
manage= r weightings:

<snipped>

Since you= 're using Ubuntu 12.04, I strongly suggest upgrading your core

to= 12.04.4 and apply the linux-generic-lts-saucy pseudo-package to at

least get onto the 3.11 instead. The 3.2 kernel is pants-on-head

retarded; we've had a lot more luck with 3.8 and above.

<= /div>

Without trying to hijack this thre= ad, is there any documentation around recommended or known-good kernels for = Postgres/DB type workloads?

I can = see there has been a lot of discussion around recent kernel developments bei= ng detrimental (or potentially detrimental) - http://www.postgresql.o= rg/message-id/20140115141408.GJ4963@suse.de - , but there does= n’t seem to be a definitive resource to know which kernels to avoid.

I ask because I’ve just read your state= ment above about 3.2 being pants-on-head, and having had more luck with 3.8 = and above – despite most installations being on much older (2.6.19) ke= rnels (as per the thread).

I’d be interested to see how much= benefit we’d get from moving off 3.2, but I’d like to be aware = of the risks of more recent kernel version’s also.

Cheers,

TIm

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