[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Ceph support for Direct I/O

From: Chang
Subject: Ceph support for Direct I/O
Date: Thu, 17 May 2012 21:13:07 +0000 (UTC)
User-agent: Loom/3.14 (http://gmane.org/)


I was trying to test write performance of Ceph, using direct I/O.

$ dd if=/dev/zero of=/mnt/ceph/my.dat bs=1M count=1 oflag=direct

But dd is just stuck without doing any write.

Without oflag, write is done fine.

In the above example, I used Ceph kernel module 0.20, built on kernel 2.6.32.

I also tried Ceph fuse client to mount.
In this case, the above dd command gives me:

"dd: opening `/mnt/ceph/my.dat': Invalid argument"

Is it because Ceph does not support direct I/O?

I'm using ceph 0.46, installed using Debian release package.
There are three OSDs, 1 Mon and 1 MDS in the cluster.

Any help or clarification is appreciated.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]