Re: Cannot mount ceph filesystem: error 5 (Input/Output error)

[Guido Winkelmann <guido-ceph@thisisnotatest.de>]

On Friday 02 December 2011 11:29:41 Samuel Just wrote:
> Guido,
> 
> Sorry for the confusion, you hit a bug where the default map for a
> cluster with one osd contains no pgs.  0.39 (which will be released
> today) will have a fix.

Really? Then why does the output of ceph -s below mention 6 pgs?

BTW, that's another aspect where the documentation is a bit lacking right now. 
I've found a page telling me how to change the number of pgs, but I couldn't 
find any explanation so far what a pg actually is, or why I should want to 
change their number...

	Guido
 
> -Sam
> 
> On Fri, Dec 2, 2011 at 8:24 AM, Guido Winkelmann
> 
> <guido-ceph@thisisnotatest.de> wrote:
> > Hi,
> > 
> > Am Freitag, 25. November 2011, 19:54:42 schrieb Wido den Hollander:
> >> Hi Guido,
> >> 
> >> On 11/25/2011 05:53 PM, Guido Winkelmann wrote:
> >> > Hi,
> >> > 
> >> > When trying to mount a Ceph filesystem with "mount.ceph
> >> > 10.3.1.33:6789:/ /mnt", the command hangs for several minutes and
> >> > then fails with the message
> >> > 
> >> > mount error 5 = Input/output error
> >> 
> >> Does "ceph -s" work? If so, what is the output?
> > 
> > It works. This is the output:
> > 
> > # ceph -s
> > 2011-11-28 18:51:32.018383    pg v60: 6 pgs: 6 active+clean+degraded; 0
> > KB data, 1292 KB used, 1750 GB / 1752 GB avail
> > 2011-11-28 18:51:32.018610   mds e11: 1/1/1 up {0=alpha=up:creating}
> > 2011-11-28 18:51:32.018698   osd e22: 1 osds: 1 up, 1 in
> > 2011-11-28 18:51:32.018767   log 2011-11-28 18:50:16.299822 mon.0
> > 10.3.1.33:6789/0 3 : [INF] mds.? 10.3.1.33:6800/21218 up:boot
> > 2011-11-28 18:51:32.018833   mon e1: 1 mons at {ceph1=10.3.1.33:6789/0}