Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-17 Thread Jason Dillaman
On Sat, Jul 15, 2017 at 8:00 PM, Ruben Rodriguez wrote: > > > On 14/07/17 18:43, Ruben Rodriguez wrote: >> How to reproduce... > > I'll provide more concise details on how to test this behavior: > > Ceph config: > > [client] > rbd readahead max bytes = 0 # we don't want forced

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-17 Thread Jason Dillaman
On Sat, Jul 15, 2017 at 5:35 PM, Ruben Rodriguez wrote: > > > On 15/07/17 15:33, Jason Dillaman wrote: >> On Sat, Jul 15, 2017 at 9:43 AM, Nick Fisk wrote: >>> Unless you tell the rbd client to not disable readahead after reading the >>> 1st x number of bytes

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-15 Thread Ruben Rodriguez
On 14/07/17 18:43, Ruben Rodriguez wrote: > How to reproduce... I'll provide more concise details on how to test this behavior: Ceph config: [client] rbd readahead max bytes = 0 # we don't want forced readahead to fool us rbd cache = true Start a qemu vm, with a rbd image attached with

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-15 Thread Ruben Rodriguez
h-users@lists.ceph.com> >> Subject: Re: [ceph-users] RBD cache being filled up in small increases >> instead >> of 4MB >> >> On Fri, Jul 14, 2017 at 3:43 PM, Ruben Rodriguez <ru...@fsf.org> wrote: >>> >>> I'm having an issue with small sequenti

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-15 Thread Ruben Rodriguez
On 15/07/17 15:33, Jason Dillaman wrote: > On Sat, Jul 15, 2017 at 9:43 AM, Nick Fisk wrote: >> Unless you tell the rbd client to not disable readahead after reading the >> 1st x number of bytes (rbd readahead disable after bytes=0), it will stop >> reading ahead and will

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-15 Thread Jason Dillaman
On Sat, Jul 15, 2017 at 9:43 AM, Nick Fisk wrote: > Unless you tell the rbd client to not disable readahead after reading the 1st > x number of bytes (rbd readahead disable after bytes=0), it will stop reading > ahead and will only cache exactly what is requested by the client.

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-15 Thread Nick Fisk
> -Original Message- > From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of > Gregory Farnum > Sent: 15 July 2017 00:09 > To: Ruben Rodriguez <ru...@fsf.org> > Cc: ceph-users <ceph-users@lists.ceph.com> > Subject: Re: [ceph-users] R

Re: [ceph-users] RBD cache being filled up in small increases instead of 4MB

2017-07-14 Thread Gregory Farnum
On Fri, Jul 14, 2017 at 3:43 PM, Ruben Rodriguez wrote: > > I'm having an issue with small sequential reads (such as searching > through source code files, etc), and I found that multiple small reads > withing a 4MB boundary would fetch the same object from the OSD multiple >