On Fri, Jun 29, 2012 at 11:55 AM, Gregory Farnum <greg@xxxxxxxxxxx> wrote: > So right now you're using the Ceph filesystem, rather than RBD, right? Right, CephFS. I'm actually not even very clear on what RBD is, and how one might use it, but I'm sure I'll understand that in the fullness of time. I came to Ceph from a background of wanting to replace my primary RAID array with a RAIM (redundant array of inexpensive machines) cluster, and a co-worker suggested Ceph as a possibility. > What processes do you have running on which machines/VMs? What's the > CPU usage on the ceph-mds process? I have four VMs running Debian testing, with a dom0 on a recent 6-core AMD cpu (I forget which one). Each VM has two virtual cores, 1GB of RAM, and a 500GB virtual disk partition formatted with btrfs, used for both data and journal. These are somewhat smaller than recommended, but in the right ballpark, and the filesystem has so far not been used to store any significant amount of data. (Mostly just bonnie tests.) All four VMs are running OSD, the first three are running MON, and the first two MDS. I mostly watch top on the first machine (if there's a better tool for watching a cluster, please let me know), and it shows the majority of the CPU time in wait, with the Ceph jobs popping up from time to time with a fraction of a percent, sometimes up into single digits. It's also not uncommon to see a lot of idle time. When I get some time I'm going to wrap some sort of collector around the log files and feed the data into OpenTSDB. > And a warning: the filesystem, while nifty, is not yet > production-ready — it works great for some use cases but there are > some serious known bugs that aren't very hard to trigger, as we've > been doing a lot of QA on RADOS and its associated systems (which the > filesystem depends on) at the expense of the filesystem itself. Good to know. For now I'm just playing, but I eventually want to have a distributed filesystem that I can use. I'm curious to see how Ceph does when deployed on real hardware, which I expect to have in the next couple weeks. Very simple stuff compared to what I see others on the list discussing: a few dual core Atom systems with 1TB of drive and 4GB of RAM each, all on a 1Gb switch. Brian. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
