Hello List, I hope, I don't ask a question that is answered already, but if so, pointing to the solution would be nice. Although the Subject is problably misleading a bit, that is essentially my problem (as far as I understand). Is it possible to apply OSDs directly to a root to circumvent a pool from using all OSDs on a host, or can I somewhere "fix" the hostname, with which the OSDs are started (for each OSD seperately)? This should be a non-volatile configuration. The scenario: I have build a cluster of 3 Proxmox Virtualisation Hosts (at the moment). I use Ceph to provide the distributed storage. There is good documentation to build the ceph cluster on Proxmox hosts. Each system has 4 conventional HDDs and 2 SSDs (one for the OS, and another was planed for the journal). I came across cache pools then. Now I wanted to use the second SSD becoming an OSD for a cache pool. I set up 5 OSDs (4x HDD and 1xSSD) on each host. A default CRUSHmap was generated with every OSD set to be part of the node it was on. However, in order to create a second pool, I had to separate the SSDs from the other drives. I edited the CRUSHmap so that they would appear to be on different hosts (which are not existent), and set up a second root and ruleset for what to become the cache pool. As far as I could see, this worked well. Setting up the second pool and adding it as a tier to the original storage as well as setting it to cache-mode worked to. Using this setup as the backend storage for the VMs, these VMs seem really fast on disk IO, so I guess, it all did, what it should. The Problem was, that after reboot (or at any event that starts the OSD deamons automatically), the SSD-OSDs are startet within the original host (which makes sense) and so they appear on the normal storage-pool tier rather than the cache-pool, which was then in a degraded state. Other than manually reset the CRUSHmap after any failed SSD or reboot or any event that causes the OSD deamons to restart, I see nothing to fix that. Thanks for your answers in advance, Christian Doering -- Christian D?ring christian.doering at comfortticket.de <mailto:christian.doering at comfortticket.de> comfortticket Karten- und Vertriebsservices GmbH Deichstr. 21 20459 Hamburg Tel. +49-40-696505-55 Fax. +49-40-696505-90 Web. http://www.comfortticket.de Gesch?ftsf?hrer: Bj?rn Schlesselmann Registergericht: Amtsgericht Hamburg HRB89224 Follow us on Facebook <https://www.facebook.com/pages/comfortticketde/243568222351949> Twitter <http://twitter.com/comfortticketde> Google+ <https://plus.google.com/u/0/b/106127096037175048393/106127096037175048393> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140731/bb5e0c80/attachment.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: djijifbj.png Type: image/png Size: 246 bytes Desc: not available URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140731/bb5e0c80/attachment.png> -------------- next part -------------- A non-text attachment was scrubbed... Name: debhebah.png Type: image/png Size: 457 bytes Desc: not available URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140731/bb5e0c80/attachment-0001.png> -------------- next part -------------- A non-text attachment was scrubbed... Name: bcdcgehd.gif Type: image/gif Size: 926 bytes Desc: not available URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140731/bb5e0c80/attachment.gif>