Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Lars Ellenberg wrote: > On Tue, Nov 20, 2007 at 11:34:17AM -0600, D. Dante Lorenso wrote: >> All, >> >> I'm interested in being able to share a file repository from 2 >> geographically remote locations and was interested in setting up DRBD to >> replicate between the 2 nodes. >> >> I'm using CentOS 5 for my platform. Does anyone have any documentation >> or howtos on what I need to do to set something like this up? > > what is your understanding of "Pirmary/Primary"? If I have 2 nodes, I'd like to use either node and have changes reflected on both. > do you want to use a cluster file system on top of that? > or do you want to have each site active for *its set* of shares, > and be the backup only for the respective other site's set? I'm exploring OCFS2, GFS, and Lustre in addition to my DRBD testing. > what does "geographically remote" mean in link latency and bandwidth? > 30 km FO dedicated 1Gbps low latency feeling for all practical purposes almost like a lan? > 3000 km 1Mbps flaky high latency bell wire? Regular internet bursting to 100 Mbps at each location, but likely to be throttled to just 1-10 Mbps for this purpose. > what is "a file repository"? what kind of files? Mostly media files audio/video/telecom. > why would you need synchronous replication, why would rsync not do? Currently rsync does the job. With synchronous replication, though, I'd be able to write a file locally then trigger a remote job to begin using that file immediately. Rsync works but is slow and we are syncing such a large number of files that the sync consumes a great deal of resources on both the sending and receiving sides. I've also been meaning to look into csync2. > what is your expected storage size? > what is your estimated average write rate? > what is you estimated peek write rate? I'm at 6 TB now. We have been doubling storage each 6-12 months. The 4 TB limit on DRBD makes me look at DRBD+, but the licensing costs there have us concerned. I see that the drbd.org site says: "Since DRBD-8.0.0 you can run both nodes in the primary role, enabling to mount a cluster file system (a physical parallel file system) one both nodes concurrently. Examples for such file systems are OCFS2 and GFS." I was hoping there was a nice tutorial/howto on specifically this type of Primary/Primary configuration. -- Dante