The issue is that my MB is not doing JBOD :( I have RAID only possible, and I'm fighting for the last 48h and still not able to make it work... That's why I'm thinking about using dfs.data.dir instead.
I have 1 drive per node so far and need to move to 2 to reduce WIO. What will be better with JBOD against dfs.data.dir? I have done some tests JBOD vs LVM and did not find any pros for JBOD so far. JM 2013/2/10, Michael Katzenellenbogen <[email protected]>: > One thought comes to mind: disk failure. In the event a disk goes bad, > then with RAID0, you just lost your entire array. With JBOD, you lost > one disk. > > -Michael > > On Feb 10, 2013, at 8:58 PM, Jean-Marc Spaggiari > <[email protected]> wrote: > >> Hi, >> >> I have a quick question regarding RAID0 performances vs multiple >> dfs.data.dir entries. >> >> Let's say I have 2 x 2TB drives. >> >> I can configure them as 2 separate drives mounted on 2 folders and >> assignes to hadoop using dfs.data.dir. Or I can mount the 2 drives >> with RAID0 and assigned them as a single folder to dfs.data.dir. >> >> With RAID0, the reads and writes are going to be spread over the 2 >> disks. This is significantly increasing the speed. But if I put 2 >> entries in dfs.data.dir, hadoop is going to spread over those 2 >> directories too, and at the end, ths results should the same, no? >> >> Any experience/advice/results to share? >> >> Thanks, >> >> JM >
