On Tue, Feb 8, 2011 at 12:09 PM, Allen Wittenauer <awittena...@linkedin.com>wrote:
> > On Feb 8, 2011, at 11:33 AM, Adam Phelps wrote: > > > On 2/7/11 2:06 PM, Jonathan Disher wrote: > >> Currently I have a 48 node cluster using Dell R710's with 12 disks - two > >> 250GB SATA drives in RAID1 for OS, and ten 1TB SATA disks as a JBOD > >> (mounted on /data/0 through /data/9) and listed separately in > >> hdfs-site.xml. It works... mostly. The big issues you will encounter is > >> losing a disk - the DataNode process will crash, and if you comment out > >> the affected drive, when you replace it you will have 9 disks full to N% > >> and one empty disk. > > > > If DataNode is going down after a single disk failure then you probably > haven't set dfs.datanode.failed.volumes.tolerated in hdfs-site.xml. You can > up that number to allow DataNode to tolerate dead drives. > > a) only if you have a version that supports it > > b) that only protects you on the DN side. The TT is, AFAIK, still > susceptible to drive failures. c) And it only works when the drive fails on read (HDFS-457), not on write (HDFS-1273).
