Hi Mike, Thanks for your quick reply.
On Wed, Sep 7, 2011 at 3:21 PM, Segel, Mike <[email protected]> wrote: > Hi, > > Ok, so you have a small cluster w raid drives... > First, raid isn't really a good idea. > > You want to replace the old raid drives w new 2TB drives in JBOD. > (Which is better.) > I'll do this then when I replace the disks. > > What percentage of your drives are filled? > The percentage is 53% on all nodes, so it should theoretically be possible to do. On the other hand I may be able to add another node into the mix which by then means that it will work. Thanks, -Marco > Assuming you have enough space on 2 of your DNs, you can decommission one, > run fsck and balancer to compensate for the lost blocks, then rebuild your > node. > Replace the drives w the 2TB as JBOD drives, bring the node back up. > Rebalance the cluster to get more of the data on the machine, and repeat > the process for the other nodes. > > HTH > > -Mike > > ________________________________________ > From: Marco Cadetg [[email protected]] > Sent: Wednesday, September 07, 2011 8:19 AM > To: [email protected] > Subject: best way to replace disks on a small cluster > > Hi there, > > Current situation: > 3 slaves with each two 320GB disks in RAID 1. All the disks show high read > errors and io throughput has gone below 5Mb/s without running any hadoop > job. (It looks like it will fall apart soon...) > > What is the best way to replace the bad disks? I may be able to add another > two machines into the mix. I can't / won't rebuild the RAID as my new disks > will be 2TB each, so I wouldn't like to use only 320GB of them. > > Is the best way to add two new nodes into the mix and then mark two other > machines to dfs.host.exclude. And after some time I can take them out??? > > Thanks for your help, > -Marco > > The information contained in this communication may be CONFIDENTIAL and is > intended only for the use of the recipient(s) named above. If you are not > the intended recipient, you are hereby notified that any dissemination, > distribution, or copying of this communication, or any of its contents, is > strictly prohibited. If you have received this communication in error, > please notify the sender and delete/destroy the original message and any > copy of it from your computer or paper files. >
