On Thu, 21 Jun 2007 08:30:20 -0400 "John Drescher" <[EMAIL PROTECTED]> wrote:
> > > > I know that RAID5 is very appealing 'cause you end with 'a lot of usable > > disk space' but, I always discourage to use it. > > > > Each chunk of data to be written to disk is divided in Numer of physical > > RAID disks writes - 1 plus another write to store CRC on to the remaining > > disk ( the CRC chunk is written in a round-robin model using all RAID disks > > ). For write changed data, the RAID logic must locate where the data was, > > rewrite it and calculate the changes to the parity to reflect the changes > > > > Another important point is the time spend on rebuild a previously failed > > disk ( data is not copied from antoher disk, is regenerated using the data > > in CRC chunks ) > > > > And another tip, If fails 2 disks, good by data, must restore from backup > > > > How about raid 6? With raid 6 you can loose 2 disks and you loose nothing. I > have around 10TB mostly on raid 6 using 250GB and 330 GB SATA drives and > they work great. I have had to replace a disk from time to time but I have > never had 2 go bad at once. > > Always try to use any more 'friendly' RAID as RAID1 / RAID10 > > > > But then you throw away 1/2 the space. We can argue/discuss this until we're blue in the face but IMHO RAID10 is the way to go. Better performance, better redundancy, and better reliability. And increasingly I want to do in in software rather than hardware. -- Best regards, Ken Gunderson GPG Key -- 9F5179FD "Never hold discussions with the monkey when the organ grinder is in the room." - Sir Winston Churchill ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
