Hi all,
I was recently charged with configuring a new fairly large (24x3TB disks) fileserver for my group. I think I know mostly what I want to do with it, but I did have two questions, at least one of which is directly related to CentOS.
1) The controller node has two 90GB SSDs that I plan to use as a bootable RAID1 system disk. What is the preferred method for laying out the RAID array? I found this document on the wiki:
http://wiki.centos.org/HowTos/Install_On_Partitionable_RAID1
But that seems like it's somewhat nonstandard. From what I've read in the RHEL6 docs, it seems like the anaconda-supported RAID1 install is the alternative that the wiki suggests, partitioning the disk and adding the partitions to the appropriate RAID1 array.
So, is there a happy medium, where anaconda more directly supports the partitionable RAID1 install method? And if so, what are the drawbacks to such a configuration? The wiki talks about the advantages but doesn't really address any disadvantages.
2) With large arrays you often hear about "aligning the filesystem to the disk". Is there a fairly standard way (I hope using only CentOS tools) of going about this? Are the various mkfs tools smart enough to figure out how an array is aligned on its own, or is sysadmin intervention required on such large arrays? (If it helps any, the disk array is backed by a 3ware 9750 controller. I have not yet decided how many disks I will use in the array, if that influences the alignment.)
--keith