On Oct 17, 2007 15:35 -0400, Brock Palen wrote: > We are doing some testing, > > For a OST with a xserve raid connected to linux, is it better to not > have a partition table > > mkfs.lustre /dev/sda > > or to have a partition? > fdisk /dev/sda > mkfs.lustre /dev/sda1
For RAID 5/6 devices we recommend NOT having a partition table. The reason is that the partition table offsets the data partitions by a small amount (512 bytes usually) and this causes writes to span multiple RAID chunks and unnecessary read-modify-write activity. For best performance, pick a RAID chunk size that divides evenly into 1MB (e.g. 4 or 8 data disks + parity). The ldiskfs mballoc code works to align the allocation with the RAID chunk size for best performance. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
