EVA系列存储P6550和EVA8400的block size是多大？如何查看？

EVA controller firmware(VCS/XCS) divides each disk in smallest segement called Psegs(Physical Segements) of 2 Mbytes. Further 4 Psegs on the same vdisk amounts to an Rseg(Redundant Segement). Data is written according to the vraid level. For example in vraid5(4D+1P, contrary to RAID5) data is written on 5 psegs on separate hard drives. We do not have any control on size of Psegs. 

The data on disk is stored in 512 byte blocks, the data is striped in 512KB stripes with 4 data chunks of 128 KB each. If you are running VRAID 0 you write the basic data to 4 drives. VRAID 5 adds a 128 KB parity chunk that is written to a 5th disk. VRAID 1 duplicates each data chunk to a 2nd drive, so you are touching 8 drives.

A group of 16 stripes make up a total of 8 MB of data, and that is a Redundancy Segment (Rseg) that is written to a specific Redundancy Storage Set (RSS). The next 8 MB of data in the Vdisk is written out to the next RSS, and you go around all the RSSs in the Disk Group (since you have 128 Rsegs per GB of data)...

You can control the data block size when you write your file system to the Vdisk, but we don"t have any control over the stripe size, chunk size, or how the disks are assigned to the RSSs...

I got the above data from a technical presentation given by Ken Bates of StorageWorks engineering......