On Mon, 12 Oct 1998, Benjamin de los Angeles Jr. wrote:
> Basing from the short documentation included in raidtools -- is the chunk
> size used in writing AND reading data from a RAID device? If it is,
> then in a RAID0 setup, it would be better if I have smaller chunks i.e.
> 8k, that is if I have smaller sizes of data, ideally 8k * n size, where n
> is the number of RAID'D disks. The reverse is true if I have bigger
> files, they need a bigger chunk size.
>
> For RAID1, the bigger the chunk size the better, unless all data are too
> small for the chunk, which is inefficient.
For RAID levels 0, 4 and 5 (the various "striping" RAID levels, it depends
upon your goal.
If you want to get maximum throughput for a single process by using all your
spindles in parallel for each read or write operation, then you want a small
chunk size.
If, on the other hand, you want to randomize your spindle load (i.e. ideally
have a different process reading or writing to/from each spindle), then you
want a large chunk size. Some people also call this overlapped read and
write.
I don't think I understand how the concept of chunk size applies to RAID 1.
Since it's supposed to fill one partition and then another, I don't see
where chunk size comes into it... could just be me. :-)
-Andy
Global Auctions
http://www.globalauctions.com
