raid10 far layout outperforms offset at writing? (was: Help with chunksize on raid10 -p o3 array)

Peter Rabbitson wrote: I have been trying to figure out the best chunk size for raid10 before migrating my server to it (currently raid1). I am looking at 3 offset stripes, as I want to have two drive failure redundancy, and offset striping is said to have the best write performance, with read

Re: Help with chunksize on raid10 -p o3 array

Richard Scobie wrote: Peter Rabbitson wrote: Is this anywhere near the top of the todo list, or for now raid10 users are bound to a maximum read speed of a two drive combination? I have not done any testing with the md native RAID10 implementations, so perhaps there are some other advantages

Re: Help with chunksize on raid10 -p o3 array

Peter Rabbitson wrote: Is this anywhere near the top of the todo list, or for now raid10 users are bound to a maximum read speed of a two drive combination? I have not done any testing with the md native RAID10 implementations, so perhaps there are some other advantages, but have you tried se

Re: Help with chunksize on raid10 -p o3 array

Neil Brown wrote: The different block sizes in the reads will make very little difference to the results as the kernel will be doing read-ahead for you. If you want to really test throughput at different block sizes you need to insert random seeks. Neil, thank you for the time and effort to a

Re: Help with chunksize on raid10 -p o3 array

On Tuesday March 6, [EMAIL PROTECTED] wrote: > Hi, > I have been trying to figure out the best chunk size for raid10 before > migrating my server to it (currently raid1). I am looking at 3 offset > stripes, as I want to have two drive failure redundancy, and offset > striping is said to have the

Re: Help with chunksize on raid10 -p o3 array

Bill Davidsen wrote: Peter Rabbitson wrote: Hi, I have been trying to figure out the best chunk size for raid10 before By any chance did you remember to increase stripe_cache_size to match the chunk size? If not, there you go. At the end of /usr/src/linux/Documentation/md.txt it specifical

Re: Help with chunksize on raid10 -p o3 array

Peter Rabbitson wrote: Hi, I have been trying to figure out the best chunk size for raid10 before migrating my server to it (currently raid1). I am looking at 3 offset stripes, as I want to have two drive failure redundancy, and offset striping is said to have the best write performance, with