On Monday May 7, rabbit@xxxxxxxxx wrote: > Neil Brown wrote: > > On Friday May 4, davidsen@xxxxxxx wrote: > >> Peter Rabbitson wrote: > >>> Hi, > >>> > >>> I asked this question back in march but received no answers, so here it > >>> goes again. Is it safe to replace raid1 with raid10 where the amount of > >>> disks is equal to the amount of far/near/offset copies? I understand it > >>> has the downside of not being a bit-by-bit mirror of a plain filesystem. > >>> Are there any other caveats? > >>> > > > > To answer the original question, I assume you mean "replace" as in > > "backup, create new array, then restore". > > You will get different performance characteristics. Whether they > > better suit your needs or not will depend largely on your needs. > > Hi Neil, > Yes I meant take an existing 2 drive raid1 array (non bootable data) and > put a raid10 array in its place. All my testing indicates that I get the > same write performance but nearly double the read speed (due to > interleaving I guess). It seemed to good to be true, thus I am asking > the question. Could you elaborate on your last sentence? Are there > downsides I could not think of? Thank you! I would have thought that you need "far" or "offset" to improve read performance, and they tend to hurt write performance (though I haven't really measured "offset" much). What layout are you using? NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
