Tim Nelson wrote:
to or higher than the limit. Is this limit arbitrary? Based on detected system specs? Limitation of mdadm itself?
From the docs..
http://www.mjmwired.net/kernel/Documentation/md.txt
453 sync_speed_min 454 sync_speed_max 455 This are similar to /proc/sys/dev/raid/speed_limit_{min,max} 456 however they only apply to the particular array. 457 If no value has been written to these, of if the word 'system' 458 is written, then the system-wide value is used. If a value, 459 in kibibytes-per-second is written, then it is used. 460 When the files are read, they show the currently active value 461 followed by "(local)" or "(system)" depending on whether it is 462 a locally set or system-wide value.
Much higher end systems probably aren't running software raid in any case. I can't imagine using it myself for more than a few disks, the inconvenience alone of having to worry about keeping boot records intact or manually re-syncing is enough to keep me on hardware raid, which hasn't really ever let me down over several hundred controllers over the past many years(I only use good controllers though).
nate