Hello, Just to update the list, as Jim suggested, I couldn't find away to stop the RAID array from initialising during kickstart. However, after a little hunting with google I found a way to throttle back the amount of disk IO to use for the rebuild. This is in : /proc/sys/dev/raid/speed_limit_max /proc/sys/dev/raid/speed_limit_min I reduced both of these down as part of my %pre section and now the kickstart runs at a reasonable speed. Thanks for all your help, and appologies for the stupidly long email disclamer, I have no control over it :-( Paul This e-mail is the property of Quadriga Worldwide Ltd The message (and any associated files) is intended only for the use of the individual or entity to which it is addressed and may contain information that is confidential, subject to copyright or constitutes a trade secret. If you are not the intended recipient you are hereby notified that any dissemination, copying or distribution of this message, or files associated with this message, is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer. Messages sent to and from us may be monitored. Internet communications cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. Therefore, we do not accept responsibility for any errors or omissions that are present in this message, or any attachment, that have arisen as a result of e-mail transmission. If verification is required, please request a hard-copy version. Any views or opinions presented are solely those of the author and do not necessarily represent those of the company.