Re: limits on raid

2007-06-21 Thread David Greaves
Neil Brown wrote: This isn't quite right. Thanks :) Firstly, it is mdadm which decided to make one drive a 'spare' for raid5, not the kernel. Secondly, it only applies to raid5, not raid6 or raid1 or raid10. For raid6, the initial resync (just like the resync after an unclean shutdown)

Re: limits on raid

2007-06-21 Thread Mark Lord
[EMAIL PROTECTED] wrote: On Thu, 21 Jun 2007, David Chinner wrote: On Thu, Jun 21, 2007 at 12:56:44PM +1000, Neil Brown wrote: I have that - apparently naive - idea that drives use strong checksum, and will never return bad data, only good data or an error. If this isn't right, then it

Re: limits on raid

2007-06-21 Thread Nix
On 21 Jun 2007, Neil Brown stated: I have that - apparently naive - idea that drives use strong checksum, and will never return bad data, only good data or an error. If this isn't right, then it would really help to understand what the cause of other failures are before working out how to

Re: Software based SATA RAID-5 expandable arrays?

2007-06-21 Thread Richard Scobie
Michael wrote: Thank you; Not that I want to, but where did you find a SATA PCI card that fit 15 drives? Areca have a few - a range of PCI-X cards that do up to 24 SATA drives (ARC-1170) and PCI-e up to 24 drives (ARC-1280). Regards, Richard - To unsubscribe from this list: send the line

Re: limits on raid

2007-06-21 Thread Bill Davidsen
I didn't get a comment on my suggestion for a quick and dirty fix for -assume-clean issues... Bill Davidsen wrote: Neil Brown wrote: On Thursday June 14, [EMAIL PROTECTED] wrote: it's now churning away 'rebuilding' the brand new array. a few questions/thoughts. why does it need to do a

Re: stripe_cache_size and performance

2007-06-21 Thread Jon Nelson
On Thu, 21 Jun 2007, Raz wrote: What is your raid configuration ? Please note that the stripe_cache_size is acting as a bottle neck in some cases. Well, it's 3x SATA drives in raid5. 320G drives each, and I'm using a 314G partition from each disk (the rest of the space is quiescent). On