Re: raid5 software vs hardware: parity calculations?

2007-01-13 Thread dean gaudet
On Sat, 13 Jan 2007, Robin Bowes wrote: > Bill Davidsen wrote: > > > > There have been several recent threads on the list regarding software > > RAID-5 performance. The reference might be updated to reflect the poor > > write performance of RAID-5 until/unless significant tuning is done. > > Read

Re: FailSpare event?

2007-01-13 Thread Nix
On 13 Jan 2007, [EMAIL PROTECTED] uttered the following: > On 12 Jan 2007, Ernst Herzberg told this: >> Then every about 60 sec 4 times >> >> event=SpareActive >> mddev=/dev/md3 > > I see exactly this on both my RAID-5 arrays, neither of which have any > spare device --- nor have any active device

Re: FailSpare event?

2007-01-13 Thread Nix
On 13 Jan 2007, [EMAIL PROTECTED] spake thusly: > On 12 Jan 2007, Ernst Herzberg told this: >> Then every about 60 sec 4 times >> >> event=SpareActive >> mddev=/dev/md3 > > I see exactly this on both my RAID-5 arrays, neither of which have any > spare device --- nor have any active devices transit

Re: raid5 software vs hardware: parity calculations?

2007-01-13 Thread Robin Bowes
Bill Davidsen wrote: > > There have been several recent threads on the list regarding software > RAID-5 performance. The reference might be updated to reflect the poor > write performance of RAID-5 until/unless significant tuning is done. > Read that as tuning obscure parameters and throwing a lot

Re: FailSpare event?

2007-01-13 Thread Mike
On Fri, 12 Jan 2007, Neil Brown might have said: > On Thursday January 11, [EMAIL PROTECTED] wrote: > > Can someone tell me what this means please? I just received this in > > an email from one of my servers: > > > > > > > > A FailSpare event had been detected on md device /dev/md2. > > >

Re: FailSpare event?

2007-01-13 Thread Nix
On 12 Jan 2007, Ernst Herzberg told this: > Then every about 60 sec 4 times > > event=SpareActive > mddev=/dev/md3 I see exactly this on both my RAID-5 arrays, neither of which have any spare device --- nor have any active devices transitioned to spare (which is what that event is actually suppose

Re: raid5 software vs hardware: parity calculations?

2007-01-13 Thread Bill Davidsen
Dan Williams wrote: On 1/12/07, James Ralston <[EMAIL PROTECTED]> wrote: On 2007-01-12 at 09:39-08 dean gaudet <[EMAIL PROTECTED]> wrote: > On Thu, 11 Jan 2007, James Ralston wrote: > > > I'm having a discussion with a coworker concerning the cost of > > md's raid5 implementation versus hardwar

Re: Linux Software RAID 5 Performance Optimizations: 2.6.19.1: (211MB/s read & 195MB/s write)

2007-01-13 Thread Justin Piszcz
On Sat, 13 Jan 2007, Al Boldi wrote: > Justin Piszcz wrote: > > On Sat, 13 Jan 2007, Al Boldi wrote: > > > Justin Piszcz wrote: > > > > Btw, max sectors did improve my performance a little bit but > > > > stripe_cache+read_ahead were the main optimizations that made > > > > everything go faster

Re: raid5 software vs hardware: parity calculations?

2007-01-13 Thread Dan Williams
On 1/12/07, James Ralston <[EMAIL PROTECTED]> wrote: On 2007-01-12 at 09:39-08 dean gaudet <[EMAIL PROTECTED]> wrote: > On Thu, 11 Jan 2007, James Ralston wrote: > > > I'm having a discussion with a coworker concerning the cost of > > md's raid5 implementation versus hardware raid5 implementatio