Re: RAID 5 performance problems

[Ezra Nugroho]

That looks like a slow build!
Mine is about 15 - 20M/sec.

Another observation I saw, I raided the raw devices instead of the
partitions; meaning my array is build from hde, hdg, hdi and hdk
as opposed to hde1, hdg1, hdi1 and hdk1.

On Thu, 2003-04-03 at 16:10, Jonathan Vardy wrote:
> you're right, it should be. When I was writing the original mail I had it
> running in degraded mode so I edited the values that /proc/mdstat gave me to
> match the array in normal mode. I forgot to make [_UUUU]  [UUUUU]. I'm
> currently rebuilding the array but it's taking some time...
> 
> md0 : active raid5 hdc1[5] hdk1[4] hdi1[3] hdg1[2] hde1[1]
>       468872704 blocks level 5, 128k chunk, algorithm 0 [5/4] [_UUUU]
>       [================>....]  recovery = 83.1% (97429504/117218176)
> finish=65.5min speed=5034K/sec
> 
> ----- Original Message -----
> From: "Andy Arvai" <[e-mail]>
> To: <[e-mail]>
> Cc: <[e-mail]>
> Sent: Thursday, April 03, 2003 9:49 PM
> Subject: Re: RAID 5 performance problems
> 
> 
> >
> > Shouldn't /proc/mdstat have [UUUUU] instead of [_UUUU]? Perhaps
> > this is running in degraded mode. Also, you have 'algorithm 0',
> > whereas my raid5 has 'algorithm 2', which is the left-symmetric
> > parity algorithm.
> >
> > Andy
> >
> > > cat /proc/mdstat gives:
> > >
> > > Personalities : [raid0] [raid5]
> > > read_ahead 1024 sectors
> > > md0 : active raid5 hdk1[4] hdi1[3] hdg1[2] hde1[1] hdc1[0]
> > > 468872704 blocks level 5, 128k chunk, algorithm 0 [5/5] [_UUUU]
> > > unused devices: <none>
> >
> >
> >
> > -
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