[CentOS] RAID 6 - opinions

Thu Apr 11 23:24:02 UTC 2013
David C. Miller <millerdc at fusion.gat.com>

----- Original Message -----
> From: "Reindl Harald" <h.reindl at thelounge.net>
> To: "CentOS mailing list" <centos at centos.org>
> Cc: "David C. Miller" <millerdc at fusion.gat.com>
> Sent: Thursday, April 11, 2013 4:17:18 PM
> Subject: Re: [CentOS] RAID 6 - opinions
> 
> 
> 
> Am 12.04.2013 01:13, schrieb David C. Miller:
> > dd if=/dev/zero of=/backup/5GB.img count=5000 bs=1M
> > 5000+0 records in
> > 5000+0 records out
> > 5242880000 bytes (5.2 GB) copied, 10.8293 s, 484 MB/s
> 
> aha, you have 16 GB RAM, write 5 GB to the disk which
> is easily buffered into RAM and think this measures
> anything?
> 
> do the same with 32 GB instead 5 GB
> 
> 
Good call, I did not even think about that. Here is a 31GB file write. 

dd if=/dev/zero of=/backup/30GB.img count=30000 bs=1M
30000+0 records in
30000+0 records out
31457280000 bytes (31 GB) copied, 78.041 s, 403 MB/s

David.