Re: Disk schedulers

[Roger Heflin <rogerheflin@gmail.com>]

Lukas Hejtmanek wrote:
> On Fri, Feb 15, 2008 at 03:42:58PM +0100, Jan Engelhardt wrote:
>> Also consider
>> - DMA (e.g. only UDMA2 selected)
>> - aging disk
> 
> it's not the case.
> 
> hdparm reports udma5 is used, if it is reliable with libata.
> 
> The disk is 3 months old, kernel does not report any errors. And it has never 
> been different.
> 

A new current ide/sata disk should do around 60mb/second, check the
min/max bps rate listed on the disk companies site, and divide by 8, and
take maybe 80% of that

Also you may consider using the -l option on the scp command to limit
its total usage.

This feature has been around at least 8 years (from 2.2) that high
levels of writes would significantly starve out reads, mainly because
you can queue up 1000's of writes, and a read, when the read
finishes there are another 1000's writes for the next read to
get in line behind, and wait, and this continues until the
writes stop.

                                 Roger