Hard disk bottle neck.

[Diego F. Arias R.]

First be shure your bottleneck are the hard drives.

On Sun, Sep 28, 2008 at 8:54 AM, Bill Moran <wmoran at potentialtech.com> wrote:
> "Danny Do" <danhdo at gmail.com> wrote:
>>
>> Hi guys,
>>
>> I have this problem for years but couldn't find a way to solve it.
>>
>> I have a file server handling large files from 1MByte to 1GByte.
>>
>> Server Info:
>> FreeBSD 6.2
>> Apache 2.2.9
>>
>> DELL PowerEdge 1850
>> 2GB RAM (only 184MB is active)
>> 6x300MB SCSI 10K RPM RAID5
>> Gigabit Ethernet Connection
>>
>> My server can output NO MORE than 60Mbps (read only).
>>
>> The bottle neck is the hard disk.
>
> What evidence do you have that the bottleneck is disk IO?  I've seen no
> evidence, only speculation.
>
> In addition to the advice of others, you may be able to just beef up the
> RAM.  2G isn't much these days.  If you've got 200M active, you've got
> about 1.8G available to cache files.  If you have repeated access of the
> same file, the OS can cache that file data and not even use the disk, but
> it can only do that if it has enough RAM to work with.  You need to get
> your facts straight, though.  According to the specs you've got above,
> you've only got 1.5G of disk.  I expect you meant 300G disks.
>
> You could also add disks in a RAID 10, which is generally faster than
> RAID 5, or move to 15,000 RPM disks.  I think you might be surprised how
> much adding some RAM will help, though, unless your access patterns are
> very random, RAM should speed up the access of popular data significantly.
>
> --
> Bill Moran
> http://www.potentialtech.com
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-- 
mmm, interesante.....