[CentOS] slow usb hard disk performance.

Mon Dec 5 15:41:36 UTC 2005
Robert <kerplop at sbcglobal.net>

Peter Farrow wrote:

> Dear All,
>
> I tried a USB2 Maxtor One touch II external hard disk on a couple of 
> my Centos 4.2 boxes and found it initiallised the SCSI subsystem ok 
> and added device "sda".  But the performance is miserable, yet the 
> same hardware running XP the performance is satisfactory.
>
> HDPARM gives results varying from 120k/sec to , at its peak 4.75M/s on 
> a USB 2 machine, still very poor by any stretch.
>
> On a twin CPU USB 1 machine it give a steady 1M/sec, which is 
> consistently slow, which is better than erratically slow ( :-) )
>
> Still dog slow, wondered if anyone has seen this, and wondered if the 
> firewire interface would be better?  (I need to get a cable to try this).

I back up weekly to a Maxtor OneTouch (original) USB2-connected hard 
drive. This happens while I sleep but it looks like last Wednesday 
morning, it took 36 minutes to to copy 19GB.

    [root at mavis ~]# du -hs /media/OTOT/2005-11-30
    19G     /media/OTOT/2005-11-30
    [root at mavis ~]#

    [rj at mavis ~]$ cat backup_progress_2005-11-30
    Wed Nov 30 02:02:07 CST 2005 Removing /media/OTOT/2005-11-09
    Backup to /media/OTOT/2005-11-30 Started at Wed Nov 30 02:06:13 CST 2005
    Wed Nov 30 02:06:14 CST 2005 Completed: /bin
    Wed Nov 30 02:06:15 CST 2005 Completed: /boot
    <snip>
    Wed Nov 30 02:42:14 CST 2005 Completed: /var
    Filesystem           1K-blocks      Used Available Use% Mounted on
    /dev/sdb2            152206916 132579164  11896072  92% /media/OTOT
    /dev/sdb2 successfully  unmounted from /media/OTOT
    All Finished at Wed Nov 30 02:42:14 CST 2005
                                    

Looks like that averages out to about 8.8MB/sec
I'm running an Athlon 2600+, 2GHz, 512MB on an ASUS A7N8X.
I hope this helps.