[CentOS] slow usb hard disk performance.
Robert
kerplop at sbcglobal.net
Mon Dec 5 18:04:53 UTC 2005
Bryan J. Smith wrote:
>Robert <kerplop at sbcglobal.net> wrote:
>
>
>> for dir in bin boot etc home initrd lib lost+found misc
>>opt root \
>> sbin selinux srv tftpboot \
>> usr var ; do
>> find /$dir -depth -print0 | cpio --null -pmd $UD/$DT
>> echo `date` Completed: /$dir >>$PF
>> done
>>
>>
>
>That's not a good benchmark. You're adding the overhead of
>inode/tree traversal and all sorts of other factors. You're
>easily cutting performance by 2-3x over.
>
>Since USB 2.0 EHCI is capable of only 60MBps (480Mbps)
>theoretical, and Intel openly admits that only 30MBps is
>realistic, 8.8MBps is not unreasonable for this command.
>
>Try a "raw" dd from /dev/zero, that is at least 2x your
>memory:
> dd if=/dev/zero of=(some file) bs=8M count=1000
>
>Or consider a bonnie benchmark.
>
>
I wasn't complaining, Bryan, simply responding. Actually, having moved
from a DAT-2 drive to the USB-connected disk, I'm happy as a pig in sh*t
to be able to backup the whole thing unattended and have a reasonable
expectation that the resulting wad of crud is good! (I'm still gonna
burn /boot, /root, /home and /etc to DVD once a month, though.)
Have a great day!
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.centos.org/pipermail/centos/attachments/20051205/9db01183/attachment.html>
More information about the CentOS
mailing list