Rsyncing to USB Hard Drive unbelievably slow! - Raspberry Pi Forums

i used take backups of servers using centos server usb hard drive. computer died, did another. thought invest in pi , use instead. set , seemed work ok. connected hard drive powered usb hub read pi wont able power itself.

when ran trust backup sript use every day 4 years, seems unbelievably slow. ran test on drive pi, ran test o drive centos on mac using virtualbox. these results:

pi

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root@raspberrypi:~# hdparm -tt /dev/sda2  /dev/sda2:  timing cached reads:     2 mb in  4.31 seconds = 475.56 kb/sec  timing buffered disk reads:   2 mb in  4.13 seconds = 496.21 kb/sec

mac

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  [root@localhost ~]# hdparm -tt /dev/sdb2  /dev/sdb2:  timing cached reads:   5462 mb in  2.00 seconds = 2731.51 mb/sec  timing buffered disk reads:  24 mb in  3.12 seconds =   7.69 mb/sec

can see, pi extremely slow.

wondered if has ideas. pi slow, there setting adjust it, or usb hub absolutely terrible?

thanks

further investigation leads me believe usb hub. quite old. connected drive through hub when using centos on mac virtualbox. no pi involved. , terrible results that:

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[root@localhost ~]# hdparm -tt /dev/sdb2  /dev/sdb2:  timing cached reads: 2 mb in 72.78 seconds =  28.14 kb/sec  timing buffered disk reads:   2 mb in 16.14 seconds = 126.86 kb/sec

know in usb hub maximise throughput? because usb 1 , need usb 2 or 3 (i think 2 pi doesnt use 3?). else? dont want invest in usb hub , still have slow speeds.

guess must common issue due not being able power usb drive using pi, , needing powered hub?

thanks

raspberrypi