Hello, I have installed Fedora 7 on my system with the kernel 2.6.22.5-76.fc7.I run into a problem while copying to USB drives.I get a very poor copy speed.It starts off fast but later slows down to 1MB/s and even lower making the copying process painfully slow.I have even updated udev to latest version.What can I do to improve the speed?
Rohan Kulkarni escribió:
Hello, I have installed Fedora 7 on my system with the kernel 2.6.22.5-76.fc7.I run into a problem while copying to USB drives.I get a very poor copy speed.It starts off fast but later slows down to 1MB/s and even lower making the copying process painfully slow.I have even updated udev to latest version.What can I do to improve the speed?
First check your logs (/var/log/messages or dmesg) to see whats happening with the usb that makes it loss speed.
Somebody in the thread at some point said:
Hello, I have installed Fedora 7 on my system with the kernel 2.6.22.5-76.fc7.I run into a problem while copying to USB drives.I get a very poor copy speed.It starts off fast but later slows down to 1MB/s and even lower making the copying process painfully slow.I have even updated udev to latest version.What can I do to improve the speed?
Check if the thing is mounted with the "sync" option, if it is, use
# mount /dev/blah /mountpoint -oremount,rw
to get rid of it.
Also check if you are on USB 1.1...
# lsmod | grep ehci
-Andy
what is "sync"? and on using lsmod |grep ehci i get ehci_hcd 35405 0 what does this mean?
On 9/19/07, Andy Green andy@warmcat.com wrote:
Somebody in the thread at some point said:
Hello, I have installed Fedora 7 on my system with the kernel 2.6.22.5-76.fc7.I run into a problem while copying to USB drives.I get a very poor copy speed.It starts off fast but later slows down to 1MB/s and even lower making the copying process painfully slow.I have even updated udev to latest version.What can I do to improve the speed?
Check if the thing is mounted with the "sync" option, if it is, use
# mount /dev/blah /mountpoint -oremount,rw
to get rid of it.
Also check if you are on USB 1.1...
# lsmod | grep ehci
-Andy
-- fedora-list mailing list fedora-list@redhat.com To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
Somebody in the thread at some point said:
what is "sync"?
sync is an attribute of the mount that makes every little write get "sync"-ed to the actual hardware before going on. Without sync, it does a "lazy flush" of changed sectors to the actual device a few seconds (usually) after the first write to it.
Because it often happens the filesystem code or program you are using write to the same or nearly the same place several times in succession, it turns out that the lazy behaviour gives a huge speedup, since even if you wrote a 100 times to a given sector in a few seconds, only one actual commit of the sector takes place afterwards. With the "sync" mount option, you have to dumbly sit through 100 writes to the same place.
You have to take care to umount properly without sync, but it makes little difference since pulling the stick during writes with sync will create corruption anyway.
The
# mount
command on its own will show the options in force for each mounted filesystem.
and on using lsmod |grep ehci i get ehci_hcd 35405 0 what does this mean?
It means that USB 2 support is present, you should have a look in
# cat /proc/bus/usb/devices
for the stanza representing your USB device. For example one here looks like
T: Bus=05 Lev=01 Prnt=01 Port=05 Cnt=01 Dev#= 86 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=1516 ProdID=8628 Rev= 2.00 S: Manufacturer=memory S: Product=USB2.0 S: SerialNumber=3059 C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA I:* If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
The Spd=480 means it is wet up for USB2 "High Speed" that you would want.
-Andy
-
Andy Green -
Martin Marques -
Rohan Kulkarni