extremely slow copy speed (50k/s)

[vinícius mota]

Hello everybody,

I have this very weird problem, that I have noticed some 2 or 3 days ago,
and of a kind I have never heard before. I made a post in fedora.forum (
http://forums.fedoraforum.org/showthread.php?t=259047), but get no awswer
since then, and now I have been advised to post here too.

Briefly, the problem is that the copy speed between the partition in which I
am running my Fedora and another partition where I store backup data is now
50K/s, which is extremely slow by any standart (it has been usually around
10M/s, almost 200 times faster). This is for exemple much lower than the
copy speed between my computers in my lab and home, via internet, which is
obviously absurd. I have been using Fedora 64 for many years, and this is
the first time I have a problem that I cannot solve by myself, which is very
frustrating. Let me proceed with the details.

My laptop is a HP Pavillion Dv7 2080 ep, in which I have two disks of 250G
each. One of the disks is partitioned between two operational systems,
Fedora 14 64 and Windows 7 64, and the other disk contains the above
referred partition where I store my backups (I call it backup disk). The
problem happens when I try to copy anything from my home in Fedora to the
backup disk, and also when, while using fedora, I try to move data within
the backup disk itself. I first thought it could be a hardware problem in
the backup disk. Then I login into the windows and made a copy of some AVI
files (3G approx) to the backup disk, which went normally, within a few
seconds, thus eliminating this possibility. I move data within the backup
iself disk using windows also without any problem. I try therefore to make
the inverse process, a copy from the backup disk into my home folder in
Fedora. It went normally, copying 4 G also within few seconds, actually with
an excellent speed of 50M/s.

After searching in google, I saw some people also complaining of slow copy
speed (although they had 7M/s, more than 100 times faster than what I have
now), and one cause could be that the source file system (in my case the
Fedora home folder) would be near its full capacity. I therefore eliminate
everything that I could, around 15G, and now I have like 20G of free disk
space, which I think is more than enough for everything. The problem,
however, persists. Some people also said that it could be the type of files
and/or amount of data. I therefore tried several kinds of files (from raw
data files to AVI and RMVB regular video files), and several amounts of data
(from single files with a few Megas to folders with 20G) and in all cases I
had the same unacceptably low copy speed of 50K/s. Another possibility was
checking the disk via the command line "hdparm", but since I am not an
expert I could not identify anything wrong from its output. Anyway, here it
is for both disks (/dev/sda and /dev/sdb):

[root@localhost ~]# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   11320 MB in  1.99 seconds = 5681.38 MB/sec
 Timing buffered disk reads:  204 MB in  3.02 seconds =  67.52 MB/sec

[root@localhost ~]# hdparm /dev/sda

/dev/sda:
 multcount     =  0 (off)
 IO_support    =  1 (32-bit)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 30401/255/63, sectors = 488397168, start = 0



[root@localhost ~]# hdparm -Tt /dev/sdb

/dev/sdb:
 Timing cached reads:   12044 MB in  1.99 seconds = 6046.50 MB/sec
 Timing buffered disk reads:  206 MB in  3.00 seconds =  68.57 MB/sec

[root@localhost ~]# hdparm /dev/sdb

/dev/sdb:
 multcount     =  0 (off)
 IO_support    =  1 (32-bit)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 30401/255/63, sectors = 488397168, start = 0



It seems therefore to be a problem in the software, caused by the updates,
since until 10 days ago it was everything ok. However, I usually make the
updates whenever they appear but make my backups much less frequently.
Therefore I don't know for sure what has changed in Fedora through the
updates since the last backup I made, when everything was working fine.

He is the line of my /etc/fstab file which defines my backup disk, with the
label common


LABEL=common            /home/vinicius/Desktop/common  ntfs
auto,user,sync  0 0


Thank you all for your attention and please apologise me for the huge text.