topic Re: cp command slow after install new kernel. in Operating System - Linux

cp command slow after install new kernel.

klemerS — Mon, 27 Feb 2006 14:22:54 GMT

Hi.

I got dl380 connected to eva5000. each day
i copy data from mt ocfs filesystem to ext3:
cp -r --o_direct ...

The cp takes about 30 min for 50gb. After I
update my kernel from 2.4.21-27 to 2.4.21-37
its take 90min thae same copy.

even regular "cp" tkae twice the time.

I checked few times by reloading the kernels
to insure that i dont make any mistake?

its very strange!!

Any Idea?????

Thanks.

Re: cp command slow after install new kernel.

Eric Singer — Mon, 27 Feb 2006 16:03:20 GMT

Have you reloaded the most current modules for the HBA(s)? When you change kernels the modules that came with the kernel will be loaded which are normally not very current.

Re: cp command slow after install new kernel.

Alan_152 — Tue, 28 Feb 2006 10:43:31 GMT

check your hba drivers, and make sure that your setup on the eva is optimized and not opening extra ports (a problem I'm having right now is that for every LUN I set up on the eva, it creates 4 /dev/sd? devices on my box -- apparently this is a known problem).

Re: cp command slow after install new kernel.

klemerS — Tue, 28 Feb 2006 13:45:39 GMT

Thanks for your replays!

I will check the HBA driver.

I dont think that the eva ports is A problem

since the cp command work well with kernel

2.4.21-27

Meanwhile i am working with the old kernel.

Shalom.

Re: cp command slow after install new kernel.

Erez Kirson — Tue, 28 Feb 2006 15:10:05 GMT

Hi,

I would recommend using "tar" for large copies.
you will see a major preformence improvement

Erez

Re: cp command slow after install new kernel.

klemerS — Wed, 01 Mar 2006 01:44:05 GMT

Hi.

About tar... Can i use tar to copy files

from ocfs filesystem to ext3 ????

with cp i use the --o_direct option.

Shalom.

Re: cp command slow after install new kernel.

Vitaly Karasik_1 — Wed, 01 Mar 2006 05:18:44 GMT

It may be some problem with a LBA and/or NIC drivers.
Try to load *old* kernel and check which LBA/NIC drivers it uses.

Rgds,
Vitaly

Re: cp command slow after install new kernel.

Vitaly Karasik_1 — Wed, 01 Mar 2006 05:22:18 GMT

BTW, don't forget about assigning points!
(0 points for answers to 27 questions isn't too much... )

Re: cp command slow after install new kernel.

Alan_152 — Wed, 01 Mar 2006 10:27:22 GMT

http://amath.colorado.edu/computing/software/man/tar.html

Speicifically,

Create an archive (bundle together a bunch of files+directories into a single file):

tar cvf archivefile.tar file1 file2 subdir1 subdir2

Re: cp command slow after install new kernel.

klemerS — Mon, 06 Mar 2006 15:21:29 GMT

Hi.

I did not have the chance to check the problem yet.

but i think that i will install test machine
with RHES 3.0 U6 & see if i get the same
symptoms.

Shalom.

Re: cp command slow after install new kernel.

klemerS — Mon, 06 Mar 2006 15:34:45 GMT

Hi Alan.

i download the tar rpm which support
the direct_io & i will check this too.

Thanks.

Re: cp command slow after install new kernel.

Alan_152 — Mon, 06 Mar 2006 16:46:50 GMT

You really shouldn't need to downloan any rpms for tar, as tar is native to just about every *nix version every made (or at least since 1970).