Coda File System

Re: write speed

From: Vojtech Moravek <vojtech.moravek_at_cz.tiscali.com>
Date: 30 Jan 2003 15:39:44 +0100
Yesteraday i wrote some problems with slow write operations. I made some
tests and results is:

When coda run on computers which have only one cpu. Everything is cool.
When is CODA installed on twoCPUs computer I have problem with write
operations.. more describes are bellow:

There are thee figures how Coda was tested and bellow is copy&pase how i
set up Vice and Venus.

I can give account to all computers for testing, because i don't know
where is problem and what i can do yet :(

Best Regard 
Vojtech Moravek


***********************************

Figure 1 - everything slow

This is deadly combinations :) when i try write by VENUS from SCM server
or VENUS on CLIENT all write operations are slowly..

SCM -Server
------
Comp: eServer 345 2x Xeon + ibmRaid controller
OS: RedHat 8.0, kernel 2.4.18-14smp (default smp kernel) 


CLIENT -VENUS
--------
COMP: eServer 305
OS: RedHat 8.0, kernel 2.4.18-14 (default kernel) 


PERFORMANCE-write 1MB file
------------------------
VENUS-on-SCM
time dd if=/dev/zero of=/coda/server bs=1024 count=1024
real    0m33.700s
user    0m0.000s
sys     0m0.020s


VENUS-on-CLIENT
time dd if=/dev/zero of=/coda/server bs=1024 count=1024
real    0m18.425s
user    0m0.002s
sys     0m0.008s






******************************************
Figure 2 -

 Write from venus on  SCM is quick, from venus on other computer slow.
!!! Here is another kernel on SCM

SCM
------
Comp: eServer 345 2x Xeon + ibmRaid controller
OS: RedHat 8.0, kernel 2.4.18-14 (default kernel) 

CLIENT -VENUS
--------
COMP: eServer 305
OS: RedHat 8.0, kernel 2.4.18-14 (default kernel) 

PERFORMANCE
------------------
VENUS-on-SCM
time dd if=/dev/zero of=/coda/server bs=1024 count=1024
real    0m0.142s
user    0m0.004s
sys     0m0.004s

VENUS-on-CLIENT
time dd if=/dev/zero of=/coda/server bs=1024 count=1024
real    0m18.121s
user    0m0.000s
sys     0m0.010s


*****************************
Figure 3 - Here is everything OK. quick write from venus on SCM and
client too. 

SCM
--------
COMP: eServer 305
OS: RedHat 8.0, kernel 2.4.18-14 (default kernel) 

CLIENT -VENUS
--------
COMP: eServer 305
OS: RedHat 8.0, kernel 2.4.18-14 (default kernel) 

PERFORMANCE
-------------------
VENUS-on-SCM
time dd if=/dev/zero of=/coda/server bs=1024 count=1024
real    0m0.114s
user    0m0.002s
sys     0m0.008s

VENUS-on-CLIENT
time dd if=/dev/zero of=/coda/server bs=1024 count=1024
real    0m1.023s
user    0m0.002s
sys     0m0.010s



******************


vice-setup
Welcome to the Coda Server Setup script!

You already have a file /etc/coda/server.conf!
Continueing will remove that file.
Do you want to continue? [yes/no] yes
Setting up config files for a coda server.
Do you want the file /etc/coda/server.conf created? [yes] yes
What is the root directory for your coda server(s)? [/vice]
Setting up /vice.
Directories under /vice are set up.

Is this the master server, aka the SCM machine? (y/n) y

Setting up tokens for authentication.
The following token must be identical on all servers.
Enter a random token for update authentication : aaa
The following token must be identical on all servers.
Enter a random token for auth2 authentication : bbbbbbbb
The following token must be identical on all servers.
Enter a random token for volutil authentication : cccccccc
tokens done!

Setting up the file list for update client
Filelist for update ready.
/etc/services already has new services registered! Good.
/etc/services ready for Coda
Now installing files specific to the SCM...

Setting up servers file.
Enter an id for the SCM server. (hostname sklad1)
The serverid is a unique number between 0 and 255.
You should avoid 0, 127, and 255.


serverid: 1
done!
Initializing the VSGDB to contain the SCM as E0000100
/vice/db/VSGDB set up

Setting up ROOTVOLUME file
Enter the name of the rootvolume (< 32 chars) : coda.root


Setting up users and groups for Coda

You need to give me a uid (not 0) and username (not root)
for a Coda System:Administrator member on this server,
(sort of a Coda super user)

Enter the uid of this user: 500
Enter the username of this user: admin
An initial administrative user admin (id 500)
with Coda password changeme now exists.

A server needs a small log disk partition, preferrably on a disk by
itself. It also needs a metadata partition of approx 4% of you
filespace.

For trial purposes you may give oridnary files instead of raw
partitions. Keep all size small if you do this.
Production servers will want partitions for speed.

-------------------------------------------------------
WARNING: you are going to play with your partitions now.
verify all answers you give.
-------------------------------------------------------

WARNING: these choices are not easy to change once you are up and
running.

Are you ready to set up RVM? [yes/no] yes

What is your log partition? /dev/sda5

The log size must be smaller than you log partition.  We
recommend not more than 30M log size, and 2M is a good choice.
What is your log size? (enter as e.g. '2M') 20M

What is your data partition (or file)? /dev/sda3

The data size must be approx 4% of you server file space.  We
have templates for servers of approx: 500M, 1G, 2.2G, 3.3G, 8G
(you can store less, but not more on such servers).
The corresponding data sizes are  22M, 44M, 90M, 130M, 315M.
Pick one of the defaults, otherwise I will bail out

What is the size of you data partition (or file)
[22M, 44M, 90M, 130M, 200M, 315M]: 200M

--------------------------------------------------------
WARNING: DATA and LOG partitions are about to be wiped.
--------------------------------------------------------

  --- log area: /dev/sda5, size 20M.
  --- data area: /dev/sda3, size 200M.

Proceed, and wipe out old data? [y/n] y


LOG file has been initialized!


Rdsinit will initialize data and log.
This takes a while.
rvm_initialize succeeded.
Going to initialize data file to zero, could take awhile.
done.
rds_zap_heap completed successfully.
rvm_terminate succeeded.

RVM setup is done!


Your server directories will hold the files (not directories).
You can currently only have one directory per disk partition.

Where shall we store your file data [/vicepa]?
Shall I set up a vicetab entry for /vicepa (y/n) y
Select the maximum number of files for the server.
[256K, 1M, 2M, 16M]:
2M

Server directory /vicepa is set up!

Congratulations: your configuration is ready...and now

createvol_rep coda.root E0000100 /vicepa


--------------------
VENUS SETUP

venus-setup sklad1 20000

On St, 2003-01-29 at 17:12, niraj tolia wrote:

> Vojtech,
> Are you sure the difference is not that the first setup was working in 
> write-disconnected mode and the second in write-connected? You can check the 
> status by doing a cfs lv </coda/volumename>
> 
> Niraj
> 
> 
> 
> 
> 
> 
> >From: Vojtech Moravek <vojtech.moravek_at_cz.tiscali.com>
> >To: codalist_at_coda.cs.cmu.edu
> >Subject: write speed
> >Date: 29 Jan 2003 14:19:18 +0100
> >
> >Hi All
> >thanks for previous help with  data consistent..everything looks good.
> >And CODA is exatly what I want.
> >
> >But I find new problem,  previous i tested coda on three IBM eServers
> >305 and everything work fine and quickly.
> >
> >Now i installed CODA on IBM eServer 345 with HW RAID and two CPUs. I do
> >exactly same as before, but after installed CODA server and Venus write
> >operations are very very slowly.
> >
> >Used RedHat 8.0 with original or recompiled vanila kernel .. situation
> >is same :( After two days with finding problems i don't know where is
> >problem..the logs are clear.and nothing looks bad :(
> >
> >
> >I know, this is question  for IBM developers, but somebody have solution
> >maybe.
> >
> >I can connect this computer to internet and give account.
> >
> >Best regard
> >Vojtech Moravek
> 
> 
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Received on 2003-01-30 09:45:34