LinuxQuestions.org
Review your favorite Linux distribution.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices


Reply
  Search this Thread
Old 10-05-2015, 02:05 PM   #1
ssmatale
LQ Newbie
 
Registered: Aug 2007
Posts: 2

Rep: Reputation: 0
Smile delayed acks issue on rhel 6.6


Hello All,

Hope you are doing well!

1. What problem/issue/behavior are you having trouble with? What do you expect to see?

We have rhel 6.6 server and we we are seeing to much delay on server and we are unable to disable it on the server.

[root@Server~]# netstat -s|grep dela
249698 delayed acks sent
20 delayed acks further delayed because of locked socket
[root@Server~]#

Where are you experiencing the behavior? What environment?
We are experiencing while reading data, writing is fine but its too slow while reading the data on mounted EMC storage

Red Hat Enterprise Linux Server release 6.6 (Santiago)

We are testing reading and writing with dd command tool. Testing result as below

[root@Server ~]# dd of=/dev/null bs=1024k count=2000 if=/test1/testingfile_5g
2000+0 records in
2000+0 records out
2097152000 bytes (2.1 GB) copied, 212.389 s, 9.9 MB/s

[root@Server ~]# dd of=/dev/null bs=1024k count=2000 if=/test/testingfile_5g
2000+0 records in
2000+0 records out
2097152000 bytes (2.1 GB) copied, 61.1459 s, 34.3 MB/s
[root@Server ~]#

We have below EMC storage and their mount point where we performed the test.
/dev/mapper/mpathbp1 is /test
/dev/mapper/mpathcp1 is /test1

We have Contacted EMC support and they have asked us to disable TCP ack delay in rhel 6.6. We have found below details on rhel portal to disable tcp ack delay but it works only on rhel 7.2 or it comes with kernal-rt package which is for rhel5.
https://access.redhat.com/solutions/407743
https://access.redhat.com/solutions/1529183#

We don't have any application hosted on this server, we are going to use this server for Rack DB server. Currently we are testing storage performance before putting this in production.

Storage details : EMC VNX 5400 (Block only)
Block software Version: 05.33.006.5.102
----------
NIC details
07:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet (rev 10)

driver: bnx2x
version: 1.78.19-0
firmware-version: bc 7.12.83 phy 1.34
bus-info: 0000:07:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes
-------------
04:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet (rev 10)
[root@Server~]# ethtool -i eth0
driver: bnx2x
version: 1.78.19-0
firmware-version: bc 7.12.83 phy 1.34
bus-info: 0000:04:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes
[root@Server~]#


We don't have RHEL support with us hence looking for help.


Thanks
Sunil

Last edited by ssmatale; 10-07-2015 at 02:02 PM.
 
Old 10-06-2015, 01:15 PM   #2
smallpond
Senior Member
 
Registered: Feb 2011
Location: Massachusetts, USA
Distribution: CentOS 6 & 7
Posts: 2,969

Rep: Reputation: 794Reputation: 794Reputation: 794Reputation: 794Reputation: 794Reputation: 794Reputation: 794
For a production system running RedHat you should contact RedHat support.
 
1 members found this post helpful.
Old 10-06-2015, 02:25 PM   #3
TB0ne
LQ Guru
 
Registered: Jul 2003
Location: Birmingham, Alabama
Distribution: SuSE, RedHat, Slack,CentOS
Posts: 20,280

Rep: Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904
Quote:
Originally Posted by ssmatale View Post
Hello All,
Hope you are doing well!

1. What problem/issue/behavior are you having trouble with? What do you expect to see?
We have rhel 6.6 server and we we are seeing to much delay on server and we are unable to disable it on the server.

2. Where are you experiencing the behavior? What environment?
We are experiencing while reading data, writing is fine but its too slow while reading the data on mounted EMC storage Red Hat Enterprise Linux Server release 6.6 (Santiago)

3. When does the behavior occur? Frequently? Repeatedly? At certain times?
We have observed this behavior on very first time
All you've really told us is you're using RHEL 6.6. You say NOTHING about what you're reading/writing, what application(s)/service(s) you're talking about, how the EMC is connected, through what kind of HBA, what drivers, or ANYTHING that would help us help you.
Quote:
We need urgent help on this, any help highly appreciated on this.
Since you need 'urgent' help, I suggest you contact both EMC and Red Hat, since you're in a supported environment, and you are PAYING FOR support from them both, RIGHT??? Asking for/expecting 'urgent' help from volunteers is fairly rude.
 
Old 10-07-2015, 02:03 PM   #4
ssmatale
LQ Newbie
 
Registered: Aug 2007
Posts: 2

Original Poster
Rep: Reputation: 0
Post

Quote:
Originally Posted by TB0ne View Post
All you've really told us is you're using RHEL 6.6. You say NOTHING about what you're reading/writing, what application(s)/service(s) you're talking about, how the EMC is connected, through what kind of HBA, what drivers, or ANYTHING that would help us help you.

Since you need 'urgent' help, I suggest you contact both EMC and Red Hat, since you're in a supported environment, and you are PAYING FOR support from them both, RIGHT??? Asking for/expecting 'urgent' help from volunteers is fairly rude.
Thank you giving your valuable time for my issue.

I have edited my main post and given all required details.

Thank you very much
 
Old 10-07-2015, 03:13 PM   #5
TB0ne
LQ Guru
 
Registered: Jul 2003
Location: Birmingham, Alabama
Distribution: SuSE, RedHat, Slack,CentOS
Posts: 20,280

Rep: Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904Reputation: 4904
Quote:
Originally Posted by ssmatale View Post
Thank you giving your valuable time for my issue.
I have edited my main post and given all required details.
Editing your posts makes things harder for people, since it makes things less clear.
Quote:
We have Contacted EMC support and they have asked us to disable TCP ack delay in rhel 6.6. We have found below details on rhel portal to disable tcp ack delay but it works only on rhel 7.2 or it comes with kernal-rt package which is for rhel5.
https://access.redhat.com/solutions/407743
https://access.redhat.com/solutions/1529183#

We don't have any application hosted on this server, we are going to use this server for Rack DB server. Currently we are testing storage performance before putting this in production. We don't have RHEL support with us hence looking for help.
Then PAY FOR SUPPORT from RHEL, as you should. You'd then get the patch. And if this is a NEW server, stop where you are and THINK about what you're doing. You're putting a new system in, running an OLD version of the OS, and you're expecting good results....why?? Load the latest version of RHEL if you're PAYING for it, or load the free version of CentOS.

If you're using EMC storage, not paying for RHEL is just plain stupid. Your company OBVIOUSLY has the money to afford it. Pay for support, load the latest version, and use the support/patching you're entitled to. Otherwise, use the free CentOS software, and hope for the best.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
where is modified the congestion window after 3 dup ACKs are receibed? NANNOB1 Linux - Kernel 0 06-16-2011 02:08 PM
TCP ACKs in kernel code rrbarbosa Linux - Kernel 2 05-22-2009 07:13 AM
Cups Networking issue delayed printing. anonymousd Linux - Networking 3 01-22-2007 07:35 AM
Anyone managed to disable Acks? Titanas25 Linux - Wireless Networking 0 05-17-2006 07:31 AM
Duplicate ACKs arunachalam Linux - Networking 3 11-07-2005 11:28 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Software

All times are GMT -5. The time now is 03:47 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration