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We are using Dell Power Edge R510 server as a central storage in Linux network. I have configured RAID6 on 10 near-line SAS hard disks. Using NFS i have exported one directory and mounted it on other machines.
Recently we are facing one problem, when anyone read/write big file (2-3GB)from NFS drive,others feel very slow access to that drive. Sometime we can't open simple text file till complete read/write process.
I have remounted NFS drive but still problem as it is.
Can anyone help me to solve this problem.
Last edited by umesh.pawar; 02-26-2015 at 01:16 AM.
Hi Everyone,
We are using Dell Power Edge R510 server as a central storage in Linux network. I have configured RAID6 on 10 near-line SAS hard disks. Using NFS i have exported one directory and mounted it on other machines.
Recently we are facing one problem, when anyone read/write big file (2-3GB)from NFS drive,others feel very slow access to that drive. Sometime we can't open simple text file till complete read/write process. I have remounted NFS drive but still problem as it is.
I will go though link which you sent in your previos quote.
Please find the details of NFS
NFS version:
nfs-utils-1.0.9-44.el5
system-config-nfs-1.3.23-1.el5
nfs4-acl-tools-0.3.3-1.el5
nfs-utils-lib-1.0.8-7.6.el5
Network structure:
It is NIS/NFS network.We have added central storage (NFS) for easy to access our projects files from any machines where nfs drive mounted. We have 15 compute nodes and each node have 12 cores processors.our 30 users running his simulation on that compute nodes and stored data on nfs.We have connected all compute nodes and nfs through layer 3 giga bit switch
Operating system of server where nfs configured: RHEL 5.5 64 bit
Thanks for taking interest in this issue.
I will go though link which you sent in your previos quote.
Please find the details of NFS
NFS version:
nfs-utils-1.0.9-44.el5
system-config-nfs-1.3.23-1.el5
nfs4-acl-tools-0.3.3-1.el5
nfs-utils-lib-1.0.8-7.6.el5
Network structure:
It is NIS/NFS network.We have added central storage (NFS) for easy to access our projects files from any machines where nfs drive mounted. We have 15 compute nodes and each node have 12 cores processors.our 30 users running his simulation on that compute nodes and stored data on nfs.We have connected all compute nodes and nfs through layer 3 giga bit switch
Operating system of server where nfs configured: RHEL 5.5 64 bit
First off...RHEL 5.5 is VERY OLD, and it's a commercial, PAY FOR distro. Have you contacted Red Hat about this?? The latest version is 7.x, and contains many improvements over what you have now. And is your system patched and current to RHEL's repositories? Are you PAYING FOR RHEL???
And you haven't mentioned what the users workstations are running, which makes a difference too. Going through basic NFS performance tuning should be done first, though.
We have not renewed subscription of RHEL, hence we can't take a support from red hat team.
All are branded workstations of HP & Dell.
Model numbers are:
HP Proliant DL 160
Dell PowerEdge R610
but please let me know is it os problem?
I have checked network performance on web console of manageable switch ,it shows normal network load.
I have checked disks iops using "dstate" utility which comes with operating system,I observed that when we read/write above 2-3 GB file on nfs, cpu "wait" time goes up.
We have not renewed subscription of RHEL, hence we can't take a support from red hat team.
Then stop where you are and RENEW IT. There is no point in spending such a large amount of money on hardware and software (as you have described), to not be supported. And AGAIN, I will point out that RHEL 5.5 is OLD, and may only be receiving security updates (NOT patches/software updates) at this point, and you'll only get THOSE if you pay. Load CentOS if you don't plan on paying for RHEL.
Quote:
All are branded workstations of HP & Dell.
Model numbers are:
HP Proliant DL 160
Dell PowerEdge R610
but please let me know is it os problem?
Again, no idea, since you haven't said anything about how NFS is configured, or if you tried ANY of the tips in the NFS tuning guides. And again, you still haven't said WHAT OPERATING SYSTEM THE CLIENTS ARE RUNNING. The models and hardware make no difference.
Quote:
I have checked network performance on web console of manageable switch ,it shows normal network load. I have checked disks iops using "dstate" utility which comes with operating system,I observed that when we read/write above 2-3 GB file on nfs, cpu "wait" time goes up.
Disk type: near line SAS with 7200rpm
And AGAIN, have you read through the performance guides you were given before???? There are MANY things to tune and monitor for NFS in those guides...did you bother to try ANY of them yet????
We are using Dell Power Edge R510 server as a central storage in Linux network. I have configured RAID6 on 10 near-line SAS hard disks. Using NFS i have exported one directory and mounted it on other machines.
Recently we are facing one problem, when anyone read/write big file (2-3GB)from NFS drive,others feel very slow access to that drive. Sometime we can't open simple text file till complete read/write process.
7.5. When I transfer really big files, NFS takes over all the CPU cycles on the server and it screeches to a halt.
This is a problem with the fsync() function in 2.2 kernels that causes all sync-to-disk requests to be cumulative, resulting in a write time that is quadratic in the file size. If you can, upgrading to a 2.4 kernel should solve the problem. Also, exporting with the no_wdelay option forces the program to use o_sync() instead, which may prove faster.
Actually, the quadratic nature of the time taken illustrates almost exactly my performance stats between a modern Debian kernel when writing to a cheapo backup device, using rsync over nfs.
No measurements, but it takes roughly 100 times as long to transfer a 10GB file as a 1GB file.
I blame my cheapo backup device (an ebay purchase).
Actually updated kernel version is available on that server where we created NFS drive: Kernel version: 2.6.18-194.el5xen
Ok...and you STILL have not answered any questions about the clients, or acknowledged the NFS tuning instructions. Unless you actually TRY something, performance isn't going to increase. You have said nothing about what operating system the clients are running, what NFS client they're running, or said if you did ANYTHING to the NFS server, after reading the NFS performance tuning guides.
Read the guides, and follow them. If you're still having problems, then you need to come back and PROVIDE DETAILS and ANSWER QUESTIONS, or there is nothing anyone, anywhere can do to help you.
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