We just moved a user, who deals with a *lot* of data, to a new server, since his old NFS home directory was on a disk that had started showing problems.
Now, i/o is about six times slower, my manager reports.
After a fair bit of googling, I started looking at tc and ip, and found the following: from ip address show, first, on the old home directory server, eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast qlen 1000 then, on the new: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
I've tried tc qdisc add dev eth0 mq pfifo_fast and tc qdisc add dev eth0 pfifo_fast
and neither works. I've googled, and seen something about you can't set something with tc, because pfifo_fast is the hardwired default.
Anyone know how I can reset this, or is there a package I can reinstall that would do that?
mark
From: "m.roth@5-cent.us" m.roth@5-cent.us
I've tried tc qdisc add dev eth0 mq pfifo_fast and tc qdisc add dev eth0 pfifo_fast and neither works. I've googled, and seen something about you can't set something with tc, because pfifo_fast is the hardwired default.
Not an expert, but this seems to add 'mq' succesfully on my unused eth1: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 # tc qdisc add dev eth1 root handle 1: mq eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN qlen 1000
But it fails for 'pfifo_fast': # tc qdisc add dev eth1 root handle 1: pfifo_fast qdisc 'pfifo_fast' does not support option parsing
Also, maybe you need to delete before adding?
JD
John Doe wrote:
From: "m.roth@5-cent.us" m.roth@5-cent.us
I've tried tc qdisc add dev eth0 mq pfifo_fast and tc qdisc add dev eth0 pfifo_fast and neither works. I've googled, and seen something about you can't set something with tc, because pfifo_fast is the hardwired default.
Not an expert, but this seems to add 'mq' succesfully on my unused eth1: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 # tc qdisc add dev eth1 root handle 1: mq eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN qlen 1000
But it fails for 'pfifo_fast': # tc qdisc add dev eth1 root handle 1: pfifo_fast qdisc 'pfifo_fast' does not support option parsing
Also, maybe you need to delete before adding?
Yeah: after I tried to add it, and it gave me the "does not support options parsing", I began trying to del the mq, but I can't seem to find the Magical Syntax (tm) that let's me get rid of that.
mark
From: "m.roth@5-cent.us" m.roth@5-cent.us
Yeah: after I tried to add it, and it gave me the "does not support options parsing", I began trying to del the mq, but I can't seem to find the Magical Syntax (tm) that let's me get rid of that.
This worked for me... # tc qdisc del dev eth1 root handle 1
JD
On 03/01/2012 08:15 AM, m.roth@5-cent.us wrote:
We just moved a user, who deals with a *lot* of data, to a new server, since his old NFS home directory was on a disk that had started showing problems.
Now, i/o is about six times slower, my manager reports.
After a fair bit of googling, I started looking at tc and ip, and found the following: from ip address show, first, on the old home directory server, eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast qlen 1000 then, on the new: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
I've tried tc qdisc add dev eth0 mq pfifo_fast and tc qdisc add dev eth0 pfifo_fast
and neither works. I've googled, and seen something about you can't set something with tc, because pfifo_fast is the hardwired default.
Anyone know how I can reset this, or is there a package I can reinstall that would do that?
mark
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Are you sure your performance problems are network related? Have you measured performance of the filesystems on the two servers? You may have a data alignment problem with your disk partitions.
Nataraj
Nataraj wrote:
On 03/01/2012 08:15 AM, m.roth@5-cent.us wrote:
We just moved a user, who deals with a *lot* of data, to a new server, since his old NFS home directory was on a disk that had started showing problems.
Now, i/o is about six times slower, my manager reports.
After a fair bit of googling, I started looking at tc and ip, and found the following: from ip address show, first, on the old home directory server, eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast qlen 1000 then, on the new: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
<snip>
Are you sure your performance problems are network related? Have you measured performance of the filesystems on the two servers? You may have a data alignment problem with your disk partitions.
He did. It's not disk-related.
mark
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John Doe -
m.roth＠5-cent.us -
Nataraj