@Sunil
So could you recommand generally mount options to set? At the moment
i've set none.
So is it always a good idea (don't need atime) to set
data=writeback,noatime,nodiratime any other options?
Stefan
Did you set the mount option on both nodes or only on the node
on which you were doing
If your apps do not care about atime, then noatime is helpful.
data=writeback should performs better than data=ordered. But
there is a small chance that files having trailing nulls if a node were
to reboot after a journal commit but before a data flush. This is
documented in the manpages and the
Hello list.
Apologies in advance, this may be a bit long. Just trying to give
as much info as I can at the outset.
I have a two node setup that share a 500Gig SAS drive via ocfs2.
When I move either large files 300Megs+ or a large number of smaller files
onto or off of the volume, my terminal
Repeat the same test but with volumes mounted with data=writeback
mount option.
mount -o data=writeback /dev/sdX /path
On 05/24/2011 07:11 AM, Keith W wrote:
Hello list.
Apologies in advance, this may be a bit long. Just trying to give
as much info as I can at the outset.
I have a two node
No change in behavior.
My mount options
/dev/sdj1 /u03ocfs2 _netdev,noatime,data=writeback,nointr 0 0
+---+
+ Keith +
+---+
On Tue, 24 May 2011, Sunil Mushran wrote:
Repeat the same test but with
Writeback will help if the writes are on one node and the ls on another.
It is not clear if that is the case or not.
If both ops are on the same node, then it just could be the disk is slow.
The times shows almost all wall time. Very little sys and no user. top
will show io wait times.
On
Yes, I am finding that if I do the large file copy on node1 and
do an ls -l on node1 it is very fast as expected.
If I do the large file copy on node1 and do an ls -l on node2
ls -l is showing multi second times. 5+ seconds at least.
If I do a file listing on any other file it is fast regardless
Did you set the mount option on both nodes or only on the node
on which you were doing the ls?
Setting it on both nodes, or on the node that is doing the cp should
solve the perf issue. What's happening is that the ls on node2 is forcing
node1 to journal commit. With the ordered data journal
Yes, I have the mount options the same on both nodes.
Am I understanding you correctly in that, this is normal
behaviour because node2 is forcing the journal commit?
If so that is fine, I just need to know so I can stop
searching for options.
I REALLY appreciate your looking at this. Thank
