Disk write I/O

[rohb]

Hi

We are using Symmetrix disks. Since the last few days I have observed the I/O on the disks to go high and reaches around 80%. At this time, the processes are writing to approx 13000 files in around 3-5 mins.

I am not a SAN expert, and neigther do I have quite disk knowledge, so I was looking for some help on this.

Can somebody please help me with the beloe:
1. How can I reduce high I/O on the disk apart keeping the files to be written the same.
2. What all information can I collect from the disks(such as the kb written per second)
3. I already checked that powermt is configured on the machine. Is there any other tool we can make use of in such scenarios.
One of the SAN guys suggested that one more of the slices be added to the slice we were using or he can make sure that we get a disk which nobody else uses.

Some of my questions might appear a bit vague, and I will be very happy to clarify. Please do let me know if I can provide any more information.
Thanks

Cheers
Roh

 

[RMGBELGIUM]

if its a windows OS the symmetrix is branched to , you can use perfmon for monitoring kb/sec.For unix hosts, that would be iostat.
If a write takes a certain number of IO's, the only way to tune that , is tuning the application that is doing the IO.You have to ask yourself, is it necesary that the app does so many IO's ?( could be a case of bad programming )

rgds,

R.

 

[jjjon]

What version of Symmetrix do you have? And where are you seeing the 80% disk usage - from the host or on the Sym?


J