Re: troubleshooting slow I/O performance.

By path I meant how the storage is connected to the server. Fibre channel, iSCSI, etc...

And I assume you mean that you have 30TB LUNs - I don't think there are 30TB physical disks. The actual number of physical spinning rusty things is the number that's important. E.g. how is your LUN made up?

And of course, it's also important to know how the disks are arranged when the LUN is built - RAID 1, RAID 5 (I hope not but that might explain the issues you're seeing) RAID 10, etc...

I'd say a friendly chat with the storage guy is probably in order :) It could be any number of things - but what's really key to get good performance out of bare metal drives is the number of drives you got.

On Tue, May 8, 2018 at 12:08 AM, Chris Stephens <cstephens16_at_gmail.com> wrote:

> ASM
> 6 30TB spinning drives
> type of path? we are not using asmlib or asm_fd (whatever its called).
>
>
> On Mon, May 7, 2018 at 11:54 AM Stefan Knecht <knecht.stefan_at_gmail.com>
> wrote:
>
>> Some details would help:
>>
>> - ASM or FS? Type of FS?
>> - LUNs? Numbers, sizes?
>> - metal? SSD? Type of path to the disks?
>>
>> Etc...
>>
>>
>> On Mon, 7 May 2018, 21:00 Chris Stephens, <cstephens16_at_gmail.com> wrote:
>>
>>> We have a new 5 node 12.2 RAC system that is not performing the way we
>>> want.
>>>
>>> The glaring issue is that "db file sequential read"'s are taking ~10ms.
>>> before i lob this over to the storage administrators, are there any
>>> possible areas in the clusterware/database configuration that I should
>>> investigate first? i have root access to all of the nodes. is there any
>>> information i can collect that would expedite the process of figuring out
>>> why we have such slow I/O times?
>>>
>>> slow i/o was discovered by running slob. if you don't know about that
>>> tool, you should. we all owe kevin a debt of gratitude. ;)
>>>
>>> if nothing else, i hope to learn a little more about storage than i
>>> currently know (which isn't much).
>>>
>>> thanks for any help.
>>>
>>> chris
>>>
>>>

-- 
//
zztat - The Next-Gen Oracle Performance Monitoring and Reaction Framework!
Visit us at zztat.net | _at_zztat_oracle | fb.me/zztat | zztat.net/blog/

--
http://www.freelists.org/webpage/oracle-l