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Re: high request queue

 
Deniz Cendere
Frequent Advisor

high request queue

Hi all,

We are trying to restore some number of datafiles to our system. Datafiles are approximately 100Gb. We started to restore, after a while it started to wait something, after 8 hours it didnt restore the datafile and passed to the other one. When I examined that 8 hours, I saw that no I/O s but very high request queues like 50 to 300 per disk. What do you think of the problem?

Also I have 4 luns and my luns sizes are 800 Gb. Their queue_depth is 8. What must be the queue_depth for these luns?

Thanks

Deniz
3 REPLIES 3
Steven E. Protter
Exalted Contributor

Re: high request queue


Shalom,

I've seen this when there is high activity on a system and a log of open filehandles, without the files actually needing to be there.

What is the LUN construction? Raid 5? This could be the result of a bad or near failure disk in the raid queue.

SEP
Steven E Protter
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skt_skt
Honored Contributor

Re: high request queue

does the syslog reports any type of I/O errors during that time frame..I would recommend an analysis from the SAN side for these four luns.
Deniz Cendere
Frequent Advisor

Re: high request queue

No I/O errors in the system logs, no disk failures. We were able to restore that file later.