RAID 5 expansion causing problems?

[James Prendergast]

Since october we have done 2 expansions on a RAID 5 array consisting of 5 drives. The first time we expanded it took 1 month to complete. The priority was set to low. This time it is set to low again and going on two weeks. We have noticed problems with SQL and nightly backups during these expansion windows. Is this typical and is there anyway around it? I thought when the expansion and rebuild priorities were set to low the ACU only worked during periods of no normal I/O.

[James ~ Happy Dude]

Hello James,
Firmwares on the server could be old now, as compared to the last expansion. Is it ?? Many new firmware versions were released recently.

Secondly, whats the BBWC for the Controller ? This makes a good difference during expansion. The higher, the better.

Yup, Setting the priority to low means expansion during MINIMUM I/O operations.

:) Regards.

[KarloChacon]

hi

low all the time... you know that extend and rebuild priority can change to low - medium - high at any time so when the workload for the server is not high you set the expansion priority to medium or high.

also as far as I know the the process works all the time on during low or high I/O

--- have you try changing the priority to high or medium and check the impact for the server???

is your server working I/O all the time all the day?

what is the BBWC size and which controller?

regards