Hi all,
We recently bought an R730+MD3420+Md1220. The MD3420 connects to R730 through an 12GB HBA. All disks in MD3420+MD1220 formed a large RAID10 virtual disk, running RedHat Enterprise Linux 7. Related firmware for RHEL7 are installed.
With simple dd test like following, we found that write performance to the virtual disk is much slower (~25%-30%) compared with another RAID10 on an existing R730 (also 10Krpm disks, internal ones). We've write cache with mirroring enabled on the virtual disk. I wonder if
dd if=/dev/zero of=/mnt/testfile ***=512 count=1000 oflag=direct
Anyway, read performance is good enough (verifiedwith dd and hdparm -T).
I wonder if this is 'expected' (local disks are always faster than external storage?) or if we've something missed. Would anyone please advise?
Sorry for the naive question.
Thanks a lot.
Best Regards,
/ST Wong