I'm trying to fix up a couple of old Lenovo x3650 M5 servers for storage servers (primarily for video). The hardware RAID (ServeRAID M5210 with 4GB cache and BBU) seems to do a great job of obtaining high sequential read/write performance to a RAID5 with 5 drives, but I've obtained better random read/write performance (significantly so) if I remove the cache, put the system in JBOD mode and use ZFS with a 256GB L2ARC NVMe. Conversely, sequential performance seems to drop by about half in such a configuration compared to just using the hardware RAID.
I have a table attached with my testing results. I had an outlier ZFS test that almost defies explanation and another where it drifted down to something closer to realistic speed. For the hardware RAID configurations, I've used XFS as the file system. For the table entry that mentions dm-writecache, I switched the M5210 to "write through" so that I still had read cache, but hoped not to double cache writes.
So, I'm trying to figure out how to get the best "compromise." I wondered: I can see on eBay there are a number of the appropriate HBA adapters (N2215) for sale. Would I benefit from taking out the M5210 and putting in one of those N2215's? Or should the M5210 pretty much be the same performance wise as long as I'm using JBOD?
Is there some other detail I might be missing to better configure the ServeRAID M5210?
I have a table attached with my testing results. I had an outlier ZFS test that almost defies explanation and another where it drifted down to something closer to realistic speed. For the hardware RAID configurations, I've used XFS as the file system. For the table entry that mentions dm-writecache, I switched the M5210 to "write through" so that I still had read cache, but hoped not to double cache writes.
So, I'm trying to figure out how to get the best "compromise." I wondered: I can see on eBay there are a number of the appropriate HBA adapters (N2215) for sale. Would I benefit from taking out the M5210 and putting in one of those N2215's? Or should the M5210 pretty much be the same performance wise as long as I'm using JBOD?
Is there some other detail I might be missing to better configure the ServeRAID M5210?
