blondvillain

Look I'm not here to debate SMR. I'm tyring to get some insight into the workings of DrivePool. Please stop derailing the thread.

Ok so that makes sense when it comes to evacuating files into the pool from a drive designated as SSD. But let's take SSD Optimizer out of the equation. If you initiate multiple transfers to DrivePool simultaneously, why wouldn't it route each one to a different drive? This is supposing the SSD Optimizer balancer is NOT in use. Scenario: -SSD Optimizer balancer is NOT enabled. -You initiate a transfer from F:\, and independent locally installed drive in SERVER1 to a local pool P:\. It begins writing files to the drive in the pool with the most free space available, which as I understand is the default scheme. -You initiate a second transfer from SERVER2 across the LAN to SERVER1's pool P:\. It begins copying files to the drive with the most free space, which is the same drive the first transfer is currently writing to. In this scenario you now have two independent single-threaded copy operations happening, and contending for IO on the same drive, which in my experience is not ideal. Two simultaneous file transfers will usually take longer than two consecutive file transfers, not to mention the potential for added wear and tear as the write head has to jump around more to accommodate both writes. So why doesn't DrivePool route these two independent transfers to separate drives? This wouldn't be "multi-threaded" as I understand the concept. Consider this scenario where DrivePool isn't involved at all: suppose I have 4 separate hard drives (HDD1, HDD2, HDD3, HDD4). Using Windows File Explorer, if I copy a file from HDD1 to HDD2 and simultaneously copy a file from HDD3 to HDD4, both transfers progress at full speed and Windows tracks them in separate progress windows. In my opinion, this seems like something DrivePool should be able to manage, not to mention seems to be standard operating procedure for Drive Bender.

The fact that Drive Pool only writes to one drive in the pool at a time is slowing things down quite substantially. How is yours configured to allow balancing to multiple drives at the same time? This is what I'm trying to accomplish, but the various configurations I've tried have failed to accomplish this. Also, it is well established that Seagate Archive drives highly variable sustained write performance. They use Shingled Magnetic Recording (SMR) technology, as opposed to Perpendicular Recording (PMR), and variable writes is a characteristic of SMR by design, and the main reason why Seagate Archive drives are so much cheaper than PMR alternatives of the same capacity. A quick Google search for reviews will turn up a lot of evidence supporting this. For instance http://www.storagereview.com/seagate_archive_hdd_review_8tb. Here's a quote from said review. "Below is a screenshot showing disk activity during the SMR RAID rebuild on top, where we see sustained write performance all over the map, including single digit throughput for long periods. This is compared to the PMR rebuild shown on the bottom half of the image which is able to stay over 100MB/s for most of the duration." So I don't know what drives you're talking about, but I have the ones that have variable write performance. Returning to the topic at hand: could you please share your Drive Pool configuration settings that enable balancing to multiple drives simultaneously?

I'm in the midst of transferring a large volume of data from an 8-bay NAS into a new DrivePool setup and I'm trying to speed up the process a bit. I tried using the SSD plugin with a 500 GB SSD to enable greater bandwidth for multiple file copy operation simultaneously, but the balancer can't keep up with the workload and the SSD fills up faster than it can evacuate. The issue seems to be that while the balancer is evacuating files from the SSD, it only places them on one drive at a time, despite the fact that several of the drives in the pool are below the "full" threshold. Many of the drives in my pool are slow Seagate Archive drives that have poor write speeds, so if the balancer limits itself to writing to only one drive at a time, it'll never be able to keep up with large volumes of incoming data. How can I configure DrivePool to balance incoming transfers across multiple drives in the pool simultaneously so that it can better handle large volumes of incoming data, either with OR without an SSD landing zone? The Archive drives are able to sustain reads at the normal 100+ MB/s, but writes are extremely variable, dropping into the single digits at times. Therefore, my pool is presently unable to accomodate the full speed of even ONE single incoming transfer. If it could be configured to balance incoming transfers across multiple drives simultaneously, it would really speed up the process. I've also been evaluating Drive Bender, and while I prefer DrivePool's interface, Drive Bender appears able to send multiple incoming transfers to separate drives in the pool without issue, and without any special configuration required. Just FYI, I'm NOT doing any file duplication or redundancy.