Around 5 GB of copying progress monitoring shows: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util What could be the cause that the performance decrease effects are worse using network drives?ĭuring copying "iostat -dx 5" was used to monitor the disk performance. After a couple of GB the transfer rate has dropped far below 1 MB/s.Ĭopying was tried using drag and drop from Nautilus, command "cp", command rsync, FreeFileSync application, but all showed poor performance. Initially also a transfer rate of 70MB/s is realized, but the transfer rate drops must faster. First the network drive is mounted to my system and then copying is started. When I try to copy from my Synology NAS to my local disk (sdb8) the effects are even worse. What is causing that my system has bad responsiveness for a couple of minutes after the copying action?ģ) Copying from network drive increases the effects Also is see that disk sda is not busy anymore, but disk sdb is still operating at 100% busy. During the time that IOwait is decreasing, my system still suffers from bad responsiveness. Using iotop it looks like the process "jdb2/sdb4-8" is causing this disk write. I think that during that time data is still written to sdb at a rate around 1 or 2 MB/s. When copying has ended I notice that iowait is still high and gradually starts to reduce to normal values. Is this normal behaviour? How can the decrease in performance be avoided? I expect the iowait to be the cause of that. Not only the transfer rate drops but also my system becomes less responsive.
After that the transfer rate really starts to fluctuate and drops below 1MB/s.Īt the same time I see that iowait is increasing from initially 0% up to 62% at the end.ĭuring copying disk sd8 has a 'busy' percentage between 40% and 60%. At 30GB progress the transfer rate has dropped to 58 MB/s, at 46 GB to 36MB/s, at 52GB to 12 MB/s. I am monitoring the performance using glances, atop, iotop and iostat. When I try to copy more than 50 GB I notice that gradually the transfer rate decreases. In the example I copied a disk image file of 54GB from sda8 (325 GB partition) to sdb8 (1.6TB partition)ġ) Transfer rate decreases and iowait increases
Google drive transfer speed freefilesync how to#
My question is whether or not this behaviour is normal and to be expected in Linux systems?Ĭan anyone explain this to me and advise me how to avoid this performance decrease?īelow I will describe my observations. When I copy data (30GB) from one disk to another I notice several performance issues. I am using a Ubuntu 16.04.3 LTS system (4.10.0-40-generic) with two HDD's and several partitions on each disk.
0 kommentar(er)
