search for: 712kb

Hello Phil, Wednesday, September 16, 2020, 7:40:24 PM, you wrote: PP> You can achieve this with a hybrid RAID1 by mixing SSDs and HDDs, and PP> marking the HDD members as --write-mostly, meaning most of the reads PP> will come from the faster SSDs retaining much of the speed advantage, PP> but you have the redundancy of both SSDs and HDDs in the array. PP> Read performance is

...rite speeds are presumably limited by the slowest device in the array. > > Sequential read QD32 > 187MB/s (2 x HDD RAID1) > 1725MB/s (1 x NVMe, 2 x HDD RAID1) > > Sequential read QD1 > 162MB/s (2 x HDD RAID1) > 1296MB/s (1 x NVMe, 2 x HDD RAID1) > > 4K random read > 712kB/s (2 x HDD RAID1) > 55.0MB/s (1 x NVMe, 2 x HDD RAID1) > > The read speeds are a completely different story, and the array essentially performs identically to the native speed of the SSD device once the slower HDDs are set to --write-mostly, meaning the reads are prioritized to the SSD dev...

...n the array as once any cache has been saturated, write speeds are presumably limited by the slowest device in the array. Sequential read QD32 187MB/s (2 x HDD RAID1) 1725MB/s (1 x NVMe, 2 x HDD RAID1) Sequential read QD1 162MB/s (2 x HDD RAID1) 1296MB/s (1 x NVMe, 2 x HDD RAID1) 4K random read 712kB/s (2 x HDD RAID1) 55.0MB/s (1 x NVMe, 2 x HDD RAID1) The read speeds are a completely different story, and the array essentially performs identically to the native speed of the SSD device once the slower HDDs are set to --write-mostly, meaning the reads are prioritized to the SSD device. The SS...

...hput from the log file shows it at about 73KB/s (from last nights log). This takes it to about 09:30 by which time I am in work and login. I can see the backup is still going, and when it comes to backup the final small partition (5MB in size), it does this in a few seconds and with a throughput of 712KB/s which is more like the throughput I get during the day! So why is the backup taking so long? I have checked for overnight cron jobs and disabled the cron.daily run (which kicks in at 4am). I ran top every 15mins (again via cron) overnight when the backup was not running, and could not really see...