In a summary I went on testing how transfer speeds would variate between transferring to and between SSD/HDD and if there was noticeable difference between software RAID 1 setup and separate drives. All my testing went pretty much bogus from the beginning, as I got shocked by my transfer speed through the network becoming just a fraction of what it used to be earlier though the network...
From Dr. Serverstone's jungle diary:
"Mon 6 Jan 15:35:15 EET 2020:
Transfer to SSD (second test below) is basically just as fast as on HDD (first test below). Networking is the bottleneck now. There is a setup where the sending computer is connected to switch and then router, while the server is hooked directly to the router. This might be an issue.
Transfer package 15.9 GB. Transfer speed was maybe around 11 MB/s.
Test 1, time cp to HDD: 22:45.97 min
Test 2, time cp to SDD: 22:41.18 min
What the fart has happened with the speed though?!?"
The diary doesn't directly tell me whether that was a copy on RAID drive, but as far as I know the RAID was disabled at this point. At this point I had installed a new CISCO Ethernet Switch, and I started to suspect it actually caused some serious slowdown even while that should have not happened.
 |
| Is this the culprit for lost networking speed? |
More notes from Dr. Serverstone's jungle diary:
"Mon 6 Jan 16:10:37 EET 2020:
New test - both computers straight to router. Transfer speed to SSD up to around 56 MB/s with dropdowns to around 25 MB/s probably during file switch. Package size 8.2GB. Transfer to HDD seemed more or less similar, however, at least dropdowns seemed less deep.
SSD test: 3:59.37
HDD test: 2:57.62
Transfer speeds were now largely as expected regarding to networking. As a surprise though, HDD transfer this time was 25% less than the SSD transfer. This would suggest that the motherboard connection employs SATA 1 connection while the PCIe card with SATA adapters go with SATA 2. This also means that the SSD seems speedwise practically useless on this drive."
Of course there could have been some random variation as well, since there were no repeated testings done. The old computer's resources were considerably limited, so sometimes the computer just started hickuping with background processes that would be nothing for a modern computer. This was of course one important part of my testing too.
Server Jungle diary continues:
"New test - both computers connected straight to router. Transfer speed to SSD up to around 56 MB/s with dropdowns to around 25 MB/s probably during file switch. Package size 8.2GB. Transfer to HDD seemed more or less similar, however, at least dropdowns seemed less deep.
Transfer speeds were now largely as expected regarding to networking. As a surprise though, HDD transfer was 25% less than the SSD transfer. This would suggest that the motherboard connection employs SATA 1 connection while the PCIe card with SATA adapters go with SATA 2. This also means that the SSD seems speedwise practically useless on this drive."
So yea, something often overlooked with recommending SSDs as a boostup for an old computer: if it's a computer old enough to only use SATA 1, it's not really of use anymore... My wife's old laptop Lenovo Thinkpad T61 from 2007 (which she btw used no problem till the Autumn, and still occasionally uses - I bought her an used Thinkstation S30 desktop computer from 2013 as a replacement for sort of a late Christmas/wedding gift, so that we could play World of Tanks and some other games together more properly) was boosted with an SSD drive and there it worked fine and speeded up a lot - but only after BIOS upgrade, since the stock BIOS did not support SATA 2 even while the hardware itself supported it. Although it also must be remembered that an old HDD is often also a lot slower than a new HDD, and these HDDs were brand new Western Digital Red NAS drives.
Server diary continues:
"Mon 6 Jan 16:51:49 EET 2020:
Important general test result:
SSHFS process was constantly below 50% CPU now that there was no software RAID applied to. With the software RAID the CPU was regularly hitting at least over 80% values.
Test with HDD moved straight to HDD. There seemed to be a longish hiatus at the beginning of transfer, after which the transfer rate seemed to jump all the way to around 59 MB/s, before returning to similar transfer rates as before - but the minimum apart from file change drops seemed to be around 55 MB/s.
HDD: 3:27.71
Slower than with HDD in SATA adapter but faster than SDD on mobo. Weird results. Testing yet another part with bigger 15.9 GB package. Previous packages were those 8.2 GB.
HDD on mobo SATA, 15.9 GB package: 4:59.34
This transfer result is still faster than earlier tests for the same package on RAID and direct to SSD. A bit puzzling, might be certain degree of random variation included... For confirmation, maybe one more test with this specific setup is recommended.
Last test with this networking is a transfer to a solo HDD on PCIe SATA adapter. Transfer speed shows huge fluctuation now constantly from 14 to 57 MB/s or so with this 15 somethin GB package. In the end the transfer went on stable high rate again, so all this fluctuation might be due random factors with networking or computer processing.
HDD on SATA adapter, 15 GB package: 7:45.14
Overall I should've made multiple times the same test and take the average.
HDD on SATA adapter, 8 GB package: 2:42.61
Nevertheless, now the SATA adapter package on HDD won again with the smaller package - the fastest time of all in fact. I guess I'll simply plug in both drives to the adapter as they used to be, adds to clarity both inside and on operating system as well.
However, I should yet confirm that the speed is sufficient if both computers are going through the Ethernet switch. And that is where the disappointment comes up. With the CISCO switch the transfer speed just can't get past 12 MB/s or so. Not even while the both computers are in the same network.
HDD through switch, 8 GB package: 12:37.09
Switch instructions say to connect the switch by address 192.168.1.254, but that doesn't work unless if my computer is in the same subnet...which is not true. My computer is in 192.168.10.x, so how do I access that address? The switch should be suitable for up to a gigabit transfer rate (125 MB/s), but now it's only running apparently with 100 megabit speed. This should be configurable, but I can't access the web utility now...
Solution to access the subnet was by changing the LAN settings from router. Then I could access the switch and set it go back to the wanted subnet, after which I set the router settings back again. Unfortunately this flushed my old IP address settings as well down the drain, so some of my manually made scripts will now have incorrect IP addresses. Oh well, it's not so big thing I guess. Maybe some of the biggest things are about setting couple old LAN games working again by the correct IP such as Borderlands.
In addition obviously my connections with my server got quite messed up since I didn't shut down everything before changing settings..."
IP address calculations with all the subways and gateways can actually mess up my head quite nicely when the numbers start to roll around, but it was then found out that there was not so much to adjust with the switch settings manager. Or should I rather say, there was no need to change much.
Diary comes to its climatic plot twist:
"Mon 6 Jan 19:25:26 EET 2020:
Then I found out that Port Settings from the Switch allowed only 10FDX speed to my main computer. The unthinkable had happened: I had used an old Ethernet cable was which was of Category 5, not even 5E. CAT 5 is basically obsolete and it should not be able to reach higher than theoretical maximum of 100 Mbps speed. Now that I changed cables to CAT 5E the Switch shows port speed as 1000FDX, which is more appropriate.
 |
| Just. Single. Letter. Difference. One doesn't encounter CAT5 much nowadays. |
HDD 8GB with Switch and CAT 5E: 3:36.57
HDD 15GB on the same setup: 5:21.64
Then finally I plugged in my server directly to router again with my desktop client behind router & switch. This is because the switch and desktop are in another room with other computers, and the cablings would go awkwardly should I connect also the server to the switch. Transfer speeds seem all sufficiently decent ~50 MiB/s +/- something again also this way. Might in theory be marginally faster to have both computers running through the switch, but to be honest it doesn't matter that much anymore, and it might just as well be all random variation in every transfer anyway. In addition, at least the final test yielded in any case the fastest transfer results.
2:53.58
For the end I'll just yet reconnect both HDDs on my obsolete Fujitsu-Siemens server back to the SATA adapter card and close the case for now. Next stage would be setting up the server accessable for all local computers and users with corresponding folders and so on. This I'm not going to do today, since I already wasted one day of a well deserved extended weekend day."
Again the diary doesn't define which package was that fastest transfer; it would make sense for it to be the 8GB package, but if it really was the fastest transfer, there was above one faster transfer case with 8GB. I probably was just being sloppy with my markings, since like said my notes were largely a mess. In any case, I was really happy after substantial amount of frustration to realize it was the old cable that caused slow transfer, and I didn't feel like testing RAID etc. again anymore.
Speaking of which though, the tests yielded one more important general test result:
"SSDFS [service process for file transfer through SSH] was constantly below 50% CPU now that there was no software RAID applied to. With the software RAID the CPU was regularly hitting at least over 80% values."
This means that the software RAID application mdadm actually does take a fair deal more of processing power - too much from this cake. In all documents I read about mdadm it was stated that in theory a software RAID might take a bit more CPU resources than a hardware RAID, however that would not have any practical significance... Well surely so if the computer used is less than 5 years old and not 15 years old! Nevertheless, I find it actually awesome that such aged device is still actually usable for real, even while in practice one could likely get something more powerful with less watts consumption by dumpster diving today.
