JigglyJoe

well, i analyzed one of the "new" WD RED 4 TB with my PC and an advanced SMART test showed "Too many bad sectors", at about 91% of disk space. it was the same percentage the NAS reshape crashed. and i think that's why the rebuilding process went on forever... i just used a bad drive for reshaping without running an advanced test before... (and it was a used one from ebay 😅) so guys, please check all your drives before adding them to the volume 🙄 even changing the faulty disk with a completely new one did not help and the volume still was crashed. synology is really really sensitive... thank god we could restore everything with a live ubuntu stick. @Balrog every single one of my wd red drives are the same model so in this case it was not the problem.

Hey Guys, finally i've overcome myself to write my problem down. Hope you guys can help me. i have the DS918+ modell with DSM version 6.2-23739. I am using 8x4TB WD Reds plugged in the mainboard and 2x4TB WD Reds + 2 SSDs on a HBA controller. I use 8 WD Reds as a SHR with 1-disk worth of redundancy. Also i used the SSD Cache with 2 128GB SSDs. Now to my problem... I wanted to upgrade my SHR from 8x4TB to 10x4TB. since its not the first time adding new disks to the SHR i thougt its a good idea to add the 2 disks simultaneously (maybe this was the first step of my error series) first it seemed everything right but the reshape was extremely slow (cat /proc/mdstat said it would take 140 days to complete), after a few researches i changed the stripe cache size to the maximum of 16384. it worked instantly and cat /proc/mdstat said it would take less then a week. at about 40% the NAS suddenly was not reachable over IP or network, putty also didnt worked. after one day it was still not reachable so i restarted the NAS completely (yes i cut power and restarted). after rebooting the reshape progress went on from ca. 35% and i just changed the stripe cache size again so it would be faster. Also during the reshaping i used the NAS normaly, opened a few files and copy/paste stuff, but performance was very slow, in the end files copied with just 1MB/sec. So maybe a week later it was at about 95% and the next day i looked into the DSM it said my Volume crashed.. The Log said that both 2 new drives had an error close before finishing the reshape (dont know which error and i dont have screenshots). SMART tests of both 2 new 4TB drives are okay. the Volume was still reachable through network but most of the files where corrupt and not readable. the Repair function of the volume didnt worked. after clicking on repair nothing happened. so i restarted the NAS and since 16 days its still rebooting and i dont know what to do. htop says that the volume is reading at 160M/sec since 16 days! what is it reading?? i hope you guys can help me fixing this and help to restore my volume! Thanks for helping putty screenhot here: (jbd2/md0-8, /usr/bin/syslog, /synologrotated are writing every once in while a few bytes) .

Hi Guys! since i'm the starter of this topic i wanted to tell you what i've done i learned that my previously used sata controllers mentioned above didnt worked and that i have to use HBA controller from a known brand. so i searched one and finally bought a 8port "HP H220 IT Mode LSI 9205-8I PCI-e 3.0HBA" controller from HP. the one i bought from ebay was this one: https://www.ebay.com/c/22028264506 it came with all the needed cables. i just built it in, plugged my drives in it and all my drives where recognized on my mainboard i'm using all 8 ports with 8 drives. on the controller i tested it with all 8 slots and they are all working, now i can use 16 drives simultaneously 😮

thanks for the answers! i will look for some HBAs

Hey Guys , i've installed two 6port raid controllers in my XPEnology NAS but unfortunately it does'nt recognize any drive i plug in. i have the DS918+ modell with DSM version 6.2-23739 i'm using a Asrock Z87 Extreme4 Z87 Mainboard - https://www.asrock.com/mb/Intel/Z87 Extreme4/index.de.asp with two of MZHOU PCIe SATA Card with 6 Ports and with the Marvell 88SE9215 Chip - https://www.amazon.co.uk/MZHOU-Controller-Expansion-Marvell-88SE9215/dp/B07RMHH43W i stumbled across a few people in this forum who are using the Marvell 88SE9215 Chip. has it to do something with die 6port instead of beeing a 4 port card? is it possible to run the system with two 6port sata controllers with the Marvell 88SE9215 Chip? i also have a 2 port controller with an unknown chipset but this controller is working fine, just rebooting the system and die drives are recognized! but i need more than 2 ports Thanks for helping