Asustor NAS Replace Volume 1

[Tavis75]

Hi,

I recently purchased an Asustor NIMBUSTOR 4 AS5304T, with 3 16TB SATA drives and a single 64GB SSD drive, I have set it up as a single volume RAID-5 using the 3 16TB drives with the SSD as a read-cache drive. However, I have noticed that some of the apps running on the system will periodically access the drives, meaning they never hibernate, putting up the energy usage of the system by about 3-4 times.

I am thinking therefore that it might be better if I used the SSD as Volume 1 of the system and had the RAID-5 array as a second volume (I don't think I really need the SSD cache as the system will mainly be used for media streaming, so the regular drives should be plenty fast enough).

So firstly, does anyone know if this is likely to help with the drive access problem?

And secondly, can I do this by resetting the system and setting it up again with just the SSD installed as Volume 1, and then adding in the RAID drives to create a new Volume 2 with my data intact? Obviously realise I'd have to re-setup all the various apps etc. but as the system is pretty new that shouldn't be much work, but I'd prefer to not have to copy across the data again as it is about 20TB, so it takes days! Luckily I still have the original data, so I could just clear everything and start again, but I'd prefer to avoid that if I could.

ASUS support site says you can place existing drives into a new NAS and it should work, but think that is a case of putting them in and using them as the same volume, so not quite what I want.

 

[Tavis75]

Yes, I'm not using Plex, but something similar called Zappiti Server, however, I don't believe it should constantly scan for new media as you have to set that off manually, so I'm hoping that whatever the drive access is related to would be able to run on the SSD, rather than needing to access the main drives.

 

[Tavis75]

Well, seem to have got it to work. Did a full reset of the system with just the SSD in, then put the RAID disks back, did some messing about with a config file using SSH and it now seems to be correctly recognising the RAID array and all my files are showing up! The hard disks have also finally gone to sleep, though have not yet re-installed the server software for my media player, so will see what happens when I do that!

What's the issue with a 3 disc RAID 5 array BTW, just the amount of usable storage compared to the size of the drives, or is there something else I should be aware of?

 

[Tavis75]

Raid 5 in general is a bad idea - if one drive fails, the stress of rebuilding / possibility of an unrecoverable read error during rebuilding, will often cause the array to fail completely and lose data.

Raid 5 can still make sense - it's the most space efficient raid with at least some kind of resilience - it's ideal for storage of media and the like that is only an inconvenience if a failure does occur - it shouldn't be used for irreplaceable data (although irreplaceable data should be backed up in more than 1 place anyway)

Ah right, the drive is used for storing my media collection, with the original discs (CDs and DVDs) boxed up and stored, so not unrecoverable data (just annoying as it will take an absolute age). So RAID5 is probably suitable for my use case, obviously something more robust would be better but that would require more drives and a bigger NAS, so more cost.

 

[Tavis75]

Well, the change seems to have done the trick. With the media server software set up and working the drives are still able to go into hibernation and the power usage drops, so seems successful overall.