Madoc Posted March 17, 2020 Share Posted March 17, 2020 (edited) Google seems unable to answer my specific questions, but it might be more that I dont know the terms to search for/what I'm reading. Drives: 1X 256g lighton SSD 1X 250g 840 EVO 1x 500g 860 EVO (brand new) As an additional wrinkle, this mboard only has 2 sata 3 ports the rest are 2. I will fix that with a new controller down the road, right now I have blown my budget for this project twice over. I tested the crap out of the 2 smaller drives they are good. I am running UD and UD+ (super useful especially during onboarding) So how I have it setup now, I added the 256g and the 250g to the cache. Which resulted in a 253g raid1....which seems wrong to me... 1) I wanted raid 1 for protection from a drive failure. Is it using the extra 6 gig on the 256 as 2x 3gig? How does it do that? However I was thinking. I have the min free space set to 4.7g so if that 'extra' 3 gig is at the END of the drive then it does not hurt me and actually helps me. Origionally I was planning on running the 500g alone and using it as a vm/docker/system store. Leaving the 250ish as the write cache and calling it a day. But other configs have occurred to me. 2) Would it be beneficial to raid 0 the 256 and 250, and then raid 1 that to the 500. I dont want to lose unraid monitoring of the drives so I was thinking the raid 0 would have to be software too. But this would way simplify management, I'd just set the shares to cache only and bobs your uncle. This also gives me raid 1 protection of the vm store. Since I'd be mixing sata 2/3 for now and old/new drives it'd be giving up a lot of of performance...but these are vms on ssds, its already going to be way quicker then my 15k rpm drives/SAS1 drives I'm coming from. This would also give me a much larger write cache when the active vm store is small. (I'm using a plugin that backs them up to the array nightly. My intension is just to delete them when I'm not using them and depend on the backups if I want them back.) Also debating on which drives to put on the sata3 ports, right now I have the 2 cache drives on it and the 500 on sata2 but the 500 is still running smart tests etc. Thoughts? Edited March 17, 2020 by Madoc Quote Link to comment
JorgeB Posted March 17, 2020 Share Posted March 17, 2020 3 minutes ago, Madoc said: So how I have it setup now, I added the 256g and the 250g to the cache. Which resulted in a 253g raid1....which seems wrong to me... https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=480420 4 minutes ago, Madoc said: 2) Would it be beneficial to raid 0 the 256 and 250, and then raid 1 that to the 500. You can't do that, all raid1 or all raid0, you can have a raid1 pool plus 500GB unassigned single device. Quote Link to comment
Madoc Posted March 17, 2020 Author Share Posted March 17, 2020 Thank you that thread not only answered #1 but also the additional questions that answer raised 2) There are ways to do it. I could use hardware to raid 0 the 2 drives. Then Unraid would see a 506 and a 500 and raid 1 them to a 500. Or I've seen people talking about using other tools (mdadm) to do linux software raid, so mdadm software the raid 0 and the rest is the same. Might not be able to do a raid of raids with btrfs but there are ways. What I'm wondering is would be benificial. Or am I just buying myself headaches. The raid1 pool and the 500 in UD is what I was thinking before and if it turns out my new idea is impractical or inadvisable thats the way I'll go. Quote Link to comment
testdasi Posted March 18, 2020 Share Posted March 18, 2020 (edited) Stick to RAID-1 pool + 500 UD. You can't do that kind of nested RAID (not that it's even recommended). Also RAID-0 is highly NOT recommended to new users due to their inability to appreciate the risks involved. Simplicity is an underrated value. Edited March 18, 2020 by testdasi Quote Link to comment
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