Buying a RAID card without a BBU (Battery Backup Unit) with the intent of using it as such (not converting it to an HBA passthrough card), especially with RAID5 in mind, is not recommended. When the power goes out - you risk losing everything!
There are numerous pages if you google it such as this - http://www.raid-recovery-guide.com/raid5-write-hole.aspx
@Peter_W said:
Buying a RAID card without a BBU (Battery Backup Unit) with the intent of using it as such (not converting it to an HBA passthrough card), especially with RAID5 in mind, is not recommended. When the power goes out - you risk losing everything!There are numerous pages if you google it such as this - "Write hole" phenomenon in RAID5, RAID6, RAID1, and other arrays.
Shouldtn software raid be more stable as long as your main ssd dosent die? Backup is not my first priority since it will be way to expensive. Thats why raid 5 sounded like a good idea, with 5 drives. I would Get performance gain and it could have possibilites for rebuilding the raid if one disk dies.
The thing is, with RAID5 the toll it takes on your disks to rebuild that 1 failed disk will be so high (due to the size of the disks today) that it could potentially destroy a second disk too (since you’ll most likely have the same MTBF/AFR on them) in the process. And if the second disk goes out during the rebuild you lose everything since there is no backup. The performance gain you get with RAID5 has no impact on Plex at all if that is a concern.
Perhaps this could be an alternative for you if you still want to use Windows - https://forums.plex.tv/discussion/comment/1113655/#Comment_1113655
@dent^ said:
Shouldtn software raid be more stable as long as your main ssd dosent die? Backup is not my first priority since it will be way to expensive. Thats why raid 5 sounded like a good idea, with 5 drives. I would Get performance gain and it could have possibilites for rebuilding the raid if one disk dies.
Obviously it’s your money and you have to weigh the risks. I definitely wouldn’t do raid 5 (or raid 6 for that matter), without a backup. This is asking for catastrophic failure. If you have a 2nd disk die during the rebuild (which if you buy all the same disks at the same time, there is quite a possibility of this happening) the array is toast. Good luck in whatever you decide though.
@adamskoog said:
@dent^ said:
Shouldtn software raid be more stable as long as your main ssd dosent die? Backup is not my first priority since it will be way to expensive. Thats why raid 5 sounded like a good idea, with 5 drives. I would Get performance gain and it could have possibilites for rebuilding the raid if one disk dies.Obviously it’s your money and you have to weigh the risks. I definitely wouldn’t do raid 5 (or raid 6 for that matter), without a backup. This is asking for catastrophic failure. If you have a 2nd disk die during the rebuild (which if you buy all the same disks at the same time, there is quite a possibility of this happening) the array is toast. Good luck in whatever you decide though.
@Peter_W said:
The thing is, with RAID5 the toll it takes on your disks to rebuild that 1 failed disk will be so high (due to the size of the disks today) that it could potentially destroy a second disk too (since you’ll most likely have the same MTBF/AFR on them) in the process. And if the second disk goes out during the rebuild you lose everything since there is no backup. The performance gain you get with RAID5 has no impact on Plex at all if that is a concern.Perhaps this could be an alternative for you if you still want to use Windows - https://forums.plex.tv/discussion/comment/1113655/#Comment_1113655
Might aswell just have separete disks. If one dies i could just download everything again, but i kinda want a high read speed. Hopefully there will be coming more 4K blu ray rips and i would like to have the possebility to run 2 4K streams aswell as two 1080p streams. What is the recommended speed on the drives to keep that running? Thinking about western digital red 4tb nas disk’s.
I have been reading and googling for a while now, and i think i found a possible soloution which may work decent. Newest ubuntu desktop with plex media server aswell as a Lsi 9240i raid card. Have anyone testes this combination before? If so Feedback is very Nice.
LOL
RAID only doubles your storage cost with NO backup capability.
I do not understand why so many folks tout raid for PMS backup.
RAID only creates better uptime stats if a drive were to fail…
Come On guys we are not saving lives here nor do we need the uptime stats like Netflix needs.
Take the extra money you spend on RAID storage and use it for solid backup copies of your library.
Much better use of money, In My Opinion.
I maintain 3 copies of my library.
If the main PMS drives fail… I just move a backup drive in and then re-make the failed drive from backup.
Never had a requirement to be sure a movie continues to play if a drive fails while watching a movie!!! LOL
In this instance, Maybe it’s just s ByteHead thing… Dunno. (LOL RAID sounds soo sexy…)
However, I could be missing something that I do not understand…
Please explain.
Thanks
PS: This has been discussed before…
@jjrjr1 - Well, if you go for a RAID-setup that also protects against bitrot - such as BTRFS and ZFS - there’s the added protection against corruption that a simple backup won’t safe you from. You can read more about it in articles such as this -
"The worst thing is that backups won’t save you from bitrot. The next backup will cheerfully back up the corrupted data, replacing your last good backup with the bad one. Before long, you’ll have rotated through all of your backups (if you even have multiple backups), and the uncorrupted original is now gone for good.
Contrary to popular belief, conventional RAID won’t help with bitrot, either. “But my raid5 array has parity and can reconstruct the missing data!” you might say. That only works if a drive completely and cleanly fails. If the drive instead starts spewing corrupted data, the array may or may not notice the corruption (most arrays don’t check parity by default on every read). Even if it does notice… all the array knows is that something in the stripe is bad; it has no way of knowing which drive returned bad data—and therefore which one to rebuild from parity (or whether the parity block itself was corrupt).
What might save your data, however, is a “next-gen” filesystem."
LOL
I have been in this Biz for nearly 40 years and have never experienced what you call bitrot… (I think in this case actually called DataRot)
If a file fails I usually know about it… If a drive fails I definitely know about it… (I suspect a drive will fail before BitRot becomes an issue)
Also, I do not backup my entire library twice (I have 100tb of disk) Would be backing up continuously.
I just copy the files as added to the backup drives (2 other physical locations)]
Living in SoCal… I am more worried about fire and or earthquakes.
Therefore if my RAID setup were to be destroyed… My only copy of my library would be destroyed…
I have FAR to much time invested in my library to bear that risk…
I have no SLA with my friends sharing my PMS soooo. 100% uptime is not really required. (I do not charge for people using my PMS… No Guarantees)
RAID, to me, just doubles disk requirements with no meaningful protection for my library…
If we are worried about DataRot… (Really??) then I guess RAID IS the way to go…
And due to file checksums, a corrupted file usually will not copy without reporting an error.
taking backup off 11tb is just waste, its only movies and tv shows which i can download again, but i do want the extra read speed which i get from raid. I know that everything else than raid 1 isn’t really a “backup”.
Sure if your backup is download again… Great! all is good.
But my library consists of mostly Rips I have done…
Lots of time invested…
Would not EVEN want to start all over…
In Physical Time my Library represents nearly 3 years of work…
3700 HD movies
17000 TV shows
1000 Miscellaneous Videos
70000 Music Tracks
Several Books on Tape, Audible.com downloads (Which Require much special processing to remove DRM)
Do it all again??. Well Just Kill me first. LOL
Extra Read Speed… Give me a break… First time I ever heard THAT as a reason to go RAID… LOL
Is it Really worth the money for any negligible increase in read speed since the bottleneck is usually not the access speed of your HDDs…???
Let’s get real… RAID is just for Techno Geeks in this environment. Does not bring much to the table.
I know and have developed production systems with REAL SLA requirements and redundancy that do require RAID. But in those environments, the entire RAID array would be backed up to different media and stored in a different location. That is what Disaster Recovery and Backup Processes are all about
In this environment, no matter how hard I try, I cannot see justifying RAID for use on a PMS.
Sorry if that bothers anybody… Just My Humble Opinion.
Look at this HDR demo: You need a decent read speed to play if without any hiccups, also you never know what the future of 4k HDR blu ray will bring, what will be the overall bit rate? lets say i want to direct play at least one 4k HDR blu ray movie, and have 2 streams transcoding going on as well. My 8tb drive would kill it self and start making hiccups.
Resolution : 3840x2160
File size : 762 Mo
Duration : 01min 35sec
Format : TS
Codec : HEVC
Overall bit rate : 66.9 Mb/s
Bit depth : 10 bits
Frame rate : 59.940 fps
66.9 MBPS!!
That’s totally ridiculous anyway…
But what ever floats your boat…
LOL
Hell, The maximum allowable bitrate for BluRay DVDs is 54Mbps…
Althought that bitrate is almost NEVER seen.
Usually around 30Mbps at the most.
@jjrjr1 said:
66.9 MBPS!!That’s totally ridiculous anyway…
But what ever floats your boat…
LOL
All of the HDR demos which are out so far are on like 60mbit average, its pretty much i know, but i also have a 4k HDR TV. So i want to be future proof so when the 4k HDR blu rays gets ripped, i would like to play them and have a couple of streams at the same time. I also have a seagate 8TB disk now, which is slow as f… Regret buying that disk so much, but one experience richer.
I have 2 UHDs and 2 Roku 4s
All my 4K media direct plays to them from Plex.
My average bitrate for 4K media is around 15-20Mbps.
The 4K rendering is PERFECT. The only thing I can think of that could improve the rendering will be 10bit data.
I can stream 4-6 1080p transcodes and 2 4K streams concurrently with no problem on a non-raid setup…
If you can see the difference between 20mbps and 69.9mbps… you have better eyes than I do… LOL (Or a Much better TV)
All I am saying is Cost vs. Benefit, I do not recommend RAID as the way to go…
Take a look at this screenshot of my 8tb disk, the reading speed sucks
I see That!
@jjrjr1 said:
I see That!
Do you still dont think that my HDD are a bottleneck? This is why i want to switch all of them out for some wd digital red 4tb and do a raid5
The OP was HTPC Raid possibilities.
I use mostly all WD Drives. I have a mix of 2, 4, 8 TB drives. Disk is NEVER my bottleneck. (BTW my 8s are Seagate)
Also a factor is my library is spread across 8 HDDs so the load is sort of balanced across them depending on titles played.
(LOL My disk farm is ridiculous… I have 28 drives online… 8 of them are 4tb portables that hold my complete library for offsite storage and travel use.)
So I think you will be happy with the WDs
I just do not recommend spending the money for a RAID array as that doubles your disk requirement for no real benefit…
Buy a second drive and make a backup to that one…
Just my recommendation.
Although several folks disagree with me LOL
@jjrjr1 said:
LOL
I have been in this Biz for nearly 40 years and have never experienced what you call bitrot… (I think in this case actually called DataRot)
I’ve had multiple cases of it over the years, where the problem only became apparent after disk failure and the array couldn’t be rebuilt. I’ve also had issues where data stored in a single disk has become corrupted and so lost. In the grand scheme of things, these have been very rare cases though.
However, I will agree that RAID is not backup - RAID (and similar technologies) only provide protection from disk failure. ZFS, BTRFS and the like also provide protection from on disk corruption.
Personally, from an availability perspective, I’m in favour of RAID type setups. That way when a disk fails, I’m the only person who notices and nobody complains at me that they can’t watch their film 
