March 15, 20242 yr Hi there! From what i understand, the unraid mover can move data from the primary storage (SSD cache) to the secondary storage (HDD array) and in reverse. Is it possible to keep predefined files/folders/shares on the cache as well as the array? My goal is to have the data on the SSD cache for reads and writes so that i don't have to spin up any disks when they happen. At some scheduled point all changes made to the data on the cache will be synced to the array in one whole swoop. Ideally, this functionality should exists parallel to regular mover/cache functionality (write cache for array that gets moved off the cache regularly, living space for vms and its data).
March 15, 20242 yr Community Expert No, as far as Unraid is concerned a file should only ever exist at one location.
March 15, 20242 yr Author Ok, next option i guess would be to have the cached shares on a seperate SSD only array and manually sync changes made there to an HDD array share/folder. Just to be clear on the terminology, if i have 3x HDDs and 3x SSDs that should be in a 'group' each, would that two arrays with three devices each or an array with two pools containing three devices each?
March 15, 20242 yr Currently the Unraid "array" is the classic individually formatted data drives with one or two parity drives. Files are not striped across drives, so each drive has its own free space. Pools are single or groups of disks that can utilize BTRFS or ZFS RAID levels. You can have multiple pools, but are required to have 1 and only 1 "array". In a future Unraid release the classic "array" will become just another pool type. Until then, you must have at least a single drive occupying disk1 in the classic array. Also, the built in mover currently only moves files between the array and a designated pool, no pool to pool moves with the built in mover. All root folders and their contents on the array and all pools are combined into the "user shares".
March 15, 20242 yr Author Quote Pools are single or groups of disks that can utilize BTRFS or ZFS RAID levels. Can as in optional? So i could have two pools (with the aforementioned 3x HDD and 3x SSD) each utilizing the classic individual unraid strategy? That would probably work for what I need. I could just set up a docker or cron job that syncs from the SSD pool to the HDD pool and for the 'classic' pool uses i'd have a third cache pool.
March 15, 20242 yr 21 minutes ago, Zimeic said: Can as in optional? I'm unclear what you are asking. If a pool is a single disk it can be formatted XFS, multi drive pools can use either BTRFS or ZFS. 22 minutes ago, Zimeic said: So i could have two pools (with the aforementioned 3x HDD and 3x SSD) each utilizing the classic individual unraid strategy? 1 hour ago, JonathanM said: You can have multiple pools, but are required to have 1 and only 1 "array".
March 15, 20242 yr Author Quote I'm unclear what you are asking. If a pool is a single disk it can be formatted XFS, multi drive pools can use either BTRFS or ZFS. I was asking if i'm forced to to run a multi drive pool in a raid of some sort like ZFS instead of XFS. I think I found an answer to my question after more research though: Up until now i was under the impression i have to group drives in some sort of group/pool/array/whatever before pointing a share to that group to utilize all drives included in that group. But as it turns out i can specify individual drives to use per share, so i'll just chuck all HDDs/SSDs into the array and create the 'groups' that way.
March 15, 20242 yr Drives in the classic Unraid array can't be trimmed, so SSD's may see performance loss over time. If you assign a parity drive, writes to the array are speed limited by the parity drive.
March 15, 20242 yr Author Allright, i think i figured out how to implement my wonky setup 😉 Quote Drives in the classic Unraid array can't be trimmed Just out of curiousity, i saw a trim section in the scheduler options, is that something different?
March 15, 20242 yr Community Expert Use the array as unraid intends but you can have as many “cache pools” as you want. Cache pools can be just about any configuration you want them to be in. Just Disks, RAID0, RAID1, RAIDZ, ZFS MIRROR, etc each cache pool can be its own setup too. Pool1 can be 4 SSDs that aren’t in any kind of RAID. Pool2 can be a RAID1 pool. Edited March 15, 20242 yr by MowMdown
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.