Hey guys,

 

I'm thinking about building an unRaid home server, but i'm going to use the same system for gaming aswell.

That brought me a question. Is it possible to choose another raid version over the standard unraid (Raid 4)? i would like to use Raid 5 because of it faster writing speeds.

 

Is this possible?

 

Thanks in advance!

unRAID doesn't use RAID like that.  More of a parity protected array.

You can use a dual SSD cache drive setup which should get you write speeds at network speeds while giving you data protection. 

unRAID is a NAS you store (via dedicated parity drive/s) protected files over the network.

 

Is is not a SAN product that you can access directly and treat as secondary storage for your Windows client.

 

I think that is what you mean?

 

If you want to install a Windows client for gaming (installed on an SSD) and unRAID for network storage (installed on a USB flash drive), then you can switch  between them using your BIOS boot options at startup.

unRAID is a NAS you store (via dedicated parity drive/s) protected files over the network.

 

Is is not a SAN product that you can access directly and treat as secondary storage for your Windows client.

 

I think that is what you mean?

 

If you want to install a Windows client for gaming (installed on an SSD) and unRAID for network storage (installed on a USB flash drive), then you can switch  between them using your BIOS boot options at startup.

Dual-boot is a bad idea unless you make absolutely sure no OS other than unRAID touches any unRAID disk.

Thanks for all the fast replies.

 

I'm thinking of the following setup:

 

4x wd red 2tb and 2x 256gb ssd.

 

If the parity drive's queue is full. will it use the cache drives to temp store the data and write it to the parity when the parity drive is available? in this way i won't get any write speed loss compared to raid 5 right?

 

And how much cache is recommended? because i will put my windows installation folder on the cache only (raid 1)

unRAID is a NAS you store (via dedicated parity drive/s) protected files over the network.

 

Is is not a SAN product that you can access directly and treat as secondary storage for your Windows client.

 

I think that is what you mean?

 

If you want to install a Windows client for gaming (installed on an SSD) and unRAID for network storage (installed on a USB flash drive), then you can switch  between them using your BIOS boot options at startup.

 

Well. thats not exactly what i mean, i don't mind accessing everyting via network drives, but i still want the speed advantage of an SSD (in share creation you can select cache only, that's what i'll use for my windows install share then). but i'm concerned about the speed of my storage drives. Some ppl say the unraid becomes slow when you write stuff because the parity drive can't hold up, but that's where de Cache drives are coming in right?

Yep, cache is used to give fast writes to Unraid, at a user defined time, the cache contents can be moved to the parity protected array. 

If the parity drive's queue is full. will it use the cache drives to temp store the data and write it to the parity when the parity drive is available?

That's not how parity works in unraid. The parity drive does not hold any files from any drive. It holds the answer to the equation formed by the list of all the bits of all the drives in that particular address. If any drive fails, unraid uses the parity drive plus all the other drives in a math operation to calculate what bits are missing from that address on the missing drive. As a result, ANY write to the parity protected drives results in a write to the parity drive in real time, as the write occurs, and if any single drive is missing, the contents are seamlessly presented as if the drive were still operational.

 

Unraid recently gained the ability to add a second parity drive, so any 2 drives can fail and unraid will still keep your data intact, but if more drives fail than you have parity drives, you will lose the data on all failed drives. The rest of the drives will still be fine.

If the parity drive's queue is full. will it use the cache drives to temp store the data and write it to the parity when the parity drive is available?

That's not how parity works in unraid. The parity drive does not hold any files from any drive. It holds the answer to the equation formed by the list of all the bits of all the drives in that particular address. If any drive fails, unraid uses the parity drive plus all the other drives in a math operation to calculate what bits are missing from that address on the missing drive. As a result, ANY write to the parity protected drives results in a write to the parity drive in real time, as the write occurs, and if any single drive is missing, the contents are seamlessly presented as if the drive were still operational.

 

Unraid recently gained the ability to add a second parity drive, so any 2 drives can fail and unraid will still keep your data intact, but if more drives fail than you have parity drives, you will lose the data on all failed drives. The rest of the drives will still be fine.

And that's also not how the cache drive works. Each user share can be configured to use cache or not. Only writes to user shares that are cached will use the cache drive. Writes to user shares that are not cached will not use the cache drive, and writes to an array disk will not use the cache drive.

If the parity drive's queue is full. will it use the cache drives to temp store the data and write it to the parity when the parity drive is available?

That's not how parity works in unraid. The parity drive does not hold any files from any drive. It holds the answer to the equation formed by the list of all the bits of all the drives in that particular address. If any drive fails, unraid uses the parity drive plus all the other drives in a math operation to calculate what bits are missing from that address on the missing drive. As a result, ANY write to the parity protected drives results in a write to the parity drive in real time, as the write occurs, and if any single drive is missing, the contents are seamlessly presented as if the drive were still operational.

 

Unraid recently gained the ability to add a second parity drive, so any 2 drives can fail and unraid will still keep your data intact, but if more drives fail than you have parity drives, you will lose the data on all failed drives. The rest of the drives will still be fine.

And that's also not how the cache drive works. Each user share can be configured to use cache or not. Only writes to user shares that are cached will use the cache drive. Writes to user shares that are not cached will not use the cache drive, and writes to an array disk will not use the cache drive.

 

But when you put it in auto it will use the cache if needed?

But when you put it in auto it will use the cache if needed?

No, all new file writes to a cache enabled share will be to the cache pool until it fills up. The mover will transfer them to the parity enabled array when it is scheduled, however often you set it.

 

Tom (Limetech) was talking about setting up an on demand system where the cache would be flushed to the array ASAP instead of waiting on the mover, but that hasn't been released yet.

But when you put it in auto it will use the cache if needed?

No, all new file writes to a cache enabled share will be to the cache pool until it fills up. The mover will transfer them to the parity enabled array when it is scheduled, however often you set it.

 

Tom (Limetech) was talking about setting up an on demand system where the cache would be flushed to the array ASAP instead of waiting on the mover, but that hasn't been released yet.

 

How does that work if i edit a large file like playing a game, "the whole game will be loaded into cache -> edits while playing the game are made on the cache -> everything moved to array at schedule".?

And that's also not how the cache drive works. Each user share can be configured to use cache or not. Only writes to user shares that are cached will use the cache drive. Writes to user shares that are not cached will not use the cache drive, and writes to an array disk will not use the cache drive.

 

But when you put it in auto it will use the cache if needed?

When you put what in auto? Only user shares can be cached. Each user share has a setting that controls whether or not it uses cache. Auto is not one of the choices for that setting.

How does that work if i edit a large file like playing a game, "the whole game will be loaded into cache -> edits while playing the game are made on the cache -> everything moved to array at schedule".?

If you edit a file that is already on the parity array the edits will be written directly to the parity array and not to cache.

And that's also not how the cache drive works. Each user share can be configured to use cache or not. Only writes to user shares that are cached will use the cache drive. Writes to user shares that are not cached will not use the cache drive, and writes to an array disk will not use the cache drive.

 

But when you put it in auto it will use the cache if needed?

When you put what in auto? Only user shares can be cached. Each user share has a setting that controls whether or not it uses cache. Auto is not one of the choices for that setting.

 

I misread that. my bad, there is an option cache only, that's where i'll store my Windows OS and game share

When you have a gaming machine on unRAID (VM) it will use either:

 

1. A vdisk (virtual disk) this can be stored on either your cache drive (normally ssd) so read/write speeds will be fast. You can also store a vdisk on a share on the array with parity. This wouldn't be as fast as on the cache. A vdisk used on a share which has cache enabled, would be moved to the array after the mover is first run. So that would then afterwards always be on the array and not cache.

 

2. You can use an unassigned disk outside of the array and store your vdisks on that. As it not part of the array will not be ever moved. Speed will be faster than on the array.

 

3. You can passthrough a whole disk outside of the array and install windows (or other os) directly to the disk without using a vdisk. This will give you the  fastest speed using this method, especially if this disk is an ssd.