Im french so my english is probably not perfect...

 

Hi, im new to the forum and i just discovered UNRAID because i wanted an alternative to DROBO(Does the same thing as UNRAID but you have to pay 500$ for the box)

 

Anyways i am pleased with what UNRAID can do but i had a few suggestion that, i think, could improve UNRAID further::

 

1-UNRAID works great but its not fast comparing to other raid solution and im sure alot of people choose raid-5 over Unraid for this reason... in fact its often slower then 1 HD alone. Excluding the Parity HD it would be awesome if it was possible for UNRAID to span info of disk equaly between the disks like raid-0 would do. It would greatly speedup the read/write by alot. That way speed would be more comparable to raid-5 and we still retain the scalability.

 

3-Im sure write speed is limited by the speed at witch the parity disk can write so would it be a good thing to make some king of buffer to store in the ram and when idle use the time to write to parity. Sure it would help.

 

Sorry again if my english is not perfect.

 

Please let me know what you think of those ideas.

 

 

Your ideas are exactly why you should be using a standard raid setup like Raid 5... You've left out ALL of the advantages of unraid so why bother 

 

I dont anderstand what you mean.

 

You would still have the most important feature witch is scalability. being able to use HD of any size but with the advantage of added speed.

 

you would have 1 parity disk and lets say data disks of 1x250gb 2x320gb. That would mean that 750gb of the total data would be spanned like a raid-0 and would be 3x faster and the remaining extra 70gb would be at normal HD speed. Since its managed by software i think it could be done.

 

Also an other feature that would be good is being able to use the extra space on the parity disk... ex:

 

you have a 500gb parity disk and 2x100gb. you will loose 400gb of space. It would be good to be able to use that additionnal space...lets say in an additionnal volume to differienciate from the redundant volume. 400gb non-redundant + 200gb redundant is better then without

 

Let me know what you think and try to be objective.

jonz2k7,

unRAID is optimized for certain situations.  It will never be the perfect solution for every situation, and if it tries to be, it will surely become a less attractive solution for the implementations that it is optimized for.

 

Although striping data like RAID0 would make it faster, implementing it would directly negate one othe prime benefits of unRAID.  It would negate the benefit of the additonal saftey (i.e., safety beyond that provided by the parity disk) of fully intact disk-level filesystems which means that multiple drive failures does not equal total data loss as is the case in RAID0 and RAID5.

 

unRAID is optimized for write-once/read-many as is the need for serving digital media.  Even though there is much talk about parity speed on this forum and improving it would be welcome, for those of us using unRAID in the write-once/read-many scenario, there are other enhancements to unRAID that are more important.  Additionally, with the addition of the new cache-drive feature, perceived write speeds have been improved.

 

For my DVDs and MP3s, unRAID is perfect.  It is much better than other RAID implementations because of increased redundancy, ability to access data without spinning up all drives, and online capacity expansion.  However, I certainly wouldn't say my company should change its file server with constant reads and writes to unRAID.  

 

Although improved performance may be great, it's not worth it if it comes at the expense of the features that make unRAID ideal for its intended audience.

See below for info from the unRAID home page.  These features can't be supported with RAID striping.  That's why its called "unRAID"!

 

True Incremental Storage

Unlike other RAID systems, unRAID Server supports true incremental storage expansion. You can add capacity by adding more hard drives or by upgrading existing hard drives. This is a great way to make use of older, smaller hard drives you might have laying around.

 

For example, you might start out by installing one or two new high capacity hard drives along with some number of smaller hard drives you already own. Later, you might decide to replace one of the smaller drives, and unRAID Server will restore the data of the smaller drive onto the new drive, and then expand the file system to incorporate the full size of the new drive.

 

Better Fault Tolerance

Similar to other RAID systems, unRAID Server permits reconstruction of a single failed hard drive. However in the unlikely event of multiple hard drive failures, data loss would be isloated to only those hard drives which failed. In traditional RAID systems, multiple simultaneous hard drive failure results in complete data loss.

Please god no. The day unraid starts striping is the day i put it in the bin. It is THE feature i need and paid money for.

 

jonz2k7 what you are needing (as previously mentioned) is a proper RAID solution. There are many in existence to choose from.

if unRAID were to strip like RAID0 it would Be RAID4 or RAID5. The difference with unRAID is the individual filesystems sharing a parity drive for write once read many applications.

 

This is why many of us have chosen unRAID.

The only thing that "may" benefit from RAID0 is having the parity drive stripped across multiple spindles.

 

In the case of write speed throughput and your mention of a buffer, There is a feature called a Cache drives.

Whereby all writes occur there at the speed of a single drive and the data is moved over to the parity protected JBOD array overnight.

 

Another choice is to increase the amount of ram put into the system to help alleviate the parity update time.

 

 

There are a couple of FAQ entries, that may help in delineating the advantages and disadvantages of unRAID.

 

For another good discussion of the pros and cons of unRAID, see this thread.

The advantage of unraid is simple, you're not losing any space on each drive, you only lose one drive for parity and you can use different sizes and models, you can even mix scsi, ide and sata of you want.

Ok it's not that fast as an eSATA DAS disk, but it's a great replacement for DROBO.

 

DROBO supports also hotsizing but with all those extra's you lose space on your volume to protect your data. DROBO is expensive and to make it really useful u should buy DROBO-share too. Nice for professional use and for companies with a big wallet.

 

I have had RAID 5 en RAID 6 array's, the only thing they had was access time and a higher cost... with a special high-performance controller. I'm satisfied with the 20MB/s i have now. Fast enough and i can use all my old disks for backup.

 

I've tried open-filer and FREENAS.. but had several problems with the soft-raid.

 

I'm a happy unraid pro-user now.