Some questions about Flexraid

[sNaKeBiTe]

Hey guys,

I'm in need of more storage :D
First I wanted to do a Raid 5 with a cheap 150$ 4-Port SAS Raid Controller, but then I saw some of you recommend Flexraid and it seems a lot better suited for my usage scenario. (Mostly big static media files)
Here is what I have:
2x Samsung Spinpoint F1 1000GB, (HD103UJ)
2x Western Digital Caviar Green 2000GB, (WD20EARS)

And these I'd buy:
2x Western Digital Red 3000GB (WD30EFRX) or Seagate Desktop HDD.15 4000GB (ST4000DM000)

I still have some questions about Flexraid though and I thought you might be able to answer them:

1.) Snapshot-mode is probably the best alternative for me, right?
2.) What would you recommend how often I Update / Quick Validate / Validate / Verify? How long does it take?
3.) Is it possible to automatically send drives to sleep when they are not in use?
4.) How does Flexraid distribute new data on the drives? Does it fill up drives, or does it try to keep all drives equally full?
5.) Is the read/write performance only dependent on the drive it get's written/read from?
6.) If one of the 3TB is PPU and both of the 1TB drives fail, can I rebuild them? (Since I have 3TB parity and only 2TB failed)

 

Thanks!
 

 

[looney]

Hey guys,

I'm in need of more storage :D

First I wanted to do a Raid 5 with a cheap 150$ 4-Port SAS Raid Controller, but then I saw some of you recommend Flexraid and it seems a lot better suited for my usage scenario. (Mostly big static media files)

Here is what I have:

2x Samsung Spinpoint F1 1000GB, (HD103UJ)

2x Western Digital Caviar Green 2000GB, (WD20EARS)

And these I'd buy:

2x Western Digital Red 3000GB (WD30EFRX) or Seagate Desktop HDD.15 4000GB (ST4000DM000)

I still have some questions about Flexraid though and I thought you might be able to answer them:

1.) Snapshot-mode is probably the best alternative for me, right?

2.) What would you recommend how often I Update / Quick Validate / Validate / Verify? How long does it take?

3.) Is it possible to automatically send drives to sleep when they are not in use?

4.) How does Flexraid distribute new data on the drives? Does it fill up drives, or does it try to keep all drives equally full?

5.) Is the read/write performance only dependent on the drive it get's written/read from?

6.) If one of the 3TB is PPU and both of the 1TB drives fail, can I rebuild them? (Since I have 3TB parity and only 2TB failed)

 

Thanks!

 

1. yes snapshot is very well suited for static media files.
2. mine quick validates and updates every 24 hours. but once every few days would also be fine in my case, update time depends on the amount of files you added since the last update, verify depends on the total data on the array/pool
3. !?! i think !?! spin down is handles by the OS, FlexRAID will ask the OS to spin up drives that need to be accessed. but im not sure on this part, never really looked into it. but I will.
4. Depends on the merge setting:

   auto space prio will fill the drives as evenly as possible.

5. Yes
6. you can "span" the 2 1TB drives into 1 2TB DRU, this way you can recover the 2 1TB drives with one PPU http://wiki.flexraid.com/2011/03/26/what-is-dru-spanning/

 

Here is a part of a tutorial im working on, it should give some more insight. 

---

What is FlexRAID?

FlexRAID is a paid software RAID solution, it is multiplatform but you will mostly find it on windows systems. it uses “snapshot” RAID opposed to “real-time” RAID, making it suitable for data that does not change very often. In case of a disk failure it will only restore the data that was present during the last snapshot. You can set up your own snapshot schedule.

There are 3 versions of FlexRAID:

1.    Data Protection $40 (no storage pooling)

2.    Storage pooling $30 (no data protection)

3.    Combo $60 (duh, it’s the combo version :p)

 

This topic is about the Combo version.

 

FlexRAID Pro’s and Con’s

Before we start with the tutorial it’s probably a good idea to list the pros and cons of FlexRAID.

 

Pros:

·         Existing data on drives stays intact when creating the array/pool.

·         You can expand the array without data loss or rebuilds.

·         Only active disks will spin up (power efficient)

·         Multiplatform (but to be fair, I wouldn’t use it on Linux)

·         Uses NTFS, so if the array fails you will still have your data in NTFS on the disk.

·         Entire files are always stored on a single disk, not spanned across multiple

 

Cons

·         Speed is the same as a single disk.

·         Disk load is not balanced

·         Entire files are always stored on a single disk, not spanned across multiple

 

As you can see “Entire files are always stored on a single disk, not spanned across multiple” is listed as both a pro and a con, personally I think it’s a pro because there is a smaller chance of corruption.

But others can see it as a con because it may increase the chance of a faulty recovery.

 

 

So when should I use FlexRAID and when should I not?

FlexRAID is very well suited for media storage and simple “copy paste” style backups and other data that does not change often.

In that scenario it will be more then fast enough and it will also be very efficient.

 

But as I mentioned before, FlexRAID does not split files, so very large files can cause problems if they are larger than the drives that form the array/pool. It’s also not the fastest RAID solution out there.

 

So use it for:

·         Media storage (photo’s, (HD) movies, audio)

·         Copy paste style backups (so not backup images, unless they are small)

 

And don’t use it for:

·         Very large files (iSCSI targets, Large VM’S, verry Large backup images)

·         High I/O applications (don’t use snapshot RAID for this)

 

If you’re not sure that FlexRAID is the right solution for you then then make a post in the storage subsection and ask for advice there ( type @looney in your post to automatically send me a notification of your topic)

[crazy_104]

Is FlexRaid compatible with WHS2011?

 

Does this have (more or less) the same functionalities as the defunct Drive Extender?

[sNaKeBiTe]

Alright, thank you! :D