And what specifically is wrong with flexraid ? Is there a reason why you seek an alternative ?
I'm not aware of a better option.
Depending on what he wants he can use SnapRAID or disParity. Both are good alternatives to the snapshot parity portion. I suspect he is confused by the complicated and odd naming scheme used by the creator of FlexRAID and / or wound simply want to compare it to other programs like it to make an informed decision. You are right, though, there is nothing else out there that does everything FlexRAID does.
For flexraid you can choose F or T
T is real time
F is snapshot
I've been following a lot of FlexRAID vs... threads.
I'm wondering why people look to use FlexRAID and something like Stablebit Drivepool together? Clearly FlexRAID-F can offer parity protection and pooling in one, and it seems like Drivepool provides more data protection than flexraid in many ways once you setup duplicated folders. Since a duplicated folder exists on 2 drives at once, and is written that way in realtime, you won't lose any data if a drive fails. Whereas with FlexRAID, it is entirely possible to lose data if a drive dies before an update operation...
I'm currently trialling FlexRAID, and although I do like it, I did some test array rebuilds and found the process to be a bit clunky, and I still get sporadic update/validate/verify errors every now and then and so I'm considering moving to Stablebit and just having all my critical data exist in duplicated directories. Although this is less drive-efficient, my storage requirements aren't huge <4TB, and drive space is cheap...
Any reason I shouldn't make the switch?
I don't think I'm paranoid. Last night's update and validate both failed. I'm looking into why now.
Essentially though, since these volumes are used for backup and media storage, including as a crashplan destination, I think things change too frequently and sometimes during the update window. More investigation is required.
Its also irritating that FlexRAID doesn't include the snippet of the log file explaining the failure when you get one. I travel a lot, and so I end up having to VPN in to have a look at the logs and sort it out etc... I feel like something that just does simultaneous writes to 2 drives is going to avoid these issues, more like conventional RAID.
Makes sense. Thats my basic requirement too.
I've just re-run the flexraid update/validate processes and the both passed. I stopped the crashplan service during this time.
Part of the issue is that the Update/Validate/Verify procedures all take quite some time. Especially as you add more data. If you change something in the pool in between an update and verify for example, then the process will fail, although there is actually nothing wrong with your data, its just not currently in a synced state. However, this behaviour means that if there actually were any issues with the data on the drives, you wouldn't know, because the operation would fail anyway. You might be able to glean more info from the logs however.
In short, it seems that FlexRAID is a great solution for data that doesn't change much, but for Crashplan backups, it seems like a bad choice, since my backup data changes all the time.
Thats why I have started investigating other options.
Otherwise the solution is to pause all services that access those drives during the update/validate/verify window, which probably means stopping them for 3 hours or so
I run crashplan as well. I don't remember it ever causing an error. In fact when I first used crashplan it took a few weeks to upload all my data and I don't recall having issues. All crashplan does is read your data and upload it, correct? To the best of my knowledge that shouldn't cause errors.
If you're backing up your server to Crashplan, then yes, its just uploading compressed data. However, I use my server as a Crashplan destination for my Laptops. So Crashplan receives backup data from my other machines over wifi and stores it on my FlexRAID volume. This is the cause of the problem I think. I'm not actually using Crashplan to send data to the cloud (yet), mainly because my ADSL upload speed is just too slow.
Real-time could be the solution. I will investigate this. One of the things that attracted me to Stablebit drivepool is that it essentially emulates real-time RAID through software, while allowing me to dynamically expand the disk pool whenever I like.
In the future, I fully expect to move to a 2-box solution. One machine dedicated to the always-on server tasks and NAS duties, and the other a HTPC / utility machine. But for the mean time, I like the 1-box approach. I just need to get the kinks in the storage system ironed out
All this being said though - I think FlexRAID is great, and works very well. Having to sort out a few scheduling issues is a small price to pay for the performance gains of snapshot raid vs real time raid.
If all I wanted was redundancy, I could just setup the microserver BIOS to do 2 RAID 1 pairs out of 4 2TB drives and leave it at that... I'd rather have some of the flexibility that FlexRAID will bring in the future when I start wanting to introduce bigger drives etc...
Quick Question (Sly Assassin can probably answer this)
Does FlexRaid T/F work with entire HDDs or with partitions.
The reason I ask is my HTPC setup is as follows
120GB SSD, 4x3TB + 1x4TB HDDs
I wish to use a 3gb partition on the 4tb drive for parity.
I wish to use the remaining 1tb partition for torrent downloading (The 120gb ssd is too small for torrents)
I'm currently using snapraid, but I'm thinking of switching to something with drive pooling. I'm undecided whether i will stick with snapshot or if I will switch to t-raid, it's kinda annoying to have to schedule backups, it'd be nice if it was always automatically up to date.
HTPC (MediaPortal) / Pioneer SC LX87 / Wharfedale Jade 7 Fronts, 5 Rears, 2c Center / DIY Sub
I haven't ever tried this personally so that's all I can say. This example is one of the reasons though why users might want to have a drive outside of their pool/array.
Recording WHS shows is another reason. It doesn't work particularly well in flexraid t either from what I have read.
Is it because it is not Windows based?
There doesn't seem to be any of these issues with the FlexRAID (T/ F) in ZFS... parity data is written on the fly when adding or deleting files and you can use an SSD for cache if you want...
Okay, you can't add a new drive once the pool is set up, but from what I have been reading about FlexRAID et al, ZFS does not seem to require one third of the maintenance needed for FlexRAID...
Just my thoughts BTW...
Flex(t) which works in real time should solve most of your issues. Another option, is Windows Storage Spaces. WSS turned out to not be the overall best solution for my server, but a lot of that had to do with the size of my array and what specifically I am using my media server for. If you are using your small(ish) system to simply handle being a backup server for your laptops, WSS might not be a poor solution for you. It will pool your drives and it will also do simple (no redundancy), 1-mirror, 2-mirror, and parity. If you're running Windows 8, you already have it too.
As for T, PPUs in Windows must be RAW and unformatted. In Linux they should have a partition table but no partitions or data. Neither case can they contain a partition, so for your intended usage (leaving 1TB partition for downloads) you would need to go with Raid-F