redundancy...

[UtwigMU]

you can crete iscsi volume on synology (very easy, about 5 clicks in web management, enter username and password). Then you can connect iscsi disk to windows. You can even mirror to iscsi - I tried this last week.

[VJ]

@Umfriend:
One more question... I assume all of the disks involved in a pool are operational when files are written to the pool. Is this also the case when files a read from the pool? Or is it possible that the other disks spin down (e.g. if you watch a movie that is on the pool with 2x duplication, are 2 disks spinning the whole time, or is one allowed to spin down)?

I'm more and more inclined to go the DrivePool route: just add 3 harddisks to the htpc, install DrivePool, set folders with different levels of duplication based on how important the files are to me (e.g. photos are very important, my CD rips in flac are quite important as it is a lot of work to do it; the mp3 conversions are not as it is just a lengthy batch process).
I am thinking of adding Docker in the mix, as it would allow an easy addition of various services without messing up Windows (I like to keep installed software on the OS to a minimum, so I can much more easily reinstall it and get it back up if necessary): Logitech Music Server, Serviio and TV Headend all exist; things like Owncloud or so could be interesting to check to provide more means of accessing files on e.g. tablets.

But it means no small computer purchase for me to play with here... I'll have to find another toy... hmm... a drone perhaps?

@UtwigMU:
What will you choose for OS / storage organization on your server?

[UtwigMU]

I plan to use FreeNAS. If that turns out to suck I'll use Centos mdraid ext4 (maybe xfs) and samba. I plan to start with 2 drives in mirror with ability to upgrade to 6 in RAID 6 (with zfs you need to move data elsewhere and recreate array from scratch).

After that I'll start to research alternative to mail+contact sync - maybe Zimbra or Kolab server. I envision to have offline legacy Windows workstation and maybe a Windows laptop post 2020 or so. A year ago or so I did some work fo Slovenian company which has 100+ cloud Linux servers, it's internationally known. They had almost all servers on nix and their desktops were about equal mix of Macs, Ubuntus and Windows.

I have two Thinkpads one running Windows (work) and other Linux (home). I find I prefer Linux for almost everything, I only use Windows laptop for photo work (simple photo work can be done on Linux and I can preview raw files), MS Office (only at work), banking (my certificate USB key doesn't work with Suse) and movies (better screen, Linux is a better media player otherwise as it stutters less). It happened I haven't booted Windows laptop for days and on my last three trips I only took the Linux laptop and was able to do stuff I wanted to do.

[Umfriend]

@VJ: I am not sure. I know that exploring a Pool will spin up all HDDs and I think streaming from the Pool will have all disks spinning as well but if you really want to know the best place to ask is their forum.

Spinning is also an "issue" when using Scanner as it polls for SMART quite often and that in itself spins up most HDDs...

Have you considered (regularly) backing up really important data externaly? How large is the data that you want to secure?

[VJ]

@VJ: I am not sure. I know that exploring a Pool will spin up all HDDs and I think streaming from the Pool will have all disks spinning as well but if you really want to know the best place to ask is their forum.

They have the file placement plugin, and it says "You may want StableBit DrivePool to write to one disk at a time in order to implement an efficient power savings policy." So perhaps there are some ways that not everything in the pool spins up. Because that at the moment seems to be my only doubt with it: noise generated by all the disks.

Have you considered (regularly) backing up really important data externaly? How large is the data that you want to secure?

Yes, this whole redundancy thing is independent of my backups. It is more an additional safeguard in case something happens between backups or even if something were to happen to the backup.

[Umfriend]

Perhaps. I am a bit skeptical about this. But really, how much I/O do you expect? And how much better would a Raid/ZFS/Storage Spaces solution work?

On redundancy, IMHO, if you have regular backups then more than x2 duplication is overkill (not counting x3 with CloudDrive if only because I do not trust CD that much). More important is that you add HDDs that are not bought simultaneously. Seriously.

[VJ]

Perhaps. I am a bit skeptical about this. But really, how much I/O do you expect? And how much better would a Raid/ZFS/Storage Spaces solution work?

Not expecting that much IO, but e.g. when I would be playing music there is no need for two hardisks to spin (noise, heat, power)... Other solutions may exhibit similar issues. But a dedicated storage server would be in a different room so the noise issue would be gone. From the stablebit forums (the spin-up question comes up often), it seems that it only spins the harddisks that are needed. So the issue might not occur (only exception would be if e.g. the music files would be spread out over distinct harddisks, but proper planning of the folder duplication settings should cover that). There was a guy who asked about for playback of an mkv file, and it turns out the meta-data file and subtitle file was on a different disk. So the folder option to keep data that is written at the same time together may be useful for this.

On redundancy, IMHO, if you have regular backups then more than x2 duplication is overkill (not counting x3 with CloudDrive if only because I do not trust CD that much). More important is that you add HDDs that are not bought simultaneously. Seriously.

The key word there is *regular*. I mean, we all plan it, but getting to do it regularly and organized is the key. I now have the idea of using my old computer as a backup location. Using an automatic script, every x days, copy data from the htpc to it (I could even set them to power up automatically to do it). Very important data (but that amount is limited) we will backup to non-connected devices (bluray and/or external usb).

[VJ]

Just curious... according to the drivepool website, it shows the free space on the pool. How can it do that when there are different levels of duplication within the pool?

[Umfriend]

Ah yes, that one... It does show the free space but not accounting for duplication. So if the Pool has 100GB free you can only store 50GB of files in folders with x2 duplication.

On the spinning thing, I wonder whether it would help to set the disk to spin down after 1 minute of idle time and whether that would have adverse effect on the life of the HDD.

[UtwigMU]

If you're really interested in low power, I'd consider 2.5" HDDs as they consume less power and they are likely more tolerant to spinning down. Remember the early Green Powers which had aggressive spindown and when run in NAS 24/7 they would spin up multiple times a day. This caused some drives to fail. I had about 5+ green powers myself and at work in the last 5 years, but I disabled spindown in all of them and had no failures. Drives coming from laptop design are probably better suited to spindowns.

[VJ]

Ah yes, that one... It does show the free space but not accounting for duplication. So if the Pool has 100GB free you can only store 50GB of files in folders with x2 duplication.

Ah, so very simple case... From the description I expected something a bit more intelligent (e.g. using the relative amount of data that is 2x or 3x duplicated and extrapolate from that).

On the spinning thing, I wonder whether it would help to set the disk to spin down after 1 minute of idle time and whether that would have adverse effect on the life of the HDD.

The question is when the disk would spin up: if you want to read a file that is 2x duplicated, does it spin up just one disk or both of them? From what I found on the forums, it may be just one.

If you're really interested in low power, I'd consider 2.5" HDDs as they consume less power and they are likely more tolerant to spinning down. Remember the early Green Powers which had aggressive spindown and when run in NAS 24/7 they would spin up multiple times a day. This caused some drives to fail. I had about 5+ green powers myself and at work in the last 5 years, but I disabled spindown in all of them and had no failures. Drives coming from laptop design are probably better suited to spindowns.

Low power is one aspect... I was more thinking about noise (htpc is in the living room) and to a lesser extent heat (as cooling also generates noise). I have 2 WD Red at the moment in that htpc, and while you hear them when they spin up, they are not noticable while in operation. So maybe it is not too much of an issue (I sit about 3m from the htpc).

[Umfriend]

Actually, I do believe that 2.5" spinners are more reliable so that may well be a good idea. They are getting quite beefy wrt capacity as well and for the use case at hand, performance is not an issue I would think. And yes, in my experience, spinners make a bit of noise spinning up and down but while in rotation they are rather quiet anyway.

[VJ]

True... but they are still more expensive per TB. But perhaps mixing them (duplicating on 2.5 and 3.5) could not be a bad idea.

I found the performance settings of DrivePool, here, and there is an option read-striping. I'm guessing that by switching that off, you'd limit the number of drives that spin while a file is read (e.g. for movie playback or when browsing through photos). A pity it is a pool-option, although maybe this is where pools-of-pools could come in handy.

[Umfriend]

Well, over here and over time we bought quite a few lappies with spinners that I replaced with SSDs so I have a couple of TB in 2.5" around

Yeah, the read striping thing... It is important to note that it does not stripe when reading single files. Any single file will only be read from one disk. DP tries to find the fastest HDD and will by preference read from there until it is busy and then start reading from the other HDD(s).

Uhm, reading it again, that is not what they imply on the page... That is weird. Either it is a newer feature or my memory is, uhm, what's the word again?

[VJ]

Our sysadmin has some bad experiences with SSD disks suddenly failing without warning. So I tend to only use them for my OS (which I can quickly get back).
A bit annoying that I have to wait one more year before I can play with it all: I still have one more year here in Santiago and the computer is in Warsaw... But not being there also limits the current need, so there is that. Still, I'm happy I started this thread because it helped me to get a clear picture of what I need/want. My girlfriend meanwhile bought an extra external disks as she needs more storage), but we can re-purpose those as backup disks later (we have a couple of them already, I also bought one here in Santiago). Looks like it then will be an upgrade year for the hptc: hardisks + video card.