NAS JBOD or SPAN? Experiences or preferences?

forgotmyname

About to add an additional drive to my DLINK NAS.

I dont need mirroring or parity. The truly important stuff is backed up to an external device. As well as another backup onto a 2nd PC.

What i do not want though is for one drive to fail and to corrupt the other drives so no stripe. My main drives in my PC are RAID 0 stripe and although its fast and compares to my new SSD it has caused issues over the years when trying to image the OS etc.

Seems making a usable image from a RAID setup defeated me. Although its supposed to be possible.

Anyway back to the NAS JBOD or SPAN? Advantages and disadvantages of each?

Thanks

John_Gray

forgotmyname wrote: »

Anyway back to the NAS JBOD or SPAN? Advantages and disadvantages of each?

I would respectfully suggest that this is an ideal question for Mr Google...

forgotmyname

Oh yes, I have done that. RAID 10 ...RAID 10.. you need raid 10...

Except err NO i dont need raid 10

Not found anything where someone actually posts their thoughts on having a spanned drive and whether its better or worse.

The main use if media storage for KODI. Will an extra drive letter be better as a stand alone drive or as a spanned drive with the same drive letter?

Johnmcl7

Have you checked what options your Dlink NAS offers?

JBOD is a fairly general term that usually refers to a set of drives that aren't using a RAID configuration or similar, you can use spanning so rather than each drive appearing individually you see them as one large drive. You'd need to check what your NAS offers as the advantages and disadvantages will vary depending on the implementation. Spanning is more convenient than having the drives configured individually as it shows as a large single pool.

I use Windows Home Server and on their older OS used their drive spanning technology called Drive Extender which meant all four drives looked like a single large drive plus when I added more drives, it simply extended the capacity. However MS removed the technology from their newer version of WHS v2011 so I have the drives simply running individually which can occasionally be a pain when one folder gets too big and needs moved to another drive but that's rare. I thought I'd miss the spanned volume but at least in this case, not having the spanning was quicker and I like choosing exactly what's on each drive as it makes the management easy particularly when it comes to upgrades.

John

forgotmyname

Thats what i was wondering, what experience people had of sanning over having an extra drive letter for the new drive.

DLINK NAS info does not mention of losing data on the 2nd drive if the first one drops out etc.

Speed implications of spanned over another drive letter?

When Media Center or KODI will is think thats a big drive and take ages or same as scanning 2 drives.

Seen comments on do this and do that but not one that says i chose spanning and then swapped because....

bluesnake

when you run into multiple disks, common wisdom says recovery, so raid 0 is not that popular

This product apparently keeps all your data together - lime technology unraid, and you can mix and match disk sizes

If I had to create a raid, probably would choose zfs on linux.

Johnmcl7

forgotmyname wrote: »

Thats what i was wondering, what experience people had of sanning over having an extra drive letter for the new drive.

DLINK NAS info does not mention of losing data on the 2nd drive if the first one drops out etc.

Speed implications of spanned over another drive letter?

When Media Center or KODI will is think thats a big drive and take ages or same as scanning 2 drives.

Seen comments on do this and do that but not one that says i chose spanning and then swapped because....

You wouldn't lose data on the second drive if the first drive failed unless they were configured as RAID 0. The speed implications will depend on how Dlink handle the spanning, if there is no performance difference then Kodi will take the same time to scan a spanned volume as it would a pair of individual drives. Kodi should be able to handle the multiple drives seemlessly as you can simply define additional libraries which Kodi will merge as one collection.

John

forgotmyname

Yeah im going for the multiple drive option. No issues with any data spanning 2 drives then.

As you say all it requires is an addition drive listed in KODI and it wont care what files are where.

Thanks

debitcardmayhem

More importantly, JBOD does not offer the redundancy of RAID. If a disk is corrupted in a JBOD array, all your data is at risk, including what’s on the other drives. With RAID, you can lose one or more disks and still preserve your data, depending on the configuration.

quoted from ..http://www.acnc.com/blog/jbod-vs-raid-cost-effective-network-storage-options/

If you use spanned where is the filetable stored if a file is stored on two physical disks what then ?

Johnmcl7

debitcardmayhem wrote: »

quoted from ..http://www.acnc.com/blog/jbod-vs-raid-cost-effective-network-storage-options/

If you use spanned where is the filetable stored if a file is stored on two physical disks what then ?

That quote is not correct for JBOD in general, when a drive has failed in a JBOD configurations I've worked with using spanned disks that data has gone as you'd expect but the rest of the array has functioned as normal. Even with the hardware down, it's been possible to retrieve the data manually from another system.

As I've mentioned above though it's always worth checking how the specific implementation for that device actually works as they're not all the same and there may be specific JBOD implementations that risk the whole array on a drive failure but it's not the case for all of them.

John

forgotmyname

I went with a new standard drive.

With JBOD and a spanned drive, when drive 1 fills it carries onto drive 2 as if it were the same drive. Say there was 2GB left on drive 1 and i saved a 10GB file.

Would it save to drive 2 or separate the file partially onto 1 and partially onto 2?

I would imagine that only that one file would be at risk, the files on the remaining working drive will be safe.just the one spanned file at risk?

As well as the data loss on the dead drive of course.