Can Single File Span Multiple Physical Drives?

[preiner]

Hi,
I have a new system with 2 LSI controllers (currently in IT mode but could be in raid) with 16 drives (some 4TB some 10TB some 18 TB)

Is there any way to get ZFS and/or TrueNAS to support a single file that is too big to fit on one drive.

For example, my full backup is about 25 TB with incrementals being very small. I cant split the full backup into chunks. I must have one logical volume than can somehow span/stripe that large file across multiple drives.

For the moment, I dont want to introduce redundancy. That further complicates the solution. If there is no way to span, then redundancy is irrelevant.

If you know of some other solution, please let me know.

Thanks and Best Wishes

 

[jgreco]

currently in IT mode but could be in raid

No, it couldn't. Please refer to

What's all the noise about HBAs, and why can't I use a RAID controller?

1) An HBA is a Host Bus Adapter. This is a controller that allows SAS and SATA devices to be attached to, and communicate directly with, a server. RAID controllers typically aggregate several disks into a Virtual Disk abstraction of some sort...

www.truenas.com

Is there any way to get ZFS and/or TrueNAS to support a single file that is too big to fit on one drive.

ZFS is an integrated filesystem and volume manager. The size of a drive plays no particular issue in what ZFS can support; the Z in ZFS stands for Zettabyte which is an indication of the sort of scope that ZFS is capable of dealing with. At this time it is probably not practical to hook up more than a few thousand drives to a host system, and with the largest drive size out there being 22TB today, that means that there's probably a practical limit of about 90PB of storage on a single system. ZFS won't care if that's one big file or billions.

For the moment, I dont want to introduce redundancy.

Generally speaking, the redundancy a pool is born with is not alterable after the fact. In some cases, such as mirrors, it is possible to widen a mirror, and RAIDZ expansion is theoretically coming someday, but it isn't generally possible to introduce arbitrary changes in the redundancy architecture down the road.

 

[Davvo]

ZFS Primer

Background information about the Zettabyte File System (ZFS).

www.truenas.com

Introduction to ZFS

This is a short introduction to ZFS. It is really only intended to convey the bare minimum knowledge needed to start diving into ZFS and is in no way meant to cut Michael W. Lucas' and Allan Jude's book income. It is a bit of a spiritual...

www.truenas.com

 

[ChrisRJ]

For the moment, I dont want to introduce redundancy. That further complicates the solution.

How does it makes things more complicated?

We relatively frequently have people who claim that redundancy is not needed, because the system in question is "only" for backup. I strongly disagree, because your backup is your last line of defense. It is typically needed when not one but several things have gone badly wrong.

Can you share more details about your use-case? That will make it easier to give proper recommendations. Also, please check the forum rules about what information about system should be shared to get the best possible advice.