Pillar · Offsite backups
The 3-2-1 rule, the protocols each NAS speaks, four kinds of target, what a terabyte costs in each, and how long the first copy takes.
Quick answer
What is the best offsite backup for a NAS?
The best offsite backup for a NAS is a versioned, encrypted copy in another building, on a target the NAS already speaks: an rsync server over SSH, a restic or Borg repository, or S3. Basalthold rents storage servers for it from $110.99 per 30 days for 24 TB (price of 2 November 2026), crypto only, no KYC.
| Rule to follow | 3-2-1: three copies of your data, on two different media, one of them offsite |
|---|---|
| Synology | Hyper Backup to an rsync-compatible server (SSH or rsync daemon) or to S3-compatible storage |
| QNAP | Hybrid Backup Sync 3: versioned jobs to another QNAP or to cloud services; rsync servers as sync targets |
| TrueNAS | ZFS replication over SSH, rsync tasks, or cloud sync tasks to S3, B2 or SFTP |
| Unraid and plain Linux | restic, Borg, Kopia or rclone, run from a container or the shell |
| What Basalthold rents | Storage dedicated servers: a whole physical machine built around a bank of hard drives, rented to one customer, with root access to every drive |
| Capacity | 24 TB to 160 TB of hard drives, raw |
| Drives at delivery | The operating system sits on its own SSD (two mirrored SSDs on the larger holds); the data drives arrive blank and unpartitioned, so you can build ZFS, an mdadm array or a set of independent disks. If you want the team to prepare a RAID 6 or RAID 10 array before delivery, say so to support before the server is handed over |
| Encryption | You can encrypt every data drive with LUKS or ZFS native encryption; the keys stay with you and nobody on the team ever asks for them |
| A copy of your copy | A storage server is not a backup of itself: we keep no copy of your data anywhere else, so a second copy in another place stays your job |
| Payment | Crypto only: BTC, USDT, USDC, ETH, SOL, LTC. No KYC: no ID, no selfie, no documents, no card and no phone number, at any point |
An offsite backup is a copy that survives the loss of the building your NAS sits in. Fire, theft, a flood or ransomware on the home network can take the NAS and its local copies together.
RAID does not help here. It keeps the array running through a dead drive, and it writes a deletion to every drive at once.
Backblaze sums up the 3-2-1 rule as three copies of your data, on two different media, with one copy offsite. For a NAS owner, that means the live data, a local copy on a USB drive or second volume, and one copy elsewhere.
A NAS holds one copy of your data, not a backup of it; the offsite copy is the one that survives the bad day.
Pick a target your NAS backup tool supports natively, then run that service on the server.
| NAS | Built-in tool | Offsite targets it supports | What runs on the server |
|---|---|---|---|
| Synology (DSM 7.2 to 7.4) | Hyper Backup | rsync servers, remote Synology NAS, S3 and S3-compatible storage, cloud drives | OpenSSH and rsync (port 22), or an rsync daemon (port 873), or an S3 server |
| QNAP | Hybrid Backup Sync 3 | Versioned backup to another QNAP (RTRR) or cloud services; sync jobs to rsync, FTP, SMB or WebDAV servers | rsync over SSH for sync jobs |
| TrueNAS | Replication, rsync and cloud sync tasks | ZFS replication over SSH; rsync in module or SSH mode; S3, B2 or SFTP cloud sync | ZFS and SSH, rsync, or an S3 server |
| Unraid or any Linux machine | restic, Borg or Kopia, in a container or the shell | SFTP, Borg over SSH, REST server, S3 | SSH, rest-server or an S3 server |
From Synology's Knowledge Center and DSM 7.4 specification, QNAP's Hybrid Backup Sync page and TrueNAS documentation, read on 2 November 2026.
Hyper Backup's rsync wizard has two modes; the guide to backing up Hyper Backup to a rented rsync server covers both. TrueNAS users with encrypted datasets can replicate with zfs send --raw: OpenZFS says the receiving machine never gets the keys.
Four designs cover almost every NAS. They differ in who keeps the versions, who holds the key, and what a stolen NAS password can delete.
| Target | Versions kept by | Encryption key held by | Best for |
|---|---|---|---|
| rsync over SSH | Hyper Backup's multi-version .hbk files, or ZFS snapshots on the server | Your NAS, with Hyper Backup client-side encryption | Synology, QNAP sync jobs, TrueNAS rsync tasks |
| restic or Borg repository | The backup tool, with deduplication | The client: always for restic, by choice for Borg | Unraid, TrueNAS, Linux and mixed fleets |
| S3 on your own server | The backup tool, plus S3 versioning where the server has it | The backup tool | NAS apps that only speak S3 |
| Cloud object storage | The backup tool | The backup tool | Small data sets and no server to run |
restic encrypts every repository, while Borg asks you to pick a mode at borg init. The trade-offs are on restic or Borg for offsite backups. For S3, hosting your own S3 storage on a rented server compares the servers that run on one machine.
Cloud object storage bills per terabyte stored; a rented server bills per machine, whatever you put on it. Below a few terabytes the cloud is cheaper. Past that, a whole server costs less per terabyte.
Of 23 storage-server sellers Basalthold checked on 2 November 2026, 16 accept crypto; only 5 offer one with no ID check, monthly billing and stock. Their median for 16 TB or more was $9.50 per TB a month.
| Target | Price per TB per month | Pay in crypto | What you get |
|---|---|---|---|
| Basalthold Hold 160 | $3.50/TB raw | Yes, no KYC | 10 × 16 TB HDD, a whole machine |
| Basalthold Hold 100 | $3.77/TB raw | Yes, no KYC | 10 × 10 TB HDD, a whole machine |
| Basalthold Hold 24 | $4.62/TB raw | Yes, no KYC | 2 × 12 TB HDD, a whole machine |
| Median no-KYC crypto storage server, 16 TB or more | $9.50 raw | Yes | 5 hosts in the survey pool |
| Hetzner Storage Box | $2.27 to $3.58 | No | Network storage over SFTP, SMB or rsync, not a server |
| Backblaze B2 | $6.95 | No | Object storage, billed per TB stored |
| Wasabi | $7.99 | No | Object storage, billed per TB stored |
Prices checked on
Servers are priced per TB of raw disk, cloud services per TB stored. Public pages read on 2 November 2026; euros converted at 1 EUR = 1.1172 USD (ECB, 2026-10-30). For Hold 100 and Hold 160, the survey found 1 host with a comparable plan: OffshoreDedi.
Parity takes its share of raw disk. Ten 10 TB drives in RAIDZ2 keep 80 TB for data; ten 16 TB drives keep 128 TB. Hetzner's Storage Box is the cheapest line in the table and needs no administration. It cannot be paid in crypto, though, and Hetzner may request identification. The full cost comparison is on a rented storage server against Backblaze B2 and Wasabi.
The first copy is the slow one; later runs send only what changed. Two links set the pace: your home upload and the server's port. Every hold has a 1 Gbit/s port.
These figures are calculations, not measurements. A 1 Gbit/s link at full rate moves 125 MB per second, or 10.8 TB a day. Most home uploads are far slower, so seed the copy over days or weeks and keep the local copy meanwhile.
| Home upload | Data per day | 10 TB | 50 TB |
|---|---|---|---|
| 50 Mbit/s | 0.54 TB | 18.5 days | 93 days |
| 100 Mbit/s | 1.08 TB | 9.3 days | 46 days |
| 500 Mbit/s | 5.4 TB | 1.9 days | 9.3 days |
| 1 Gbit/s | 10.8 TB | 0.9 days | 4.6 days |
Bits per second × 86,400 ÷ 8, in decimal terabytes, without protocol overhead; real transfers are slower.
Traffic counts as well as speed. Every server has a 1 Gbit/s port with a monthly traffic allowance (Hold 24 40 TB, Hold 40 60 TB, Hold 100 120 TB, Hold 160 200 TB), one dedicated IPv4 address and an IPv6 /64; going past the allowance never triggers an automatic bill.
Two settings matter more than the target: the NAS must not delete old versions, and the key must never leave your side.
Encrypt on the NAS and lock old versions on the server, and the offsite copy survives both a burglar and a stolen password.
Hold 24 mirrors its two drives for 12 TB usable, enough for a small NAS with versions. Hold 160 has the smallest price per TB of the four holds. Terms of 3, 6 and 12 months are on the hold price list.
24 TB raw · 6 cores
$110.99
$99.89 / month
$299.67 for 3 months
$88.79 / month
$532.75 for 6 months
$77.69 / month
$932.31 for 1 year
3 months $299.67 (−10%)6 months $532.75 (−20%)1 year $932.31 (−30%)
40 TB raw · 6 cores
$201.09
$180.98 / month
$542.94 for 3 months
$160.87 / month
$965.23 for 6 months
$140.76 / month
$1,689.15 for 1 year
3 months $542.94 (−10%)6 months $965.23 (−20%)1 year $1,689.15 (−30%)
100 TB raw · 10 cores
$377.05
$339.34 / month
$1,018.03 for 3 months
$301.64 / month
$1,809.84 for 6 months
$263.94 / month
$3,167.22 for 1 year
3 months $1,018.03 (−10%)6 months $1,809.84 (−20%)1 year $3,167.22 (−30%)
Most TB per dollar
160 TB raw · 16 cores
$561.39
$505.25 / month
$1,515.75 for 3 months
$449.11 / month
$2,694.67 for 6 months
$392.97 / month
$4,715.67 for 1 year
3 months $1,515.75 (−10%)6 months $2,694.67 (−20%)1 year $4,715.67 (−30%)
In every plan: Blank data drives · Encryption keys stay yours · Dedicated IPv4 · No logs · No KYC · No setup fee
No. RAID keeps the volume online when a drive dies. It copies every change, including a deletion or an encryption by ransomware, to all drives at once. A backup is a separate copy with older versions, ideally in another building.
Yes. Hyper Backup treats a Linux server as an rsync-compatible server. Use remote shell mode over SSH on port 22 with transfer encryption, and choose multi-version backups so client-side encryption and rotation are available.
It depends on how much you store. B2 costs $6.95 per TB stored a month, so a few terabytes cost little there. A hold costs the same however full it is: $3.50/TB raw on Hold 160.
Not if your NAS encrypts them first: we then store only encrypted files. You can encrypt every data drive with LUKS or ZFS native encryption; the keys stay with you and nobody on the team ever asks for them. We do not inspect the contents of your drives.
Yes, through Samba. Time Machine accepts an SMB share set up with Samba's vfs_fruit module, kept in its own dataset with a size cap. The setup is on can Time Machine back up to a remote Linux server?.
Give your NAS a copy in another country
Hold 100: Intel Xeon Silver 4210R (10 cores / 20 threads), 128 GB DDR4 ECC, 10 × 10 TB hard drives (100 TB raw) plus 2 × 480 GB SSD for the system, mirrored, 1 Gbit/s port with 120 TB of traffic per 30 days, 1 IPv4 and an IPv6 /64, for $377.05/30 days. Same price in Amsterdam, Bucharest and Chisinau; crypto, no KYC.
24 TB from $110.99/30 days · no KYC
Choose a hold