RN202 backup / snapshots

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2ndNAS wrote:

The DUO does not support snapshots, but given that snapshot pointers are kept in folders:
Are snapshots also copied to the DUO (un-usable on the DUO), so a restore also restore the snapshots?

The shouldn't be copied. If you make snapshots accessible in the UI, some backup methods might copy them (not sure).

It would be very bad if it did. If you had a 500 GB folder with 20 snapshots, you'd need 10 TB of space to back them up. The CoW efficiency wouldn't be preserved.

So it's not practical to back up snapshots on the duo.  If you did incremental backups to another OS 6 NAS, you'd get new snapshots on the backup NAS, which is probably close enough to what you want if you do the backups often enough.  Even with another OS6 NAS you can't back up the original snapshots.

If not, I might drop RAID 1 and choose 2 separate drives in RN202, use the first disk as the Primary disk
and the second disk for manually backups of the Primary disk.

I suppose I need a backup procedure (that supports snapshots) in the rn202 for this?

 

You could do this, though  I am thinking it is less desirable than RAID-1.  RAID-1 provides redundancy for the full share (including all the original snapshots).  If you did weekly incremental backups,  then anything that is replaced on the backup drive in each backup ends up in a snapshot on the second drive.   If you change something twice during the week, then the intermediate version never ends up on the backup device.

That's because there is no way to back up the original snapshots efficiently - the best you can do is create new ones.

So I'd stick with RAID-1 on the RN202.

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Some of my files are photos, and they contain (in the internal EXIF info) the timestamp when the photo was taken.
If you adjust the colors (that is, update the photo) and save the result, the file timestamp may be set to the original timestamp.
Will OS6 detect, that the photos are updated and keep a snapshot of the original?

The primary storage on the OS6 system will work properly (the unadjusted copy remains in the snapshot).  That's because the writing of the updated file's data blocks is what unlinks the snapshot version from the updated one (CoW - copy on write).

But if the file is the same size, and has the same metadata, then an incremental backup might not detect the change, so it is possible it won't get backed up.  I'd suggest using rsync for backup (and also try adjusting the colors on a test file, and see if the backup detects it).  I think it will (it seems to me that the photo's modification timestamp will be updated, so the metadata won't be unchanged).

Hello StephenB,

and thank you for your reply.

I was naive, but hoped to backup the snapshot pointers in the snapshot folders to the DUO, which would not understand their purpose, just keep the pointers as data until they were restored to rn202; but even if it worked, I wondered if the pointers would become invalid if I ran defrag on the new rn202.

I hope to receive the new NAS tomorrow, will insert a single disk and play with it. Hope it gives me a better understanding of the new OS.

Hello StephenB,

and thank you for your reply, I was expecting something like files with sector numbers.

Have received my rn202, and have completed the initial setup.

Is there a User Guide for the rn202 (I have one for my DUO (ReadyNAS_UM_02Apr08.pdf)?
Or perhaps an URL with the documentation that are relevant?

Had a look into the snapshot folders, and it's overwhelming to see the contents.
Found that snapshots are taken even during nighttime disk spin-down periods, so
changed snapshots to Daily.

I went into Shares->Browse and chose my Backup share, and then selected Recover.
Stared at the menu: How come there were only 3 snapshots after HOURLY snapshots all night?
After a lot of confusion I found there was a hidden scroll bar inside the menu.
Would it be possible to keep them visible all the time, please? OS version is 6.3.2.
FWIW: Scroll bars exist when I work with the DUO....

Next day I discovered that the Daily snapshot at midnight was not taken.
Is there a procedure to change the snapshot frequency?

The Test Connection button (on remote Backup Source menu) successfully connects,
but backup terminates with error. Filenames are read correctly, but can't copy?
(On DUO, NFS is started, and under Shares->NFS Default access is set to R/W)
   Backup Job Name: \\NAS1\backup to \\NAS2\backup
   Backup Job Type: Full
   Protocol: nfs
   Backup Source: [remote:nfs]/10.0.0.101:/backup
   Backup Destination: [Backup]/
   Backup Start Time: Fri Nov 13 2015 17:23:12
   Backup Finish Time: Fri Nov 13 2015 17:23:15
   Backup Status: Fail: failure during copy.

   Cannot read 76161740.jpg
   Cannot read B_.BIN
   Cannot read FreeDOS WDIDLE3.iso
   Cannot read GRMSDKX_EN_DVD.iso
   Cannot read GRMWDK_EN_7600_1.ISO
   Cannot read KIDs.TXT
   Cannot read ubcd511.iso
   Cannot read wdidle.iso
   ----------------------------------------

I can't enable RSYNC in Shares->Shares->Home Folders->Settings->Access.
It is possible to enable RSYNC for my Backup share. Have I forgotten something ?

Does RAIDar60  support the DUO?
Does RAIDar438 support the RN202?

It would be convenient if OS6 supported an option to create an automatic snapshot
for the duration of a backup to another server. Would this qualify as an Enhancement Request?

Thank you in advance

DuoNAS