DSM 5.2 Super Slow Backup to Seagate Expansion Desktop (SMR) Drive

[Schmill]

Ok, first things first, I know SMR drives aren't intended for daily use etc. due to the way that they record data, but all that I'd read seemed to say that they were well suited as backup drives.

 

So I have a Seagate Expansion Desktop 6TB drive (USB3 connected, and externally powered) running through a USB3 card to backup my DSM 5.2 system... but it is horrendously slow.

As in I started the backup over 38 hours ago, and so far it has managed to backup (DATA backup, not LUN) just 585 GB.

I am using an N54L as my hardware platform - but is there any issue with the 5.2 software using SMR drives? It works fine with other USB3 drives (so I know its not the interface card), but I suspect that they are PMR, so does the OS having any issues with SMR, or is it literally going to be down to the drive itself? (In which case I'll have to return it and purchase a much more expensive alternative  )

 

Thanks for any info!

[IG-88]

this disks usually have a xxGB area with PMR and the rest is SMR, in kind of desktop usage cases the PMR area softens the blow but using it for backup and a huge ammount of samll files (like using it with rsync) might result in lowe performance

your ~5 MB/s seem pretty low  but it might depend on the backup software and just using rsync might be the worst scenario

with the right backup software and incremental backups it might be no problem but if you want it careless then spend a few bugs extra for a smr drive, it not that much

 

you might read this (and there are more articles about that)

https://www.storagereview.com/seagate_backup_plus_external_hard_drive_review_8tb

[Schmill]

12 minutes ago, IG-88 said:

this disks usually have a xxGB area with PMR and the rest is SMR, in kind of desktop usage cases the PMR area softens the blow but using it for backup and a huge ammount of samll files (like using it with rsync) might result in lowe performance

your ~5 MB/s seem pretty low  but it might depend on the backup software and just using rsync might be the worst scenario

with the right backup software and incremental backups it might be no problem but if you want it careless then spend a few bugs extra for a smr drive, it not that much

 

you might read this (and there are more articles about that)

https://www.storagereview.com/seagate_backup_plus_external_hard_drive_review_8tb

 

Thanks for the reply IG-88, is this PMR area 'visible', or is it (as I expect) hidden by the drive and only accessible / managable by it?

I am using the default "Backup & Replication" utility on the Synology software, but don't know what it uses underneath. The backup is of the entire server, so there is a mixture of large media files, as well as smaller (and plentiful!) files like mp3s, documents, and jpg photos.

 

I too thought that as a backup it would be ok, since the SMR wouldn't be having to do its re-write behaviour, but it seems that is not the case. Bursty writes (with associated idle times) seems file, but the constant (sequential?) writing of an large file-by-file backup seems to give it a real headache...

 

I did read several reviews before purchase, and all seemed to indicate that it was good for backup, bad for daily usage, but I'm wondering if by "backup" they actually meant copying a few files to it for "archive" every so often, rather than a true "tape-like" bulk backup.

[IG-88]

13 minutes ago, Schmill said:

Thanks for the reply IG-88, is this PMR area 'visible', or is it (as I expect) hidden by the drive and only accessible / managable by it?

they are not telling you how big it is but  usually the write speed drops when its filled up so it can be roughly mesured

i dint expect it to manageable but never looked for something like that

i thought that smr drives where already outlived as there are 16TB pmr disks

[Schmill]

To be honest, I think it would be a lot better if SMR drives were outlived, but it seems not...

This is what I bought, and SMR is the only thing I can think of to cause such a significant slowdown:

https://www.amazon.co.uk/Seagate-Expansion-External-PlayStation-STEB6000403/dp/B07C7V494X

 

Any PMR external desktop drives of ~6TB that you'd recommend as a replacement?

[IG-88]

29 minutes ago, Schmill said:

Any PMR external desktop drives of ~6TB that you'd recommend as a replacement?

 

no, i use a 2nd nas for backup

imho its important that you can "extract" the disk if the usb electronic fails so it should have a real sata drive in it

as the drive will not have much spin time as a nas drive i guess the brand is not that important