TS451 - upgrading drives / raid keeping the data

[kop-95]

Hello,

I have a TS451 filled with 4x 1 TB HDDs RAID 5, nearly full.
I would like to upgrade to a 2x 6 TB Raid 1 plus 2x 128 GB SSD for caching.

I am wondering how I could make it without loosing data.
Does anybody have an idea ?

Is that working :
- copy all the data to one of the 6 TB disk through USB
- stop the NAS and remove all 1 TB HDDs
- insert the 6 TB disk (clean without data) as a JBOD disk
- copy back the data from the external USB drive
- insert the other 6 TB drive to create the mirror (after copying the datas)

Thanks for your help ?

[Don]

Backup data. Recreate system from scratch. Restore data.

[kop-95]

Thanks Don.

But that would mean having a third HDD for backup.
Is my method described working ?
- backup all the data through USB
- stop the NAS and remove all 1 TB HDDs, restart system from scratch
- insert one 6 TB disk (clean without data) as a JBOD disk
- copy back the data from the external USB drive
- insert the other 6 TB drive to create the mirror (after copying the datas)

That would mean I can use one of the 6 TB HDDs as a temporary external drive for backup/restore

Thanks

[Don]

It will work but not advisable. If something goes wrong after you insert the second drive while the raid is building you will lose you data as you don't have a backup. You should be doing backups anyway so why not get a drive for that purpose. See my signature.

Also what are you using your system for that you think caching will be of benefit?

[kop-95]

OK thanks for the advice.

I use the NAS for backups, large directory syncing, and multimedia files sharing.
But I have a low speed (below 15 MB/s), even on 1 Gb network (wired). I thought that HDDs were the bottleneck, but not easy to diagnose.

[Spider99]

i would sort the network issue first before you do anything - the cache will not help your network speed

are you sure all your network and router are 1gig sounds more like 100mbit

[Don]

i would sort the network issue first before you do anything - the cache will not help your network speed

are you sure all your network and router are 1gig sounds more like 100mbit

Agreed. I doubt this is a disk transfer speed issue unless of course the drives are really really old and transfer at SATA I speeds.

[kop-95]

computers, NAS and network switch are 1 Gb - verified on the switch management interface
Tools used for transfers are TimeMachine on Macos Sierra, Robocopy on WIndows (through SMB shares), or Windows explorer copy (Windows 7).

Disks are SAMSUNG HD103UJ (SATA 3 Gbps)

[Spider99]

download the qnap diagnostic tool and test your disks

what speeds do you get?

do you have encrypted volumes or folders? have seen poor network performance due to folder encryption 40MB/s vs 110MB/s on same nas

[kop-95]

I have no encrypted volumes.

I have between 80 and 105 MB/s on my 4 HDDs, I assume I should have better perfs on my shares.

[Spider99]

not great speeds but adequate

do a simple test - copy the single largest file you have from the nas to a pc/mac and then copy it back

what network speeds do you get and how big is the file