RAID5 Recovery time

[d533wf]

Firstly I should say that I am very impressed with R-studio. It has done a fantastic job at recovering my 4 disc RAID 5 array (1 disk missing). I have an external RAID controller box but after switching in a new blank disk it will not recognise the disks so I've had to recover it manually.

My question is about recovery time. I have 5.7TB of data which is spread over my 3x3TB working drives. I need to recover all of this data. My drives are connected using SATA-USB cables as I don't have 3 spare internal SATA connections. The RAID block size is 512 bytes.

Currently my files are being recovered at just under 1Mb/s which is going to take a LONG time! Now obviously if this is the only option then I'll just have to wait, but I was just curious as to whether I can improve the speed of this?

Thanks!
Tim

[Alt]

The main bottleneck for R-Studio is the disk access rate of the system. Do you use USB 2 or 3 adapters? And are the disk connected to the same USB port (through a coupler)?
Are you scanning the RAID or copying recovered files?

[d533wf]

USB2 unfortunately (I only have 1 USB3 port) but different ports.

I am copying my recovered files using the 'Recover' tool.

One idea I had was to image the disks first onto my internal hard drives if there is space to increase transfer speed. Is recovering from disk images faster/slower than from (fully working -not failing) hard drives?

Also do you know the typical size reduction for a disk image compared to a physical disk (e.g. how big is a compressed image of a 3Tb hard drive likely to be?)

[Corsari]

Another factor is the average files size
The smallest they are the longer will be the time required to open/close the files in relation to the copy speed.

E.G. We are copying the content of an HP MSA 60 S.A.N. from Genreral Electric Healthcare Systems, composed of 12 drives 1TB each in RAID 6 with 2 missing drives (here it come in the game, partially, the calculation needed for the Q) we have reconstructed past week. Luckily it was filled with "only" 6TB of data, but those medical images are sets made of the image + a small set of description files.

This drops the copy speed to an Average of 4MB/sec

This turns in 330/360 GB/day

Which will end in a copy period time of something less of 20 days

UPS for everything and crossed fingers

[Alt]

USB2 unfortunately (I only have 1 USB3 port) but different ports.

I am copying my recovered files using the 'Recover' tool.

One idea I had was to image the disks first onto my internal hard drives if there is space to increase transfer speed. Is recovering from disk images faster/slower than from (fully working -not failing) hard drives?

Also do you know the typical size reduction for a disk image compared to a physical disk (e.g. how big is a compressed image of a 3Tb hard drive likely to be?)

I think you'd better leave all as it is and let the files be copied.
But if you had created disk images through the USB3 port/adapter, you'd have spent less time. Compression ratio depends on many things, types of files stored on the disk being the main factor. If they are of compressed types, like jpg, the ratio will be small.