Promise Smartstore DS4600 4X2TB-RAID 5

Skyclad

New member
Hi there,
I do not know if you guys have had this problem, but it is the second NAS with the Virtual Array rebuilt by UFS that the copy operation on destination drive is terribly slow (about 460GB in 24 hours).

These the parameters: parity rotation (left asynchronous), stripe (1 sector). I have used a place holder as one drive was dead. File system is Hfs+.
I think it's a problem with stripe and UFS. I have to copy about 6TB of data, and with this transfer it “takes a lifetime”.

My workstation consist of a Mainboard Supermicro X10SAT, and a controller LSI (Avago) 9300-8I. I must say also that most of the files are 4K big movies.

I'm thinking about a solution but the customer is already complaining about the long time.

Thanks for any hint
 

Skyclad

New member
As I suspected ....the slowness of the copy is due to SW recalculating too small parity stripes (512Bytes).
I copied the same files (4K) from an external hdd to another connected to the controller, and the copy was fast.

Maybe this can be useful to someone.
 

Jared

Administrator
Staff member
One sector stripe size is always slow. I'm actually surprised it copied 460Gb in 24 hours. I've seen some single sector stripe arrays take three to four days to copy out the files.
 
Skyclad":3txeq3f0 said:
Hi there,
I do not know if you guys have had this problem, but it is the second NAS with the Virtual Array rebuilt by UFS that the copy operation on destination drive is terribly slow (about 460GB in 24 hours).

These the parameters: parity rotation (left asynchronous), stripe (1 sector). I have used a place holder as one drive was dead. File system is Hfs+.
I think it's a problem with stripe and UFS. I have to copy about 6TB of data, and with this transfer it “takes a lifetime”.

My workstation consist of a Mainboard Supermicro X10SAT, and a controller LSI (Avago) 9300-8I. I must say also that most of the files are 4K big movies.

I'm thinking about a solution but the customer is already complaining about the long time.

Thanks for any hint


Well,
This is what i do "I call the customer who is having no time and make him sit infront of the computer thats actually doing the job".After 30 minutes to an hour they go back and never call until task is finished :mrgreen:
 
Amarbir[CDR-Labs said:
":1ztmlmic][post]6092[/post] This is what i do "I call the customer who is having no time and make him sit infront of the computer thats actually doing the job".After 30 minutes to an hour they go back and never call until task is finished
haha an effective mekanism :lol:
 

Jared

Administrator
Staff member
Somehow though the hardware is able to do this full speed, probably because it's a simple solid state relay just flipping a switch every 512 bytes. It's software which takes forever to do this due to the fact that it's likely making a separate ATA request for each individual sector now instead of reading in blocks. Eventually, one of the programs (hopefully R-Studio) will wise up and add in a RAM drive buffer to work from so it's prebuffering the sectors and destriping just from RAM.
 

Skyclad

New member
Jared":13i5sl53 said:
[post]6109[/post] Somehow though the hardware is able to do this full speed, probably because it's a simple solid state relay just flipping a switch every 512 bytes. It's software which takes forever to do this due to the fact that it's likely making a separate ATA request for each individual sector now instead of reading in blocks. Eventually, one of the programs (hopefully R-Studio) will wise up and add in a RAM drive buffer to work from so it's prebuffering the sectors and destriping just from RAM.
Detailed and technical explanation Jared. In any case, a high-performance system affects, especially the destination unit. I find UFS very valuable especially with particular file system which R-Studio is still lacking.

lcoughey":13i5sl53 said:
Kind of ironic, isn't it. Smartstore isn't very smart, using 1 sector block sizes.

Right Luke :)
 
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