I have just built my first UnRaid box, and very simple it was too. For initial set-up (and thanks to a lack of free hard drives) I am using a 2.4G P4 box, with 1G RAM, and two factory fresh 1.5Tbyte hard drives.

 

The array is now 'parity sync in process' and has taken over 3 hours to progress to 14%. The estimated time left is 1979 minutes - another 32 hours.

 

Firstly these figures seem a little disproportional - if 14% takes 3 hours, I should be done in around 20 surely?

 

Secondly, is this enormous time normal? Presumably every time I add a new (1.5Tbyte) drive I would see the same thing?

 

Lastly, if the array was in use now (it isnt) would it still be usably fast, or would performance be degraded while parity was underway? I guess if the answer is 'not affected' the parity calc would just take longer, possibly running into days or weeks?

 

Am I simply expecting too much from consumer grade hardware?

 

Thanks in advance for any advise, suggestions or anything else.

The estimated time is a weighted average... it will get more accurate as time progresses, but I agree, for two drives it seems slow.

 

On average, a modern disk drive can be written to on its outer cylinders at about 100 MB/s.  On its inner cylinders (which hold less data) it typically drops to 60 - 70 MB/s.

 

Assuming the faster speed, it will take 10 seconds to write 1Gig.  You have 1500Gig to write... that is 15,000 seconds ... if the drive could write that fast, and most cannot.  Figure closer to an average of 80 MB/s is more realistic.  That then equates to 18,750 seconds.

 

15,000 second  =  4.1 hours

18,750 seconds = 5.2 hours

 

Those speeds are only possible if your system bus is able to handle the bandwidth.

 

It appears as if you are being limited by something... is this a PCI bus?  Are you experiencing errors in the syslog?  Did you configure the disks in the BIOS as legacy IDE emulation?    (Were they "hda" and "hdb" ? or "sdX" devices?)

 

You might want to post a system log (syslog) for analysis.  Instructions under troubleshooting in the wiki.

 

Joe L.

Joe,

 

Thanks for the post. Under devices, I have:

 

pci-0000:00:1f.2-scsi-0:0:0:0 host1 (sda) SAMSUNG_HD154UI_S1XWJ1LS907248

pci-0000:00:1f.2-scsi-1:0:0:0 host2 (sdb) SAMSUNG_HD154UI_S1XWJ1LS907263

 

I assume the clue here is the sda abd sdb. The motherboard is a rather old Asrock 945G (http://www.asrock.com/mb/overview.asp?Model=CONROE945G-DVI) using the onboard SATA ports.

 

Should I be stopping the devise, rebooting and changing the hard drive set-ups?

syslog attached - dont see anything obvious, but then I probably wouldn't!

syslog.txt

Jul 26 00:21:24 Tower kernel: ata1: SATA max UDMA/133 cmd 0xd080 ctl 0xd000 bmdma 0xc800 irq 19

Jul 26 00:21:24 Tower kernel: ata2: SATA max UDMA/133 cmd 0xcc00 ctl 0xc880 bmdma 0xc808 irq 19

Jul 26 00:21:24 Tower kernel: ata1.00: ATA-7: SAMSUNG HD154UI, 1AG01118, max UDMA7

Jul 26 00:21:24 Tower kernel: ata1.00: 2930277168 sectors, multi 16: LBA48 NCQ (depth 0/32)

Jul 26 00:21:24 Tower kernel: ata2.00: ATA-7: SAMSUNG HD154UI, 1AG01118, max UDMA7

Jul 26 00:21:24 Tower kernel: ata2.00: 2930277168 sectors, multi 16: LBA48 NCQ (depth 0/32)

Jul 26 00:21:24 Tower kernel: ata1.00: configured for UDMA/133

Jul 26 00:21:24 Tower kernel: ata2.00: configured for UDMA/133

 

Seems to me that the drives are recognized as SATA, yet still running at IDE speeds.  If you have important data on the server, then let the parity sync complete (as slow as it may be), then do the following.  If not, then cancel the parity sync now, reboot, and check your BIOS for any settings related to IDE and SATA.  In general, you'll want to disable anything that says 'IDE' (esp. IDE emulation), and enable anything that says 'SATA' and/or 'AHCI'.

The only options I have under IDE configuration is 'disabled, compatibility or enhanced'. Set to disabled the disks arent seen (either on the BIOS boot or in unRaid itself). I therefore have it enhanced - which is where it was before.

 

Is the simplest route forward here simply to swap the cpu/mb combo for another and see if performance improves? Presumably I can just plug the USB key into a new (USB bootable, hopefully more modern) board and the settings will be taken over as they are on the Flash drive?

 

Thanks again for your help....

What about your SATA BIOS options?  Many motherboards have one called 'IDE Emulation mode' or 'Legacy' or similar.  This will force all your SATA drives to run at IDE speeds.  Again, you want your SATA BIOS settings set to AHCI or SATA Type.

 

If you have some more hardware laying around that you can try, then by all means, try it.  Yes, you can just move the flash drive to another server and it should work just fine (though you may have to change the boot order).  However, if you don't have spare hardware, I would try messing with what you have a bit more before throwing down any money.

There are no SATA BIOS options - just the three settings in my post above. I have confirmed this in both the BIOS manual on the Asrock website, and playing with the machine. I also got a colleague to put some fresh eyes on it, but nothing there. It may simply be that this is a budget board, and thats all you get. I have started a thread in the Hardware section requesting a recommendation for a board - I'm having trouble sourcing the 'standard' Supermicro one here in the UK.

 

Thanks for your reply.

Am I simply expecting too much from consumer grade hardware?

 

You are not expecting too much from consumer grade hardware but rather you are expecting too much from old HW.

 

This is the XOR speed from your CPU.

Jul 26 00:31:50 Tower kernel:    pIII_sse  :  4322.400 MB/sec

Jul 26 00:31:50 Tower kernel: xor: using function: pIII_sse (4322.400 MB/sec)

 

This is the XOR speed from a core-2 dual E7200.

Oct 21 21:02:54 Tower kernel: pIII_sse : 9528.400 MB/sec

Oct 21 21:02:54 Tower kernel: xor: using function: pIII_sse (9528.400 MB/sec)

 

There is no AHCI driver loaded so you are not running at AHCI mode but rather at IDE mode that in theory will be a little bit slower (but i don't think this is a show stopper).

 

 

Thanks GK20 - new hardware on order to see if this improves things on second build, but performance is now speedy enough now that everything is ready!