WD 2TB EARS http://lime-technology.com/forum/index.phpDrive Read and Write Speed

[BlackCat]

I committed the sin of buying two disks from newegg within a week from each other so both drives have same manufacturing date and site code. Both drives have been successfully precleared twice. The cycle times for 2 preclears on my first disk were 36 hrs and 44-45 hrs. Now my second disk took 24 and 25 hrs for two preclears. I have posted the cycle times below. From all the cycle times I have seen in the preclear results thread my disk1 zeroing time seems excessively slow. The only thing I saw earlier was that this could be affected by other activity on the server, but the only thing running was the preclear.

 

Disk1:

Device Model:     WDC WD20EARS-00MVWB0

Serial Number:    WD-WCAZA0324519

: Firmware Version: 51.0AB51

User Capacity:    2,000,398,934,016 bytes

 

Disk1 1st Pre-Clear Cycle time:

I failed to copy all the system log info but

the cycle time was about 36 hours

 

 

Disk1 2nd Pre-Clear Cycle time:

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 8:20:16 (66 MB/s)

== Last Cycle's Zeroing time   : 21:47:41 (25 MB/s)

== Last Cycle's Post Read Time : 14:39:26 (37 MB/s)

== Last Cycle's Total Time     : 44:48:31

 

 

Disk2:

Device Model:     WDC WD20EARS-00MVWB0

Serial Number:    WD-WCAZA0423649

Firmware Version: 51.0AB51

User Capacity:    2,000,398,934,016 bytes

 

Disk2 1st Pre-Clear Cycle time:

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 7:00:00 (79 MB/s)

== Last Cycle's Zeroing time   : 5:52:08 (94 MB/s)

== Last Cycle's Post Read Time : 12:15:08 (45 MB/s)

== Last Cycle's Total Time     : 25:08:27

==

== Total Elapsed Time 25:08:27

 

 

Disk2 2nd Pre-Clear Cycle time:

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 6:07:27 (90 MB/s)

== Last Cycle's Zeroing time   : 5:43:43 (96 MB/s)

== Last Cycle's Post Read Time : 12:14:26 (45 MB/s)

== Last Cycle's Total Time     : 24:06:45

==

== Total Elapsed Time 24:06:45

 

I know each drive has its own characteristics, but is there something else that could be the cause like a SATA cable or the drive bay port on the backplane? I jumpered both drives. I didn't see a spot for individual ports in the BIOs but I did change the general setting over from IDE to SATA and SATA type to AHCI.

 

Also, when I formatted Disk1 and added it to the pool it only showed 49 reads and 38 writes, but disk 2 shows 33,298,778 reads and 3,830,610. Both show zero errors. Why such a big difference before even copying data over? I'm thinking disk 1 didn't format properly. However, I was able to transfer a movie file (through shares in my network places) onto disk1 (the slow drive), that took about 2.5 hours for 8GB. I also transfer the same file to disk2 and that only took about a hour. Do I need the bwm-ng package to determine the actual disk performance for reading and writing data? Should I just change my sata cable and run preclear again and depending on the results switch Hot-Swap Bays? I don't have the full syslogs from my Disk 1 preclears because I only copied the SMART data and even screwed that up on the first preclear. The SMART data from both drives showed that they were fine.

 

My Hardware:

CPU: Core i3-540

Motherboard:SUPERMICRO MBD-X8SIL-F-O

HotSwap Bay:SuperMicro CSE-M35T-1B with locking sata cables from monoprice

PSU: Corsair HX650

 

I have attached a picture of web gui showing reads and write prior to any data transfer, a HD_Parm for disk 1 prior to data transfer, SMART data from the 2nd preclear of disk 1, and my syslog which should include the second pre-clear of disk two all the way through transferring the files.

 

Thanks for any insight

 

EDIT:

My network speed is 100Mb/s, verified with ethtool eth0 and data was transferred through wireless G-band...I am also having issues with the server showing in My Network Places, however it shows up fine under "The Internet" on my girlfriends laptop. Don't know if this is info needed for transfer speeds across the network, I figured I would post this in a separate thread.

 

 

 

HDparm_Disk1-12-12-2010.txt

Syslog-Disk1_2nd_Preclear-12-09-2010.txt

Syslog_After_Preclear_Add_Format_Transfer-12-13-2010.txt

[queeg]

I precleared 5 Seagate 2TB LP drives recently and I was seeing about 30 hours each.

[BlackCat]

I precleared 5 Seagate 2TB LP drives recently and I was seeing about 30 hours each.

 

queeg, thanks for the info. I'm just curious why the time would go from 36 to 44-45 hours with no activity on the server, except the preclear. Especially when compared with the other EARS disk. Also, it seems weird that disk 1 didn't really show any read writes after formatting, but disk2 did. Could this be due to less errors(within acceptable ranges, and no reallocated or pending sectors) reported on disk1?

[Kryspy]

I may be guessing here but the Seagate LP drives are 5900 RPM and the Western Digital are 5400 RPM.

 

Kryspy

[kaiguy]

The majority of my drives are WD20EARS drives.  The fastest I've done a preclear on it was about 26 hours (before I ever added a disk to the array).  The slowest was over 30 hours.  It seems to me that as I add more disks, the preclear time goes up.  Also, when I've precleared two or more drives of the same size at the same time, they usually finish right around each other.  My most recent preclears had one end hours after the other (and the late one I started first).  So I think it can just vary for a variety of reasons.

[Rajahal]

I agree.  With the times you are reporting, I don't think you have anything to worry about.  I've found 36 hours to be about average for 2 TB WD EARS, but there can be many factors that affect that.  As long as both drives passed preclear without any worrying SMART reports, you should be fine.

[BlackCat]

Thanks everyone for your input. I decided to switch the drives around between the two bays, just to see if there were any differences.

 

Disk1 in Bay 2

== Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 7:42:47 (72 MB/s)

== Last Cycle's Zeroing time  : 6:24:34 (86 MB/s)

== Last Cycle's Post Read Time : 13:27:52 (41 MB/s)

== Last Cycle's Total Time    : 27:36:22

 

Disk2 in Bay 1

Using :Read block size = 8225280 Bytes

== Last Cycle's Pre Read Time  : 6:51:11 (81 MB/s)

== Last Cycle's Zeroing time  : 5:43:45 (96 MB/s)

== Last Cycle's Post Read Time : 12:14:55 (45 MB/s)

== Last Cycle's Total Time    : 24:50:59

 

Disk 2 was essentially the same in both bays. The zeroing time of the Disk1 definitely improved. Obviously, this shows my hardware is fine and the hard-drive was just running slower when zeroing those first few times for some reason. I just thought I would post the results to give some closure. Thanks again for all the help

[kizer]

Yep both of my WD 2TB EARS took 36-37hours

 

I'm just assuming thats going to be the norm with my build in my signature.