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You want an enterprise solution, pay an enterprise price.
what are you going to buy? I thought seagate drives had the same issueno more western digital for me then.
WD deliberately changed TLER support on cheaper models. Now we are forced to buy enterprise class drives (RE2/3/4, yes danman...) for our reliable home raid storage,
what are you going to buy? I thought seagate drives had the same issue
Some drives support spinning at lower speeds rather than spinning all of the way down, and some RAID controllers let them do so for power savings.
The WD GP drives and the adaptec 5-series cards that I know of, and apparently the newer 3-ware cards as well. Most drives other than the green drives are on/off I beleive.
Um, no. Maybe if you try teaching the drive some Scientology. Could work, you never know. Then again, it might start mimicking Tom Cruise, jumping on the couch and screaming...Some drives support spinning at lower speeds rather than spinning all of the way down, and some RAID controllers let them do so for power savings.
For some reason I was thinking you were saying the drive varies its speed.
With Intelligent Power Management, users can minimize power consumption by alternating between 3 modes:
1) Normal operation - full power, full RPM (revolutions per minute)
2) Standby - low power mode spins disks at lower RPM
3) Power-off - disks not spinning
so the WD drives don't have TLER anymore
what about Seagate and Samsung?
looking at this drive for RAID
http://www.newegg.com/Product/Product.aspx?Item=N82E16822152202
Supposedly there is THIS for seagate... But I can't find anyone that can confirm that it works!
I bought a bunch of WD20EADS - WD's Caviar Green 2TB drives at 5400rpm, like a week ago.
I have Adaptec 51645 and 52445 raid controllers, updated with latest firmware (Ver. 5.2.0 Build 17544). I will just refer to one of them only, because both are behaving very similar.
Now my questions are:
- will enabling TLER improve my write performance? My guess is not, but it will prevent drives from dropping out of the Raid array, as far as I understood..
- how can I improve my write performance? Flashing the drives to latest firmwares? Or this is controller's fault?
The first thing you should be worrying about before all else is whether your drives can have their TLER enabled, otherwise the arrays are just a ticking timebomb. As for your performance it sounds like there's some other problems- a 52445 running 4 or 8 drives @ RAID6 should be giving you read/write in the hundreds of MB/s -- like 350+ MEGABYTES per second. As someone already mentioned, make sure write cache is enabled- the default may be "write cache only when protected by battery" but you don't want that.
What are the build dates of your drives? What's the third character in the model number after the dash? (i.e. WD20EADS-00SXXX) If your drive was built before September 30, 2009, and/or the eleventh character of the model number is an "S" rather than a "P", "R" or anything else, then TLER should enable. Lastly, you aren't going to be flashing any drives to any newer firmware unless you work at Western Digital. It's pretty much impossible to get firmware files out of them.
Skeleton linux # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 17182 MB in 2.00 seconds = 8599.49 MB/sec
Timing buffered disk reads: 624 MB in 3.01 seconds = 207.59 MB/sec
Skeleton linux # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 19272 MB in 2.00 seconds = 9646.85 MB/sec
Timing buffered disk reads: 660 MB in 3.01 seconds = 219.30 MB/sec
Skeleton linux # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 18928 MB in 2.00 seconds = 9474.68 MB/sec
Timing buffered disk reads: 684 MB in 3.02 seconds = 226.69 MB/sec
Skeleton linux # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 18474 MB in 2.00 seconds = 9247.24 MB/sec
Timing buffered disk reads: 646 MB in 3.01 seconds = 214.58 MB/sec
Marcus ~ # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 12426 MB in 2.00 seconds = 6217.79 MB/sec
Timing buffered disk reads: 632 MB in 3.01 seconds = 210.12 MB/sec
Marcus ~ # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 12544 MB in 2.00 seconds = 6276.77 MB/sec
Timing buffered disk reads: 628 MB in 3.00 seconds = 209.09 MB/sec
Marcus ~ # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 12664 MB in 2.00 seconds = 6336.68 MB/sec
Timing buffered disk reads: 630 MB in 3.00 seconds = 209.78 MB/sec
Marcus ~ # hdparm -tT /dev/sdc
/dev/sdc:
Timing cached reads: 13322 MB in 2.00 seconds = 6667.06 MB/sec
Timing buffered disk reads: 606 MB in 3.00 seconds = 201.69 MB/sec
Marcus ~ # time sh -c "dd if=/dev/zero of=/mnt/local/Storage/zerofile bs=8k count=1000000 && sync"
1000000+0 records in
1000000+0 records out
8192000000 bytes (8.2 GB) copied, 84.0251 s, 97.5 MB/s
real 1m24.429s
user 0m0.148s
sys 0m9.417s
Marcus ~ # time sh -c "dd if=/dev/zero of=/mnt/local/Storage/zerofile bs=8k count=1000000 && sync"
1000000+0 records in
1000000+0 records out
8192000000 bytes (8.2 GB) copied, 99.7235 s, 82.1 MB/s
real 1m41.415s
user 0m0.156s
sys 0m10.717s
Marcus ~ # time sh -c "dd if=/dev/zero of=/mnt/local/Storage/zerofile bs=8k count=1000000 && sync"
1000000+0 records in
1000000+0 records out
8192000000 bytes (8.2 GB) copied, 95.512 s, 85.8 MB/s
real 1m37.352s
user 0m0.104s
sys 0m10.593s
Skeleton linux # time sh -c "dd if=/dev/zero of=/mnt/local/TEMP/zerofile bs=8k count=100000 && sync"
100000+0 records in
100000+0 records out
819200000 bytes (819 MB) copied, 6.01289 s, 136 MB/s
real 0m6.532s
user 0m0.008s
sys 0m0.992s
Skeleton linux # time sh -c "dd if=/dev/zero of=/mnt/local/TEMP/zerofile bs=8k count=100000 && sync"
100000+0 records in
100000+0 records out
819200000 bytes (819 MB) copied, 5.94442 s, 138 MB/s
real 0m6.428s
user 0m0.004s
sys 0m0.992s
Skeleton linux # time sh -c "dd if=/dev/zero of=/mnt/local/TEMP/zerofile bs=8k count=100000 && sync"
100000+0 records in
100000+0 records out
819200000 bytes (819 MB) copied, 6.50114 s, 126 MB/s
real 0m7.192s
user 0m0.008s
sys 0m1.020s
Marcus ~ # time sh -c "dd if=/dev/zero of=/mnt/local/R5/zerofile bs=8k count=1000000 && sync"
1000000+0 records in
1000000+0 records out
8192000000 bytes (8.2 GB) copied, 41.1173 s, 199 MB/s
real 0m41.645s
user 0m0.104s
sys 0m16.901s
Marcus ~ # hdparm -tT /dev/sdb
/dev/sdb:
Timing cached reads: 14168 MB in 2.00 seconds = 7091.14 MB/sec
Timing buffered disk reads: 624 MB in 3.00 seconds = 207.95 MB/sec
The first thing you should be worrying about before all else is whether your drives can have their TLER enabled, otherwise the arrays are just a ticking timebomb. As for your performance it sounds like there's some other problems- a 52445 running 4 or 8 drives @ RAID6 should be giving you read/write in the hundreds of MB/s -- like 350+ MEGABYTES per second. As someone already mentioned, make sure write cache is enabled- the default may be "write cache only when protected by battery" but you don't want that.
What are the build dates of your drives? What's the third character in the model number after the dash? (i.e. WD20EADS-00SXXX) If your drive was built before September 30, 2009, and/or the eleventh character of the model number is an "S" rather than a "P", "R" or anything else, then TLER should enable. Lastly, you aren't going to be flashing any drives to any newer firmware unless you work at Western Digital. It's pretty much impossible to get firmware files out of them.
Damn, I need to get a job at WD, thenIt's pretty much impossible to get firmware files out of them.
If you're testing with files that are large enough to need to write to multiple drives (depends on your stripe size and, to some extent, the file system's block size) in the array you should be seeing read/write performance much higher than that. The only time I see numbers that low are when I'm writing out files smaller than my stripe size, which is set to 1MB (my array holds mostly video files and linux/windows/game disc iso's so 99% of it is files over 1GB each). I can also copy out of .iso's on the array to folders on the array at 200+MB/s (basically, file duplication) using a 5-disc raid 5