Hi,

 

I'm running unraid 4.4.2 with a simple 3 disk setup:-

 

Samsung F1 750GB (Parity)

Samsung F1 750GB (disk 1)

Western Digital generic 160GB (disk 2) - came with the HP server

 

All are contacted by SATA.  I noticed that writes to disk 2 were slow - really slow, and this is whether I'm writing over the network, directly from an external USB drive, or from disk - disk.

 

I've tested this by copying a 1.21GB file from a portable USB drive to each of the drives:-

Disk 1 : 58.174sec

Disk 2 : 288.601sec

 

Now even taking in to account, RPM, disk size, number of platters, different manufacturers etc... surely that is too slow!!  I would expect the Samsung F1 to be faster, but not 5x!

 

So any ideas how I can make sure everything is connected/configured ok?  Should I upgrade to unraid 4.5? 

 

I tested the read performance too, disk 2 was actually a couple of secs faster (48.6sec).

 

Many thanks.

 

Matt.

So any ideas how I can make sure everything is connected/configured ok?

The only way anybody can answer that is for you to attach a copy of your syslog to your next post.    Depending on how you have the disk configured, it might be drastically different performance, or it might be experiencing lots of errors, and we have no way of knowing by you just saying it is "slower"  A syslog for analysis is pretty much mandatory to be able to help you figure out what is happening.

Should I upgrade to unraid 4.5?

Actually, you should upgrade to 4.5.1.   Your existing release (4.4.2) is 14 releases old.   Major improvements in write speed have been made (approx 20% increase from various reports)

 I tested the read performance too, disk 2 was actually a couple of secs faster (48.6sec).

A good sign.

 

You can run the hdparm command on each of your disks to learn their basic speed capabilities.  It will vary greatly even when everything is working properly.

 

To run the same command as I did to get the following listing, on your server, type:

hdparm -tT /dev/[hs]d?

 

It will take 5 or 6 seconds per drive to run, longer if it has to spin up the drive first, so be patient if you have a lot of drives.

 

Here is a subset of the result from running that same command on my server 

(Notice the speeds range from 17.08 MB/sec to 100.22 MB/sec. 

Yes, 5x faster is possible with a fast, 7200RPM current drive.):

/dev/hdi:
Timing cached reads:   1210 MB in  2.00 seconds = 604.63 MB/sec
Timing buffered disk reads:  162 MB in  3.01 seconds =  53.81 MB/sec

/dev/hdj:
Timing cached reads:   1116 MB in  2.00 seconds = 557.72 MB/sec
Timing buffered disk reads:   62 MB in  3.09 seconds =  20.07 MB/sec

/dev/hdk:
Timing cached reads:   1336 MB in  2.00 seconds = 668.24 MB/sec
Timing buffered disk reads:  200 MB in  3.02 seconds =  66.22 MB/sec

/dev/hdl:
Timing cached reads:   1334 MB in  2.00 seconds = 666.49 MB/sec
Timing buffered disk reads:  194 MB in  3.04 seconds =  63.81 MB/sec

/dev/sda:
Timing cached reads:   1326 MB in  2.00 seconds = 663.06 MB/sec
Timing buffered disk reads:  242 MB in  3.01 seconds =  80.46 MB/sec

/dev/sdb:
Timing cached reads:   1370 MB in  2.00 seconds = 684.79 MB/sec
Timing buffered disk reads:  208 MB in  3.01 seconds =  69.05 MB/sec

/dev/sdc:
Timing cached reads:   1330 MB in  2.00 seconds = 665.26 MB/sec
Timing buffered disk reads:   52 MB in  3.04 seconds =  [color=blue][b]17.08 MB/sec[/b][/color]

/dev/sdd:
Timing cached reads:   1210 MB in  2.00 seconds = 605.12 MB/sec
Timing buffered disk reads:  156 MB in  3.03 seconds =  51.57 MB/sec

/dev/sde:
Timing cached reads:   1344 MB in  2.00 seconds = 671.82 MB/sec
Timing buffered disk reads:  188 MB in  3.02 seconds =  62.25 MB/sec

/dev/sdf:
Timing cached reads:   1156 MB in  2.00 seconds = 577.75 MB/sec
Timing buffered disk reads:  302 MB in  3.01 seconds = [color=blue][b]100.22 MB/sec[/b][/color]

 

Joe L.

Thanks for the reply, syslog is attached.

 

I wonder if it's something to do with the sata cables/motherboard and how it's all connected.

 

Matt.

syslog-2010-02-11.txt

Thanks for the reply, syslog is attached.

 

I wonder if it's something to do with the sata cables/motherboard and how it's all connected.

 

Matt.

Other than it looks like it is SATA-1 vs. SATA-2, I see nothing in the syslog that indicates errors with the drive.  It is just slower.  Another actor might be how full the file-system is.  If getting full, the reiserfs might be working much harder to fit the file in non-contiguous spaces.