New Home media / File server build

[Thorin]

Slow ass transfer under way, not that I have much options because the old unit is so slow.

Did you do your benchmarking?  Is it fast, or fast! ?

[Lazybones]

Didn't do an internal drive to drive test but my over the network write speed was 90-99MB/s and reads where topping out at 110MB/s bytes not bits so as far as gigabit file serving goes it is performing very well.

I will do some internal tests to the SSD and back later.

My old unit tops out at 30MB/s over the network and I have 1.5-2TB of data to get transferred so I have started that and it is going to just have to run a long time.

[Thorin]

That sounds pretty damn fast.  90MB/s for 2TB (2,048GB, 2,097,152MB) means 23,301 seconds, or about 388 minutes, or about 6.5 hours.  The old unit is limited to one-third of that, so 19.5 hours.  Yikes.  My Drobo's slow like that, I think it runs maybe 20-22MB/s.  But it sure is easy to set up and add drives to without having to rebuild arrays or anything.

[Tom]

Just make sure you build your array large enough initially so you won't have to extend it for a year or three. my new nas is over twice the size of my old data share, and I have 5TB or more free. And I don't think I'll fill it up any time soon.

By the time I do need to expand it. I'll probably replace all of the drives outright with 3 or 4TB (or larger) disks. So a little rebuilding won't bug me much

(the system fits 7 3.5" HDDs).

[Lazybones]

Just make sure you build your array large enough initially so you won't have to extend it for a year or three. my new nas is over twice the size of my old data share, and I have 5TB or more free. And I don't think I'll fill it up any time soon.

By the time I do need to expand it. I'll probably replace all of the drives outright with 3 or 4TB (or larger) disks. So a little rebuilding won't bug me much

(the system fits 7 3.5" HDDs).

Old capacity was 2TB new capacity is 6TB, the three fold increase should last a while... Also I almost went with 4TB drives as they where on sale for the same cost per TB but that would have driven system costs up even more.

[Tom]

Just make sure you build your array large enough initially so you won't have to extend it for a year or three. my new nas is over twice the size of my old data share, and I have 5TB or more free. And I don't think I'll fill it up any time soon.

By the time I do need to expand it. I'll probably replace all of the drives outright with 3 or 4TB (or larger) disks. So a little rebuilding won't bug me much

(the system fits 7 3.5" HDDs).

Old capacity was 2TB new capacity is 6TB, the three fold increase should last a while... Also I almost went with 4TB drives as they where on sale for the same cost per TB but that would have driven system costs up even more.

Thats why I went with 2TB disks for my nas. Also I had a few because I'd been stockpiling them when ever a really good sale was on. I also have 3 3TB disks just sitting around. I'll eventually add them to my old array and turn it into the backup for the new one. at some point.

[Lazybones]

Data transferred, share links updated. VMs converted to KVM.

Only issue so far is that the easiest KVM tool Virt-Manager only runs under Linux.  Investigating various web UI options for remote management.

FYI converting VMs the simplest solution turned to be booting from CloneZilla saving to a share then booting a new empty VM and restoring. Under Linux CloneZilla updated all of the IDE boot devices to virtual devices.

Much better than attempting direct image conversion followed by manual edit.

Finished the switch late last night haven't done any speed or other tests yet.

[Lazybones]

Performance of the software raid
/dev/md0:
Timing cached reads:   25406 MB in  2.00 seconds = 12717.42 MB/sec
Timing buffered disk reads: 432 MB in  3.00 seconds = 143.88 MB/sec

http://www.storagereview.com/seagate_barracuda_3tb_review_1tb_platters_st3000dm001
Average read - 156 MB/s
Max read - 210 MB/s

So the software RAID is performing just under average for this model of drive..




Performance of the SSD
/dev/sda:
Timing cached reads:   25928 MB in  2.00 seconds = 12979.79 MB/sec
Timing buffered disk reads: 1164 MB in  3.00 seconds = 387.93 MB/sec

http://www.anandtech.com/show/5710/the-adata-xpg-sx900-128gb-review-maximizing-sandforce-capacity/2

I seem to be better or on the money for the SSD performance.


An RSYNC copy from the RAID to the SSD was only about 99MB/s but that isn't a very optimal test.

[Tom]

Increase the stripe cache, that may help your streaming speeds. That is quite low for what you have... You have three 3 TB drives in raid 5?

I'd kind of expect 150% of a single drive's speed with that array. But there are lots of tweaks you can make to improve things. Take a look at that scrip I posted earlier. Its an init.d script.

As for rsync speeds, that's pretty decent. rsync has lot of overhead.

I can setup my 3tb drives as a test to compare if you want.

[Lazybones]

Ya I haven't done any optimization, data is all transferred now so I plan on only doing some minor tweaks.

[Thorin]

Sorry, what's the point of the timing of the cached read?  It doesn't actually show how fast the drive is getting accessed, does it?

Nice access speeds, though, especially compared to my (what, now six year old?) machines sitting at home.

[Tom]

Sorry, what's the point of the timing of the cached read?  It doesn't actually show how fast the drive is getting accessed, does it?

Nice access speeds, though, especially compared to my (what, now six year old?) machines sitting at home.

Cached read is the speed of the interface. Usually it tops off at the speed of the sata bus, but it looks like its reading out of memory for his setup.

For instance, here's my newer raid array:

/dev/md0:
Timing cached reads:   12232 MB in  2.00 seconds = 6119.60 MB/sec
Timing buffered disk reads: 2190 MB in  3.00 seconds = 729.94 MB/sec

As a comparison to Lazy's SSD here's my two fast ones:

ADATA SX900 256GB in laptop

/dev/sda:
Timing cached reads:   22814 MB in  2.00 seconds = 11420.22 MB/sec
Timing buffered disk reads: 1186 MB in  3.00 seconds = 395.08 MB/sec

Kingston HyperX 3K 240GB in desktop:

/dev/sda:
Timing cached reads:   9480 MB in  2.00 seconds = 4743.41 MB/sec
Timing buffered disk reads: 1388 MB in  3.00 seconds = 462.16 MB/sec

[Lazybones]

Damit, I knew I should not have bench-marked it...

Now I will likely find the speed issue is due to my block size or something and can't change that.

[Tom]

Damit, I knew I should not have bench-marked it...

Now I will likely find the speed issue is due to my block size or something and can't change that.

Nah, I think the default stripe unit size is fine for a NAS. They upped it significantly a few revisions (of mdadm) back. It's 512K now I think, rather than the old default of 64K which is great for random access, but horrible for contiguous streaming.

root@mrbig:~# mdadm -D /dev/md0 | grep "Chunk Size"
     Chunk Size : 512K

Your's should be the same.

Also I think it might be possible to change it on the fly with a reshape command.

[Thorin]

Damit, I knew I should not have bench-marked it...

Now I will likely find the speed issue is due to my block size or something and can't change that.

Ignorance is bliss, and all that, eh?