Couple of off performance issues - NV+ <> Mac OSX

[murph7355]

Hi

I'm using a couple of ReadyNAS devices for media streaming. One's an NV with Seagate drives, the other an NV+ with Samsung drives.

A Mac Mini connects to them via WiFi (n), the ReadyNAS units connected to the wired part of the network using gigabit ethernet. So far so good.

The NV works perfectly and exhibits neither of the following issues. I'm at a loss to know why the NV+ isn't working properly!?

1) If I have to restart the network, or the Mac Mini, only the NV is automatically reconnected to the Mac Mini.

The relevant data share for each ReadyNAS is set up as a login item on the Mac Mini. If I click the NV's share finder displays the contents straight away. On the NV+, it takes an age to display, behaving like it's first trying to connect.

This wouldn't be a major issue, BUT I'm using FrontRow as my media interface. Unless I go into Finder after a restart, FrontRow only sees the data on the NV share and not the NV+ share.

Also, I think this issue is linked to the next problem.

2) Playback from the NV+ is extremely jittery to the point that it's unusable. Items on the NV play perfectly, but items on the NV+ don't.

The general software configurations of both are identical. Same firmware versions, the settings in the various tabs etc etc.

I'm going to try swapping ports on the network switch over, but I seriously do not think that's the issue - the network section shows both connecting at gigabit speeds.

Am also considering renaming the volumes on one device - both devices use the same volume names ("data" etc). Again though, I can't see that being the issue as machines connecting will use the fully qualified name (including device name)??

The only other thing I can think of is that perhaps the Samsung disks in the NV+ aren't as performant as the NV. But I wouldn't have thought disk speed would be the limiting factor, and it doesn't really explain problem (1).

Anyone got any ideas?

Thanks in advance
Andy

[murph7355]

Bit more testing done.

Have reinstalled the firm ware. Restarted the unit. Performed volume scans and checked disk quotas etc. No issues flagged, no issues in the health logs etc.

It's definitely not the switch port - swapped those over and the same thing happens.

It's definitely not the network cable - swapped those over and the same things happens.

The drives are, in theory at least the equal of the Seagates in the other device.

Scratching my head on this.

[murph7355]

And a couple more bits...

Per the "optimising performance" links... on this site.

Have tried disabling journalling - no difference (didn't think there would be as the other ReadyNAS does not have this checked).

Have also tried disabling the USB UPS monitor that I noticed was installed on this ReadyNAS. No difference.

Rebooted the device before retesting.

Have just copied a movie from the NV+ to the NV (7.15Gb took 1'28" though that's not really useful ) and it runs fine on the NV. So there's definitely something a miss with the NV+.

[StephenB]

Did you check the network stats?

[murph7355]

Figures below...numbers in brackets are the same figures for the device that's working fine (the NV)

Auto-negotiation 0 (3)
Bad packets 161 (27204)
Disconnect 0 (3)
False carrier 557 (2879648)
Idle errors 17615 (77305269)
Link failures 0 (0)
Receive errors 0 (7)
Symbol errors 106 (979128)
VLAN tags 0 (0)
TCP Retransmits 9144 (34005)
Unrecovered TCP Retransmits 14 (276)

I haven't manually reset the error counts on the NV+ but am not sure if they get reset after a restart or reinstalling the firmware. If they do, the figures probably aren't comparable. Either way, I don't think there's anything major to worry about? (I did take a look at the error stats earlier in the day before I started trying to find the problem and they didn't look markedly different on either unit).

Files are not regularly written to/deleted from either unit. They're used as media servers - I backup my DVDs to the NAS units and serve them to rooms round the house. Ditto music. The NV+ gets a directory of photos copied to it using RSync each evening (early hours of the morning so the traffic from that isn't interfering).

[murph7355]

A few updates....I decided to buy a third NAS unit to allow me to transfer data off the dubious one and fault find without too much risk. You can never have too much storage and there were offers on the NV+, plus I had a couple of spare 500Gb drives (the result of a couple of Seagates going faulty). So the cost wasn't a major issue.

It arrived on Friday. Transfer speeds are very slow - am using a gigiabit attached intermediary Mac. I guess what I should have done is set up an rsync job between the two units, but wasn't thinking too much when I started

Anyway...today I received a bunch of errors on the NAS that's on the go slow!! So it looks like getting the hell out of dodge was a good move! Errors as below:

Sun Apr 8 14:11:43 WEST 2012:
Access to the disk on channel (??) is producing I/O errors. Although the array is still redundant, please replace this drive as soon as possible, as it is likely to fail soon.

Sun Apr 8 14:11:43 WEST 2012:
Access to the disk on channel (??) is producing I/O errors. Although the array is still redundant, please replace this drive as soon as possible, as it is likely to fail soon.

Sun Apr 8 14:11:43 WEST 2012:
Access to the disk on channel (??) is producing I/O errors. Although the array is still redundant, please replace this drive as soon as possible, as it is likely to fail soon.

(there are 3 separate log entries for the above - simultaneous issues??)

Sun Apr 8 14:13:07 WEST 2012:
A SATA reset has been performed on one or more of your disks that may have affected the RAID parity integrity. It is recommended that you perform a RAID volume resync from the RAID Settings tab ( accessible in the Volumes page => Volume tab in FrontView ). The resync process will run in the background, and you can continue to use the ReadyNAS in the meantime.


I'm going to resync it, but am not sure which of the disks is causing the problem. I guess it could be up to three of them...but it seems a bit odd that I'm getting these simultaneously.

Is there anyway I can check the backplane of the NAS for faults? Are there any other things that could cause this sort of issue?

Help appreciated as always.

[murph7355]

Quick info on the disks...they're 4x Samsung 1Tb disks (the other NAS' have Seagate Barracudas (7200rpm).

SMART+ as below (all 4 are showing broadly the same figures).

Model: SAMSUNG HD103UJ
Serial: S13PJ1MQ722244
Firmware: 1AA01113

SMART Attribute

Raw Read Error Rate 0
Spin Up Time 10080
Start Stop Count 17
Reallocated Sector Count 0
Seek Error Rate 0
Seek Time Performance 0
Power On Hours 30018
Spin Retry Count 0
Calibration Retry Count 0
Power Cycle Count 17
Read Soft Error Rate 0
Temperature Celsius 43
Hardware ECC Recovered 80058500
Reallocated Event Count 0
Current Pending Sector 0
Offline Uncorrectable 0
UDMA CRC Error Count 0
Multi Zone Error Rate 0
Soft Read Error Rate 0

ATA Error Count 0

Extended Attribute

Hot-add events 0
Hot-remove events 0
Lp stat events 0
Power glitches 0
Hard disk resets 13
Retries 0
Repaired sectors 0


From a bit of Googling I don't think any of those are problematic? I've replaced Seagates before due to reallocated sector counts increasing, but these figures look OK to me (just not sure what the ECC errors are).

[StephenB]

Not sure about the hard disk resets; the other numbers look fine.

[murph7355]

Not sure about the hard disk resets; the other numbers look fine.

Thanks Stephen. That was my thought too. Plus, I can't imagine multiple disks would fail at the same time (assuming they have).

[murph7355]

Another, hopefully final, update!

Could not fathom what was wrong but the new NAS and the original NV were working fine so it wasn't a big issue.

We then had a storm and a power cut, after which the 2 functioning NAS' were exhibiting the same issue. Arrrrrrggggh.

I then happened to notice that one of the ports on my gigabit switch was flicking between orange (100mbps) and green (gigabit).

So I swapped it out, and guess what. Not only did the two return to fully functioning status, but when I tried the original NV+ it worked again!

Everything previously was showing perfectly OK. Green lights all round, all network connections showing 1000mbps. And the problem followed (or seemed to follow) the original NV+. I can only assume this was pure fluke, and that the intermittent nature of the fault on the switch meant I missed it (either that, or I'm just dumb!).

Anyway, problem solved (fingers crossed).