Trouble copying large files to NAS – very slow, and often fails
Hi all,
I'm not an IT expert sadly, but am nevertheless lumbered with trying to manage our small company's half a dozen PCs networked over wired and wireless LAN. A couple of weeks ago one of them (the newest one, less than two weeks out of warranty!) had a massive hard disk failure and all data was lost. Which was not a good time to discover that backing up had been overlooked slightly (my bad!) and the most recent copy was 10 weeks old. Not only that, but it was only of the My Documents folder structure and did NOT include things like local e-mail content, web favourites, etc. Having spent two weeks sorting things out and rebuilding the system I've learned my lesson, and will now take regular (weekly or so?) backups not just of the Documents but of the entire Windows installations. Which seems to be easier said than done, as it means dealing with large (10-50GB) files...
Basically, I'm trying to copy a ca. 20GB backup file from a WinXP machine to a newly acquired NAS (500GB SATA disk, formatted NTFS) over Ethernet. In between sits a Linksys WAG54GS router/gateway/WLAN access point, with both the PC and the NAS connected via cable (so wireless connectivitiy isn't the problem here).
The trouble is, I've tried several times now and every time the process stops at exactly 4GB. First time this happened, I didn't realise the NAS disk had been formatted by the manufacturer to FAT which has a 4GB file size limit (or so I'm told); but even after reformatting it as NTFS as per manufacturer's instructions the same problem still occurs. If anything it's gotten worse: with the original setup it took 'only' 3-4 hrs to copy the 4GB before it failed, but now it's taking somewhere in the region of 8 hrs or more to do the same!
Small files copy across in a flash, and even large (several GB) sets comprised of multiple files go through fine.
The NAS is available as a Samba share (which is what I'm using); other options include FTP and NFS, although I haven't tried these. It also operates as a local USB drive, but this isn't an option here because I'm trying to set up a network-based backup facility which would be accessible by all our half a dozen PCs, so that I could also automate the backing up via some sort of process scheduling.
I don't know whether it's the router or the NAS or the hard disk which is the problem, both in terms of the slowness of the process as well as the cause of the overall failure. If it's a case of adjusting the router's settings I may be able to do this (although my understanding of networking issues is shaky at best!), or if it's a case of returning the NAS to the vendor as faulty then I'm still able to do that, although probably not for much longer. The trouble is, if I ask Linksys they'll no doubt say it's the NAS, and vice versa (unless they both turn around and blame Microsoft!).
Any help would be greatly appreciated. Thanks in advance!
Software/Hardware used:
Software/Hardware used:
ASKED:
May 20, 2008 3:37 PM
UPDATED:
February 3, 2009 3:01 PM
Answer Wiki:
I would be tempted to get your users to use the backup device to store their data on rather than their local hard drive, although really its still not very resilient in terms of backing up data. You could schedule an NTbackup job on each pc to take copies of the documents and settings folder on each pc (which includes the my documents folders, favourites and most other user specific settings). This would minimise the amount of data passed down to the NAS box.
Think for example what would happen if a flood/power spike took out all the electrical equipment in the building. Most small businesses with that level of data resiliency would go under purely for the fact they had lost all their data and had no way of retrieving it. I understand that small businesses may not be able to afford an expensive solution but just a bog standard server with tape drive should be sufficient in this context, then you can keep your tape off site.(put it this way, the business cant afford a backup solution but can they afford to be without a backup!)
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dear Roope ,
i know of your situation - i’ve had it before.
the problem lies within your linksys.
take a crossover cable or a USB cable and connect the computer directly to the NAS device and try copying again.
it will work perfectly i assure you.
jubai05
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Hello Roope,
whenever I copy large volumes of data I always prefer using Robocopy and this never failed even through WAN links, also it has several switches that allows you to retry and so on.
Please let me know if this solve your issue.
Oopsie I forgot to suggest a troubleshooting checklist!
In order to verify where the problem is you can try and first check if this errors happens also when using USB connection or FTP upload (don’t forget to disable any “timeout” feature on the FTP server.
Anyway shortly:
1st try: connect the NAS via USB (so you eliminate the doubt of faulting network device) and try;
2nd try: remove any wireless connection in the middle and try again
3rd try: backup your router’s configuration and restore it to its default and try
4th try: upgrade your router’s firmware and try again
At the moment I don’t have additional ideas to provide anyway let me know.
Bye
I would take a look at the link utilization and if there are any packet retransmissions or if the packets are getting fragmented. This would be seen more in the larger file transfers as you mention. Wireshark is a good tool for looking at packet captures between the devices. Be sure to use a hub between the client and/or NAS box for placing your network analysis device. Wireshark can do SMB transaction analysis and tell you what is happening on the wire.
Another thing to check for is SMB signing. Any encryption or signing on the link will slow things down. If going across wireless, there could be interference or contention for the airspace.
dear Roope ,
i know of your situation – i’ve had it before.
the problem lies within your linksys.
take a crossover cable or a USB cable and connect the computer directly to the NAS device and try copying again.
it will work perfectly i assure you.