D-Link Forums
The Graveyard - Products No Longer Supported => D-Link Storage => DNS-321 => Topic started by: nrf on December 02, 2009, 11:08:54 AM
-
with the new firmware, it seems many people's wishes have been granted.
it appears that the support for admin is much improved -
can check file system
can use SMART
good coverage on mail alerts and logs
some killer bugs fixed like itunes admin page hangups thus less damage from dead processes
support structure for add-ons
but my question is, bottom line, will the data be reliably stored therein or
do I have to worry about my photos still disappearing? is it good enough to store
a profile you can use from different machines or only for 'dumping' backup copies?
anyone done tests for data integrity?
-
IMO, you should NEVER trust a single device to store your only copy of any important data!
Remember: Data you don't have at least two copies of is data you don't care about.
-
I can't answer your question about testing for data integrity, that would be internal to Dlink. But I can tell you that I very much agree with GRJ on his response to you. For myself, I will never trust a single device to be my sole backup. I work in a data center and even there, with multiple copies and vast RAID arrays, we still keep a copy of everything on either tape or optical platter. At home I have my 321 set to RAID 1, but I also have a different brand of drive, identical size and internal to my desktop PC that does an incremental backup of the NAS box every day while I sleep. And I also do a small FTP backup of critical data to a friend's NAS box about 1200 miles from my home.
If something like the controller board fails in the NAS during a write or a cache dump, chances are that you will lose both drives. The NAS can help when trying to prevent against drive failures, but it can't protect against NAS failures. So if you have something you can't do without or can't stand to lose, do a backup to a separate machine, preferably in a separate province or state.
Just an opinion, from someone who has been in the IT field for well over 20 years now.
Ryder
-
I don't need a tutorial on backup or to be treated like a fool.
I wasn't trying to start a rehash of an old thread. after some amount of time, whatever backups you recyle eventually get re-used. but if in the meantime some of your files got messed up, there is then no backup to go back to. unless you can afford an infinite amount of backup media and the backups never go bad themselves. (it is juggling no matter what you put it on or how many of them you have)
what I found was that after putting my stuff on the box it 'lost' some of the files, which I was eventually able to detect and restore from a backup. but unless there is some detectable event, like a crash or fire or something, I would prefer stuff just 'stay there'.
so how confident can I be that the admin abilities of SMART, SMART tests, and DIsk Scan will be enough to know that things are 'ok' ? Or expressed differently, how does the reliability and maintability of this device compare with a software raid configuration under windows or linux?
nrf
-
I've never had anything just disappear from either the DNS-321 or DNS-323, so I'm not sure what you're experiencing.
-
I don't need a tutorial on backup or to be treated like a fool.
I wasn't trying to start a rehash of an old thread.
I didn't read anything stating you were a fool or needed a tutorial on how to backup. Or rehashing an old thread? Am I missing something here?
To speak to reliability of the NAS, well what Linux should be providing... EXT3 format (released in firmware 1.03) is the most reliable with something called journeling but comes at a performance cost. And you probably already know RAID 1 for hard drive failure protection. Also, disapearing files, well my wife hates her photo taken so those files end up missing all the time, and I use the NAS to hold and share the photos since it's a large amount of files. I always backup my photos and financial data to DVD and maintain a hidden copy from my wife just incase she gets crazy. Files generally don't just disapear, the cause just needs to be found.
Also, I have not heard of people stating data loss since I've been on this forum, albiet not very long, but I would think data loss would be a huge issue and we would see it everywhere.
-Joe
-
will, I asked about the reliability and instead got a lecture about backing up my files...in red no less.
the point is, a year ago I used this box in its original unfit condition, and did in fact lose some files (but had backups once I noticed). things like services hanging etc. may have had something to do with it.
I also notice as I have put my unit back online with the new firmware that ext3 is extremely slow even without raid.
I am optimistic that in a year's time they may have improved things a whole lot. the feature list of the 1.3 firmware is pretty much what anyone would want in a device they used seriously.
I'm going to put it through its paces and use some dircmp's to see if anything is amiss. just wondered if anyone else had done anything beyond relying on the disk scan and smart test capabilities.
between the speed (or lack thereof) and this lurking concern I am still not sure if or how I might use mine.
-
I don't think GRJ was lecturing you. I don't know you nor how experienced you are and he was just giving sound advice, which you aparently already practice.
As for reliability, I personnaly feel it's there but you get what you pay for. This was a very inexpensive NAS and performance is poor. It's very poor if you're sharing it with others. I'm not slamming the product but if you compare it to professional equipment, again, you get what you pay for and for me this was my first baby step into a real NAS. Yes, EXT3 takes 25% or more performance away but to hopefully prevent data corruption I think it's the smarter choice.
Have you tried FreeNAS? I use to run it in a VM and it was great. The only downside it I needed to leave my computer on for others to access the data.
-Joe
-
after the silent corruption incident combined with lack of much performance gain from jumbo packets I put my 321 on the shelf and figured out how to do software raid on my myth box.
now that the firmware is in reasonable shape (possibly fit for use) I am wondering what if any use I might have for it. I just now tried out the multimedia server and found that it sorts the tracks in an album alphabetically by song name rather than by track number. so much for that idea.
in any case I guess everyone is more excited about being able to add functions than just the basics of performance and reliability. at least this time around there are some admin features that seem to address the operations and maintenance angle.
-
will, I asked about the reliability and instead got a lecture about backing up my files...in red no less.
Well, if you read your first post, it sure sounded like that was your only copy. We can only infer what you put in your post here, there is no magic wand we can wave to see if you really mean something besides what you post.
-
curious view on life - believing people say one thing but are thinking another and answering what you guess they really meant.
no straight-shooters left in the world? what happend to straight talk/clear communication?
maybe if I said I didn't have backups, in which case the lesson would have been learned already so another one wouldn't have been adding anything to the story.
I just want to know how stable/reliable the device is, the rest of my storage hierarchy is not part of the discussion.
-
Well, my experience has been very good with both the DNS-321 and DNS-323. I have had the DNS-323 for over a year, and the DNS-321 for about 8 months. Never had any issues of lost data on either of them.
-
thanks. an answer!
how do you make sure your files are good?
also, have you moved to ext3?
nrf
-
Once a month I have a compare run that actually does a binary compare of my backup with my primary file disks, which give me confidence that the files are good.
I have not moved to EXT3, I'm simply too lazy to do the reformat and copy 900gigs of stuff back! :)
-
that's a lot of juggling! can you be more specific? what do you use to do the compare?
enquiring minds want to know!
-
Maybe this kind of information is what you are looking for then.
I have two DNS-321's. I use one as a primary and the other as a secondary. The primary DNS-321 has two 1TB WD drives while the second DNS-321 has two 1.5TB Seagate drives.
I use the secondary DNS-321 to backup the primary DNS-321 as well as all the computers here.
I currently have 1.5TB used on the primary DNS-321.
To backup the data I am using RoboCopy from my VISA Ultimate based system.
REM Backup DNS-321
robocopy \\dlink-59c1b6\Volume_1\Media \\dlink-07195C\Volume_1\Media /MIR /Z /LOG:daily-backup.log /TEE
REM Backup XP system
robocopy "\\HPLAPTOP\C$\Documents and Settings\User\My Documents" "\\dlink-07195C\Volume_1\Backup\Carole\Daily\My Documents" /MIR /FFT /Z /LOG:daily-carole-1.log /TEE
etc...
Robocopy reports 'Mismatch' and 'FAILED' operations. So Robocopy checks to make sure the files copied are not corrupted. If they do not match it will be reported in the log and final report.
For the file missing issue.
When I run Robocopy it reports the number of files and directories added 'copied'. When the backup script is run with no new files added no new files are reported.
I have Robocopy set with the option to remove files that no longer exists on the source. Robocopy will remove any items that no longer exists on the primary. This means if I rename a folder then Robocopy will remove the old folder on the secondary and copy the new files.
Robocopy also reports any such files that are removed in the 'EXTRA' part of the report.
So if I ran Robocopy and no files had been removed from the source I expect the 'EXTRA' field in the report top show a value of zero.
# First run, new files added. Some deletions.
robocopy \\dlink-59c1b6\Volume_1\Media \\dlink-07195C\Volume_1\Media /MIR /Z /LOG:daily-backup.log /TEE
------------------------------------------------------------------------------
Total Copied Skipped Mismatch FAILED Extras
Dirs : 8242 11 8231 0 0 2
Files : 91917 216 91701 0 0 52
Bytes :1438.628 g 30.758 g1407.869 g 0 0 311.58 m
Times : 2:06:35 1:28:06 0:00:00 0:38:28
Speed : 6247519 Bytes/sec.
Speed : 357.485 MegaBytes/min.
Ended : Sun Dec 06 18:33:46 2009
# Second run. No new files.
robocopy \\dlink-59c1b6\Volume_1\Media \\dlink-07195C\Volume_1\Media /MIR /Z /LOG:daily-backup.log /TEE
------------------------------------------------------------------------------
Total Copied Skipped Mismatch FAILED Extras
Dirs : 8242 0 8242 0 0 0
Files : 91917 0 91917 0 0 0
Bytes :1438.628 g 01438.628 g 0 0 0
Times : 0:44:48 0:00:00 0:00:00 0:44:48
Ended : Sun Dec 06 19:36:36 2009
So I have not seen any data loss due to the DNS-321.
I also did not see data loss with the prior releases of firmware.
Since the DNS-321 is Linux based I would expect no less. The disk is handled by the Linux kernel modules which are standard. The RAID, file system support and everything else related to disk usage and access is all handled by standard Linux modules which are extremely solid and field proven for millions of systems in the wild.
-
I use Beyond Compare (http://www.scootersoftware.com/), I've used it since the 1.xx days.
-
thanks for the useful information. I think the problem with the dns earlier related to having services hang because of too many files, not sure. the photo files it lost track of certainly weren't being used by the itunes or media servers, but they disappeared just the same, multiple directories worth.
I'll have to study your examples carefully.
it seems that the adage 'trust but verify' is appropriate here.
I'm also curious if you do any off-site data movement.
-
I'm also curious if you do any off-site data movement.
I'm not quite sure what you mean exactly by this nrf, could you explain what you need to know a bit more in-depth please?
Ryder
-
I'm not asking for more, just saying I have enough to contemplate for a while and I see a serious issue with my own backups whereby I need an off-site mechanism for the worst of disasters.
thanks!
nrf :D
-
I use Mozy on-line backup for critical documents, that's added to my other backup levels.
I'm not sure what DNS issue you're talking about, but my DNS-323 has around 900gigs of data on the RAID-1 array, and over a million files. I don't know of any issues relating to number of files or file sizes.
-
Off-site backups with sensitive data... I would never use a third party server to backup sensitive information unless it was 256bit AES encrypted before it left my computer with a strong key. That's my opinion and anyone can do what they want with thier own data.
nrf, how much data are you talking about, the frequency, and is this personal or company related?
If it's company related and you have another sister locations, make them your site and get the data to them somehow.
If it's personal (home), I think my comment above speaks to it well. I have a Verizon account which gives me lots of storage space. I would encrypt it and upload the data. Or you could backup your data to a USB drive and take it to work and put it in your desk. It's off-site.
Getting back to data reliability, I too can testify that I have been using Acronis to backup my home computers to the NAS and running a verification after the backups are complete which alway have passed. I used EXT3 RAID1 until last week when I made the shift to EXT2 RAID1 to obtain a huge speed boot. My specific use of the NAS is primary backup of my computers. If the NAS becomes corrupt then so long as my computer didn't die at the same time, I'm good. There is always risk, you just need to know what risk is acceptable.
-
Off-site backups with sensitive data... I would never use a third party server to backup sensitive information unless it was 256bit AES encrypted before it left my computer with a strong key. That's my opinion and anyone can do what they want with thier own data.
From the MOZY site.
# 128-bit SSL encryption: The same technology used by banks secures your data during the backup process.
# 448-bit Blowfish encryption: Secures your files while in storage, providing peace of mind that your private data is safe from hackers.
I don't spend any time worrying about the safety of the data there.
-
From the MOZY site.I don't spend any time worrying about the safety of the data there.
Your data is only safe provided there is not an "inside man" at MOZY, or any other site for that fact. A disgruntled employee in the right area could do a lot of damage. That's why I say the data should be encrypted before it's uploaded. OR are you just stating the data you place there is not sensitive so should it be comprimised you have no problem with that? I'm unsure what you meant.
-
Well, in the unlikely event that all of my other backups are compromised, and there is strategically placed disgruntled employee at MOZY, I guess I'm out of luck. OTOH, I probably have a better chance to be hit my lightning. :D Since I have two RAID-1 NAS units with identical contents backed up twice a week, I'll probably never need the MOZY backup. I also have some NDAS drives that get updated every couple of weeks with an archive copy of all the same data.
-
this is turning out to be a great discussion thread.
what I was thinking about in off-site backup is something like
a fire or major lightning strike. Given I have some things that I would
like to still have after something like that... some may be very personal and
others not so much. This is the data equivalent of a safety deposit box, which
I've not ever used. but one can hope to get wiser, right?
I've read of people using gmail as offsite storage, it sounds like one could pack/encrypt and
drop them as attachments.
maybe the safety deposit box could hold some data once in a while.
more to think about.
anyway, thanks for the engaging discussion.
nrf
-
One simple method of off-site storage (most of the time anyway) is to stick a copy in your car. Typically, for most folks, if you're away, so is your car. :)
-
Well, in the unlikely event that all of my other backups are compromised, and there is strategically placed disgruntled employee at MOZY, I guess I'm out of luck.
Lets hope that doesn't happen. My point wasn't data loss at a third party location, but someone using your data. Maybe you store finincial data like Quicken, copies of credit card statements, etc... My point is identity theft. It happened to me when my military records were taken and used by someone else. I never found out who used them but I was able to resolve all the issues that came from it. Now I check my credit report all the time because I never know if this will pop up again. So I could be a little sensitive to offloading data to a place you don't control and why I suggest you encrypt it on your computer before sending it for storage.
In the end, everyone will do what they feel is best for thier needs but I just wanted to shed some light on a potiential issue.
-Joe
-
Obviously, anything's possible. I don't spend too much time worrying about it. I really think there are very few people at any of the on-line firms that have access to the data. If they were having this much trouble with data security, they'd be out of business pretty quickly.
I hasten to add, as far as military records are concerned, there are literally tons of government employees you're trusting with that data, it's a far bigger risk than on-line backup, and you can do absolutely nothing about it. ;)
FWIW, I check my credit report every four months, I do it on a rotating schedule and get my free annual report from each service. Since most of them have very similar data, rotating them gets me quicker looks at potential issues, and I still don't have to pay for the privilege of seeing my report.
-
FWIW, I check my credit report every four months, I do it on a rotating schedule and get my free annual report from each service. Since most of them have very similar data, rotating them gets me quicker looks at potential issues, and I still don't have to pay for the privilege of seeing my report.
I do the same thing.
I think I got us off topic. Hopefully nrf got the info asked.