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Author Topic: NAS (Network-attached storage)  (Read 6306 times)
Ronny Nilsen
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« on: December 28, 2010, 02:09:36 PM »
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I'm considering setting up a NAS to keep all my images (and other files) on in the house for access from all my computers. LR catalog file and previews will continue to live on their dedicated SSD, so I figure that LR and PS will continue to behave reasonably fast  even with the image files on a NAS.

But is this a reasonable assumption?

Some brands and models I'm considering is:
  • Netgear ReadyNAS Ultra 6
  • QNAP TS-659 Pro+ 6-bay Turbo NAS
  • Cisco SB NSS326 Smart Storage 6-bay

Does anybody have any experience with any of those? I think I want a 6-bay, not because I need that much storage (4 bay would be enough) but I want RAID6 to reduce risk and possible downtime. And I don't think of RAID6 as backup, that I will continue to do to separate ans slower medias.  Grin

Basically I want to solve my storage problems for the next 3 years. My current setup is to use eSATA to external enclosures, but those are beginning to get old and show signs of failing, so I'm trying to find a new problem free solution...

Not having to keep my main computer (win7) on to have access to my files is also tempting.

Ronny
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PierreVandevenne
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« Reply #1 on: December 28, 2010, 03:14:50 PM »
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I have a Readynas Pro Business at the office and an Ultra 6 at home. I am generally happy with both.
A few notes
- if you buy the optimal set of drives, you should get a very decent transfer rate. At the house, I recycled a few 1TB drives that I had plus 1 2TB enterprise drive and I have around 70 MB/sec on a cheap Gigabit ethernet. At the office, I have around 90 MB/sec without even looking at optimization: i just filled it with the recommended enterprise class 1TB Seagates. That's significantly slower from our main DL380 G5, but the cost per GB is very significantly lower.
- I've yet to have a drive failure (a bit more than a year on the Pro Business and something like 6 months on the Ultra), but I have extended the storage dynamically and that went really smoothly.
- I initially had issues with the Ultra when I tried a 2TB "long sector" disk that wasn't on the approved list yet. It failed spectacularly (may have been a bad drive too, WD refunded it at once) and I was a bit scared because I had tried a volume extension immediately after installing the drive but the array recovered nicely and was usable at something like 25 MB/sec during the rebuild.
- the recommended drives are "enterprise class". Basically, that means that
   * they aren't supposed to suffer from vibrations generated by the array from either a performance or a reliability point of view.
   * they won't spin down/park/sleep as much as standard end-user drives.
   * they cost about 2.5 times the cost of standard end-user drives.
I am running a mix of enterprise and standard drives at home, with no issue at this point.
- those things are very close to standard PCs running a custom version of Linux. Upgrading memory was easy. I did it just in case, as you can run several servers on the ReadyNas.
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degrub
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« Reply #2 on: December 28, 2010, 03:30:44 PM »
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i have two ReadyNas NV+ for working storage, backup, and media streaming for about 5 years. Make sure the drives are on the hardware compatibility list. And be sure to keep a backup of the NAS (via USB attached drive or another server) in case you lose a NAS motherboard.

Frank
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davidewers
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« Reply #3 on: December 28, 2010, 04:31:12 PM »
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Being in the computer business I am not a fan of these cheap NAS systems. Most of them have way too small power supplies which seem to fail very easy. Considering how cheap older servers can be found at I would build my own using linux as the OS.
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PierreVandevenne
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« Reply #4 on: December 28, 2010, 05:32:51 PM »
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Well, those NAS aren't cheap: a diskless ReadyNas Ultra 6 is around $900, with 6 enterprise disks, the total cost can be well north of $2000. You can buy an brand new entry level server from HP or IBM for around $1000 - they have 350W power supplies. The Ultra 6 has a 300W power supply and uses a dual core atom (as do the other systems the original poster is considering) that has a TDP of 13-15W and adding 10-13W per drive, you stay well under 50% of the rated power.

Old "entry level" servers are just crap. It isn't easy to add six drives to them, hotswap them, and their processors can have a 100+ W TDP by themselves. They are usually noisy, glorified low-end PCs.

Old business level servers are more interesting, with dual power supplies, a couple of Xeons or Opterons 6 to 12 fans, etc... If one can put them in a well insulated basement, why not, but then one will have to fight - depending on how old the hardware is - with either a flavor of SCSI or SAS. SAS is the only realistic choice, at a cost in a range of $0.80 to $2.00 per GB. Enterprise drives such as WD RE-4 or Seagate constellations are at $0.12 to $0.15 per GB. Also, if you want 8TB of storage, you'll need 20 600GB SAS drives and bays....

I have "free" servers in the office, the previous generations, that I could have used. All of them fully ready to go, with Linux, RAID and tweaks. Yet, with the SAS drive price, the noise, the day to day management issues, I so much prefer the NAS that I spent around $4000 in total for the 2 I have.
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Ronny Nilsen
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« Reply #5 on: December 29, 2010, 02:38:43 AM »
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Being in the computer business I am not a fan of these cheap NAS systems. Most of them have way too small power supplies which seem to fail very easy. Considering how cheap older servers can be found at I would build my own using linux as the OS.

I went that route for many years, but gave it up when I started to need more space. Putting to many
disks inside the server just heats them up and they die fast. Ben there done that. I could easily build a
new server from parts around the house, but for almost the same reasons Pierre mentions I have rejected
that solution. Having kids (1 and 6 y) I don't have space for a server room in the house any more.  Undecided

Today I use external enclosures and eSATA for my disk, and they live longer noe, but the enclusures is
noisy, and the main computer have to be powerd on as well for the files to be available.

So basically what I want is something quiet, that's fast, works without me having to tinker with it, and
it's easy to swap disks when they fail.

The ReadyNas Ultra 6 looks like good one, but there are two things I can't find in the specs:
How quiet is it? The other two is rated at about 40db at working load.
Does it support migration to larger drives, eg. swapping out 1T disk with 2T in the future to get more capasity?

Thanks to all for input so far!

Ronny
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PierreVandevenne
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« Reply #6 on: December 29, 2010, 04:27:15 AM »
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Noise: I can't hear it when the PC is working. It is noticeable when there's no other computer in the room but that's about it. I first put it in our computer room (which is a relatively noisy environment, with a couple of "gaming level" PCs for the kids) but have now moved it to my library and it doesn't even bother me to read. It's easy to forget its there and it can of course go into sleep mode when not in use, but I don't even bother. The noise is also really smooth. This is not a forced turbulent air flow.

Extension: I started a burn-in with 4 500GB drives I had in an older, bad, ACER Altos Easystore. Then removed 2 of them to replace them with 1TB (Caviar Green) I had in external enclosures. I then added the unsupported 2TB WD drive that failed after a few ours during the extension. At that point, I was really worried. Took me a couple of days to source a 2TB RE4 which I used to replace the failed drive and it recovered nicely. I have then replaced the remaing 500gb drives. I also have upgraded the firmware 2-3 on each machine times with no issues, run several file serving protocols, an iTunes and a Squeezebox music server. Also I turned on the ReadyDLNA server, simply plugged a network cable in my Samsung TV and all my media content became immediately available.

The concept is a winner for me. I am brand agnostic though and I am sure the Cisco or QNAP appliances offer the same bang for the buck.
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degrub
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« Reply #7 on: December 29, 2010, 09:13:13 AM »
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i have my NV+s behind my LCD panel and i don't notice them when the PC is on (which is on the floor under the table). i would say mine are much less than 40dB. i would ask Netgear directly or post on their forums.

Check out the max capacity listed for the box.

Frank
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Ronny Nilsen
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« Reply #8 on: February 18, 2011, 03:51:29 PM »
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Just a short update to let you know what I ended up with and how thing worked out in case anybody is interested.

I just got the server last week.

I bought a QNAP TS-859 Pro+ 8-bay Turbo NAS. That way I have space to grow for all my files in at least the next 2-3 years by adding more disks. Current configuration is 4 x 2TB disk running in raid 6. Will have to add another disk soon, but that is an easy operation.

I currently use cheap Seagate ST32000542AS 2TB 5900rpm disks. But even with these disk I see sustained 70-80 MB transfer rate of large files to the server. That's on a home 1Gb network. I transfer all my 50.000 images to the server with SyncBack and made the sw check transfer (reading back the file to compare) and only one file was in error of 1TB of data. That error probably was on the read from the local disk as that disk i starting to become old (one of the reasons to get the QNAP).

After one week I'm very happy with the NAS, and since I use SSD localy with LR db and previews, normal image operations in LR is about as fast as before. Read and write of large panoramas is noticeable slower when loading in PS, but not much of a hardship.

The QNAP is very easy to use, with a friendly web GUI to administrate it. No need to tinker with the OS (Linux) unless you want to. Fast, and so far not a singe error or problem. It even have a Squeeze Box Server so I'm playing all my music from it as well.

Ronny
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armand
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« Reply #9 on: February 18, 2011, 07:20:49 PM »
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I went through this for a while and eventually decided to use a server with Windows Home Server. It backs up automatically all the computers in the house (on windows) with the capability of full restore (I did used it once, the easiest is when you want to change the main hard drive) and I also back up on a regular bases all the important data (using Allway Sync 'n' Go on a flash drive) on the shared folder on WHS plus on an external hard drive. This also allows me to have the documents and pictures synchronized on all the computers.
I tried using the server with FreeNAs and while easy to install and use the speed was not that great and WHS allows you to use different hard-drives and replace them with non-identical drives if you want to.

I wouldn't use WHS as the only backup but combined with and 1-2 external HDD (one preferably offsite) it works quite well. As a caveat I already had the computer for the server and I wasn't using it anymore; it's actually a quite powerful dual-core, so it uses more energy than a dedicated NAS. Noise is decent as it doesn't stay next to me.


PS. so far I have around 680 GB that gets synchronized
« Last Edit: February 18, 2011, 07:29:27 PM by armand » Logged
feppe
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« Reply #10 on: February 18, 2011, 08:12:48 PM »
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I'm planning on building an unRAID server mainly for home theater use, but will also store my RAWs there. I've looked at all the options, and the main advantage of unRAID is that it takes any combination of drive sizes and types, and if your controller is hosed the data is not - it doesn't use a hardware controller, and the files are intact and readable on the individual drives unlike with most (all?) traditional RAIDs or Drobo.
« Last Edit: February 18, 2011, 08:18:48 PM by feppe » Logged

PierreVandevenne
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« Reply #11 on: February 21, 2011, 06:57:12 PM »
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I'm planning on building an unRAID server mainly for home theater use, but will also store my RAWs there. I've looked at all the options, and the main advantage of unRAID is that it takes any combination of drive sizes and types, and if your controller is hosed the data is not - it doesn't use a hardware controller, and the files are intact and readable on the individual drives unlike with most (all?) traditional RAIDs or Drobo.

I gave them a try before buying the ReadyNas... As far as combining drive sizes and types, yes to some extent, but with obvious constraints on the parity drive. You may of course use a big and a small drive as data drives, but your parity drive must be as big as the largest data drive. In a three drive system, you can save a bit (if that is the purpose) by reusing a third older drive.

Since there is no controller, I'd have to agree that if you kill your controller, you don't loose data Smiley. In most cases, you don't kill data if you kill your controller with standard raids either. You may run into trouble if you run an obsolete controller, it dies and you can't find a replacement, true. But the data layout isn't that complex: once you have determined the stripe size, it is actually quite hard to lose data (and you can always try to remember the characteristics of the RAID array you created in the first place). If you can mount an unRaid reiserfs drive without help, you can probably also tackle a normal raid recovery.

In terms of performance, I wasn't happy (getting something like 25-30MB/sec). A cache drive improved the overall performance a bit, but that's just a bit safer than a RAID-0 array, and much slower.

Also, I had a look at their new web site and didn't like it. Not only do they obfuscate the issue (objectively, if their product doesn't have the inconvenience of RAIDs, that's simply because it isn't one - it is at most vaguely similar to RAID 4), but they are selling standard drives at the price of enterprise class drives (a multipler of 2 or 2.5). Yes, they have a disclaimer stating that they can't match the prices of the big players.... but a 100% markup on the public prices of those providers?

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feppe
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« Reply #12 on: February 21, 2011, 07:36:46 PM »
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Also, I had a look at their new web site and didn't like it. Not only do they obfuscate the issue (objectively, if their product doesn't have the inconvenience of RAIDs, that's simply because it isn't one - it is at most vaguely similar to RAID 4), but they are selling standard drives at the price of enterprise class drives (a multipler of 2 or 2.5). Yes, they have a disclaimer stating that they can't match the prices of the big players.... but a 100% markup on the public prices of those providers?

Not sure what you mean by obfuscating. They explain their tech quite clearly for those of us who are not techies - I'm sure there are technical papers for those who care.

Drive pricing seems to be SOP in the business - Drobo has similarly outrageous drive prices, haven't looked at others. You can always just buy the software (or Drobo) without the drives. To be fair, an unRAID box requires actual setup and configuration, unlike with a Drobo which is just putting the drives in.
« Last Edit: February 21, 2011, 07:38:26 PM by feppe » Logged

PierreVandevenne
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« Reply #13 on: February 22, 2011, 04:02:47 PM »
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I wouldn't describe you as a non techie - your posts are always very good when it comes to tech.

As far as obfuscation is concerned, I guess that's an opinion and your mileage may vary depending on how familiar one is with RAID internals.

As far as drive prices are concerned, they offer

Western Digital 2TB  WD20EADS SATA2 Power-saving Hard Drive ... $215
Normal price around $99 (http://www.newegg.com/Product/Product.aspx?Item=N82E16822136344)

at almost the price of the equivalent enterprise class hard drive (RE-4 family)
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136365

I agree they aren't alone in this. But anyone sincerely concerned by the safety of their customer's data wouldn't spend time explaining they don't get competitive prices on drives: they would simply recommend more reliable drives.


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feppe
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« Reply #14 on: February 22, 2011, 05:56:53 PM »
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I wouldn't describe you as a non techie - your posts are always very good when it comes to tech.

As far as obfuscation is concerned, I guess that's an opinion and your mileage may vary depending on how familiar one is with RAID internals.

As far as drive prices are concerned, they offer

Western Digital 2TB  WD20EADS SATA2 Power-saving Hard Drive ... $215
Normal price around $99 (http://www.newegg.com/Product/Product.aspx?Item=N82E16822136344)

at almost the price of the equivalent enterprise class hard drive (RE-4 family)
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136365

I agree they aren't alone in this. But anyone sincerely concerned by the safety of their customer's data wouldn't spend time explaining they don't get competitive prices on drives: they would simply recommend more reliable drives.

Good points. While I might play a techie successfully on the internets Smiley, I'm certainly not an IT pro; but if consumer drives are good enough for Google (.pdf), I don't see why we'd need enterprise class drives in a redundant environment.
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armand
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« Reply #15 on: February 22, 2011, 07:28:59 PM »
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I'm planning on building an unRAID server mainly for home theater use, but will also store my RAWs there. I've looked at all the options, and the main advantage of unRAID is that it takes any combination of drive sizes and types, and if your controller is hosed the data is not - it doesn't use a hardware controller, and the files are intact and readable on the individual drives unlike with most (all?) traditional RAIDs or Drobo.
That sounds similar at some extent with how Windows Home Server works without the windows in equation. While it may not be for everyone so far seems stable enough. The advantage is that you don't have to be very technical to use it, you can even buy a server already made (HP and Acer have them) and just install the hard-drives.
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PierreVandevenne
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« Reply #16 on: February 22, 2011, 07:38:59 PM »
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That study is a bit dated and was somewhat controversial when it came out.

Dated: 2005-2006 - PATA and 1st gen SATA drives from 80 to 400 GB were monitored. Server grade SATA drives didn't exist back then and the price differential per GB with flavours of SCSI and SAS drives was huge. Their results were inconsistent with everyone else when it comes to temperature, they didn't look at vibrations, etc...One of their very strong confirmations was the fact that a drive that gets a single scan error is 39 times more likely to fail within 60 days than a clean drive.

Anyway, here's a much better paper (much bigger sample, less uniform use and conditions) - look at table 1 (summary of findings) and especially figure 10 if you don't have time for the full paper.

http://www.cs.wisc.edu/adsl/Publications/latent-sigmetrics07.pdf

Here's a recent tidbit from France, with the 1st year failure rate at the service department of a big e-commerce reseller.

Failure rate in 1st year for 1 To drives

- 5,76% : Hitachi Deskstar 7K1000.B
- 5,20% : Hitachi Deskstar 7K1000.C
- 3,68% : Seagate Barracuda 7200.11
- 3,37% : Samsung SpinPoint F1
- 2,51% : Seagate Barracuda 7200.12
- 2,37% : WD Caviar Green WD10EARS
- 2,10% : Seagate Barracuda LP
- 1,57% : Samsung SpinPoint F3
- 1,55% : WD Caviar Green WD10EADS
- 1,35% : WD Caviar Black WD1001FALS
- 1,24% : Maxtor DiamondMax 23

Failure rate in 1st year for 2 TO drives

- 9,71% : WD Caviar Black WD2001FASS
- 6,87% : Hitachi Deskstar 7K2000
- 4,83% : WD Caviar Green WD20EARS
- 4,35% : Seagate Barracuda LP
- 4,17% : Samsung EcoGreen F3
- 2,90% : WD Caviar Green WD20EADS

It actually correlates well with my experience with flash cards: the latest/highest capacity models always have a much higher failure rate than their lower tech/density siblings. Note: I can't wait to see numbers for the recent hybrid SSD/HD from Seagate.

So basically, the generic advice would be

- never buy the latest generation in storage.
- swap the drive/media as soon as it starts developing an issue. (the problem for a non techie is 1 - to notice the issue 2 - to make the distinction between a hard error and something he simply doesn't understand or did wrongly)
- enterprise HD are significantly more reliable long term than their counterparts (per that study).
- brands are unreliable indicators as a whole. Issues are mostly model dependents.

The EADS drives seem to be currently the best choice in non enterprise drives. They are however rated for 300.000 load cycles compared to 600.000 load cycles for Enterprise drives

Take a look at stats from some of my systems

Modèle:    WDC WD10EACS-00ZJB0
Durée de fonctionnement (heures)   8352
Nombre de cycles de chargement    33537

-> consumer drive: 4 load cycles per hour of operation

Modèle:    WDC WD2003FYYS-02W0B0
Durée de fonctionnement (heures)   808
Nombre de cycles de chargement    288

-> enterprise drive: 0.3 load cycles per hour of operation

If you take the life expectancy at face value on the basis of cycle counts, the difference is 24x

As all studies say, no single predictor is best, still...
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feppe
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« Reply #17 on: February 22, 2011, 07:42:53 PM »
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That sounds similar at some extent with how Windows Home Server works without the windows in equation. While it may not be for everyone so far seems stable enough. The advantage is that you don't have to be very technical to use it, you can even buy a server already made (HP and Acer have them) and just install the hard-drives.

The main reason why WHS is off of my shortlist is that it requires mirroring for redundancy, while unRAID uses a parity drive. IOW, WHS doubles disk requirements where redundancy is required, but unRAID only requires an extra disk equal in size to the largest disk in the array.

WHS has much higher system requirements; I believe the current version requires a 64-bit CPU while unRAID users claim that a single-core ~2GHz CPU is plenty of power. There was also a critical data corruption bug in an earlier version of WHS which took several months to be fixed, which isn't exactly reassuring.
« Last Edit: February 22, 2011, 07:45:51 PM by feppe » Logged

ednazarko
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« Reply #18 on: March 07, 2011, 08:42:25 AM »
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I've had two failures with huge LaCie drives used in Raid 5 mode.  One happened shortly after I'd loaded the disk with my working files, so I didn't lose anything, but the second happened well afterwards, and had been undetected through a couple of my backup cycles.  Lost a lot - not so much files, since I was able to run recovery software and pull almost all of them back, but the amount of time lost to that process was epic.  In both cases LaCie quickly replaced the units, but I no longer have any faith in them since in both cases, the failure wasn't noticeable until I incidentally ran across destroyed files, by which time there were thousands of ruined files.  In both cases they were on eSATA connections - on USB, the drive has been rock solid steady and reliable, but maybe that's because I no longer rely on it other than as a third-tier onsite backup.

I've built out a couple of multi-drive systems since, and have had no issues.  Running in mirroring mode only.  I don't backup any less frequently, and now do random samples of files to check integrity about once a month (before my backup cycle re-cycles.)  I've also got a couple of Western Digital units running as wireless connected backups, and other than some annoying problems when upgrading my router that caused the drives to be invisible to any 64bit OS... that's been fine, but the speeds of the wireless drives make them useful only for smaller backups.

I no longer have any wired network running, so I'm left with eSATA and Firewire 800 for my large capacity storage.
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John.Murray
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« Reply #19 on: March 07, 2011, 10:55:12 AM »
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When considering any RAID solution, one big factor that often gets left out of the equation is the difference between Enterprise vs: Desktop drives.

A desktop drive's firmware will typically go through an extended recovery process if/when a sector read error occurs, this can be up to 30 seconds; making the drive inaccessible to the operationg system during that time.  When such a drive is part of an array, this long "timeout" will result in the entire drive being marked out - resulting in a degraded array.  You might ask, "why not just increase the RAID timing to account for this?" - the short answer is, you can't stretch a simple disk write transaction (including parity in RAID5) over 30 seconds without some form of battery backup at the controller level.  Enterprise class controllers do have battery backup, but for an entirely different reason: queue depth.

Enterprise class drives typically are built to a higher standard, offering lower vibrational rates and a closed loop feedback system compensating for any rotational variances caused by vibration.  You'd expect failure rates to be inherently lower given the tighter spec.....

I personally only mirror (RAID 1), currently using Western Digital RE class drives.  For the brave, there *is* a firmware utility that will change the timing on a desktop class drive available from WD - I've used it, with no adverse results in a RAID environment.
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