OT: Tips for good hard drives for a home server

OT: Tips for good hard drives for a home server

[Henry, Andrew]

I know this is not md related at all, but this list is read by many that are very familiar with hard drive technology, so it's probably the best place to ask...hope you all don't mind...

I've been using an old laptop as a server with external USB Western Digital MyBooks as my file system: RAID-0 on 2 500GB MyBooks.  I've had quite a few problems with them and one person on this list even suggested simply getting rid of them as they are really cr*p according to his personal experience.  They are, so I am.  Running a 'server' on a laptop turned out to not be the great idea I thought it was (although inbuilt monitor/keyboard and 'ups' as well as small footprint/less heat was a definite plus)

So I'm building a new tower server now as my home server and don't want to make another poor purchasing decision.  The problem is that most HDD manufacturers do not specify spindle count and concurrent transactions/iops on their data sheets.

So if I was in the market for a 'standard' desktop internal 3.5" SATA disc, which is the 'best' option?  I'm looking for 500GB in RAID-0 with possibility of adding another 500GB array at a later date for RAID 0+1.

The price of ultra-performance desktop drives is a bit too steep for my tastes, so WD Velociraptor or Hitachi UltraStars are not really what I am after, unless of course there are no other options in terms of performance in the standard desktop market.

Any tips appreciated.

 --andrew

Re: OT: Tips for good hard drives for a home server

[Ryan Wagoner]

I used to buy Seagate drives for their 5 year warranty. However with
the capacities increasing like they are the 5 vs 3 years doesn't
really matter as much. Out of the 4 Seagate drives (2 160GB and 2
320GB) in my server that are 2.5 years old, the one is already showing
13 reallocated sectors. This might be due to non Barracuda drives
being certified for only 8 hours a day.

Recently I added have 5 Hitachi Deskstar TB drives in two different
machines which have been working great with mdadm in RAID 1 and 5. I
actually bought these after using 6 Hitachi Ultrastar TB drives in my
work's new Dell 2950 server. The server is setup in a 2 drive RAID 1
and a 4 drive RAID 5 for data archival and has worked flawlessly.

The Hitachi's are in the same price range as the Seagate Barracuda's
and offer 24/7 runtime and a 1 in 10^15 error rate vs 10^14 for
Seagate.

Any reason you are using RAID 0 for your server? Normally when I think
of a server reliability comes to mind and RAID 0 doesn't offer any.
I'm assumming you make nightly or weekly backups?

Ryan

On Wed, Nov 12, 2008 at 8:12 AM, Henry, Andrew <andrew.henry@logica.com> wrote:
>

Re: OT: Tips for good hard drives for a home server

[Billy Crook]

Someone just shared this with me and I thought this might be relevant:
http://techreport.com/discussions.x/15863

If it's a home server, a little hassle might not be the end of the
world.  Personally I always try to buy the largest available drives
for mass storage, so I can go longer between upgrades, move my data
around less, and have fewer oldies sitting around.  I also wanted the
5yr warranty.  So that's lately meant Seagate.  If it needs to be no
fuss, make sure your seller will take them back for a refund if they
lock up like this.

On Wed, Nov 12, 2008 at 08:19, Ryan Wagoner <rswagoner@gmail.com> wrote:
> I used to buy Seagate drives for their 5 year warranty. However with
> the capacities increasing like they are the 5 vs 3 years doesn't
> really matter as much. Out of the 4 Seagate drives (2 160GB and 2
> 320GB) in my server that are 2.5 years old, the one is already showing
> 13 reallocated sectors. This might be due to non Barracuda drives
> being certified for only 8 hours a day.
>
> Recently I added have 5 Hitachi Deskstar TB drives in two different
> machines which have been working great with mdadm in RAID 1 and 5. I
> actually bought these after using 6 Hitachi Ultrastar TB drives in my
> work's new Dell 2950 server. The server is setup in a 2 drive RAID 1
> and a 4 drive RAID 5 for data archival and has worked flawlessly.
>
> The Hitachi's are in the same price range as the Seagate Barracuda's
> and offer 24/7 runtime and a 1 in 10^15 error rate vs 10^14 for
> Seagate.
>
> Any reason you are using RAID 0 for your server? Normally when I think
> of a server reliability comes to mind and RAID 0 doesn't offer any.
> I'm assumming you make nightly or weekly backups?
>
> Ryan
>
> On Wed, Nov 12, 2008 at 8:12 AM, Henry, Andrew <andrew.henry@logica.com> wrote:
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: OT: Tips for good hard drives for a home server

[Bill Davidsen]

Ryan Wagoner wrote:
> I used to buy Seagate drives for their 5 year warranty. However with
> the capacities increasing like they are the 5 vs 3 years doesn't
> really matter as much. Out of the 4 Seagate drives (2 160GB and 2
> 320GB) in my server that are 2.5 years old, the one is already showing
> 13 reallocated sectors. This might be due to non Barracuda drives
> being certified for only 8 hours a day.
>   
Note that Seagate makes two similar but not quite drives in many 
capacities. As example the drives ending with "AS" or "A" are desktop, 
and those ending with "NS" are for server use. Now the recent "ES" line 
shows 7x24 for the duty cycle, and 1.2M hours MTBF. I doubt you will 
have a problem with longevity.

The 500GB runs <$100, the TB ~ $210.

These are probably a good fit with your budget and reliability needs.

Anyone who has a pointer to information on the "write same" command for 
raid which Seagate mentions, or what the "SV" line of drives actually 
offer could enlighten us.

-- 
Bill Davidsen <davidsen@tmr.com>
  "Woe unto the statesman who makes war without a reason that will still
  be valid when the war is over..." Otto von Bismark 

Re: OT: Tips for good hard drives for a home server

[Mikael Abrahamsson]

On Thu, 13 Nov 2008, Bill Davidsen wrote:

> These are probably a good fit with your budget and reliability needs.

It's important to note the difference between the drives aimed for raid 
use and the ones aimed for non-raid use. This has been said before, but I 
think it's worth saying again, as I was hit by this.

If there is a problem reading a block the raid capable drives will return 
an uncorrectable error very quickly, relying on the raid controller to 
re-calculate parity and re-write the block. A desktop drive will try to 
read the block for several seconds until it fails, and in my case, it 
usually succeeded in reading it, meaning my reads from the raid were 
stalling.

So, if you want your raid to work well, get the enterprise class drives, 
they are rated for long term use, and more importantly, they have the 
firmware to play well in a raid environment.

Looking at the md code in linux, would it be possible to do some work 
around here in that if a drive read operationstalls, let's try to read 
from the other drives and then re-write the block on the drive that 
stalled?

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se

Re: OT: Tips for good hard drives for a home server

[Billy Crook]

Obviously RAID-class drives benefit in hardware raid (with hardware
raid controllers).  But do RAID-class drives benefit when used on a
non-raid hardware controller, with linux software raid (mdadm)?  What
about a hardware raid controller in JBOD mode?

Are the raid-class drives supposed to be used:
 - in a raid fashion
or
 - on a hardware raid controller
or both?

Re: OT: Tips for good hard drives for a home server

[Mikael Abrahamsson]

On Fri, 14 Nov 2008, Billy Crook wrote:

> Obviously RAID-class drives benefit in hardware raid (with hardware
> raid controllers).  But do RAID-class drives benefit when used on a
> non-raid hardware controller, with linux software raid (mdadm)?  What
> about a hardware raid controller in JBOD mode?

This is not a HW vs SW issue, it has to to with the behaviour of the 
drives in conjunction with the OS when a certain thing happens.

In a non-raid environment, you want to read the data at any cost, so 
waiting 2 seconds for it to read is no real problem, you just want the 
data.

In a raid environment you can reproduce the block by way of mirror or 
parity, so you want the read to fail after a short time so it won't delay
the reading of the data.

So as long as md can re-write a faulty block (which it can from 2.6.15 (or 
.16 or .17, I don't remember), you should have raid firmware in your 
drives for best performance.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se

Re: OT: Tips for good hard drives for a home server

[Greg Freemyer]

On Fri, Nov 14, 2008 at 8:40 AM, Mikael Abrahamsson <swmike@swm.pp.se> wrote:
<snip>
> So as long as md can re-write a faulty block (which it can from 2.6.15 (or
> .16 or .17, I don't remember), you should have raid firmware in your drives
> for best performance.

Does it also do background scans looking for unreadable sectors, or
does it just wait for it to occur naturally?

Greg
-- 
Greg Freemyer
Litigation Triage Solutions Specialist
http://www.linkedin.com/in/gregfreemyer
First 99 Days Litigation White Paper -
http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf

The Norcross Group
The Intersection of Evidence & Technology
http://www.norcrossgroup.com

Re: OT: Tips for good hard drives for a home server

[Mikael Abrahamsson]

On Fri, 14 Nov 2008, Greg Freemyer wrote:

> Does it also do background scans looking for unreadable sectors, or does 
> it just wait for it to occur naturally?

As far as I know, you have to issue/schedule a full scan for it to find 
the errors, it won't do continous background scanning like some hw 
controllers out there.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se

Re: OT: Tips for good hard drives for a home server

[Richard Scobie]

Mikael Abrahamsson wrote:
> On Fri, 14 Nov 2008, Billy Crook wrote:
> 
>> Obviously RAID-class drives benefit in hardware raid (with hardware
>> raid controllers).  But do RAID-class drives benefit when used on a
>> non-raid hardware controller, with linux software raid (mdadm)?  What
>> about a hardware raid controller in JBOD mode?
> 
> This is not a HW vs SW issue, it has to to with the behaviour of the 
> drives in conjunction with the OS when a certain thing happens.
> 
> In a non-raid environment, you want to read the data at any cost, so 
> waiting 2 seconds for it to read is no real problem, you just want the 
> data.
> 
> In a raid environment you can reproduce the block by way of mirror or 
> parity, so you want the read to fail after a short time so it won't delay
> the reading of the data.

Here is a paper about the Western  Digital feature "TLER", which is used 
in all their RE series RAID drives.

http://www.wdc.com/en/library/sata/2579-001098.pdf

In addition, these drives are better able to cope with the problem of 
mechanical vibration/resonance that occurs when multiple drives are 
mounted in close proximity:

http://www.wdc.com/en/library/sata/2579-001079.pdf

These features will benefit HW and SW RAID implementations.

I have no association with Western Digital, other than as a satisfied user.

Regards,

Richard

Re: OT: Tips for good hard drives for a home server

[Justin Piszcz]

On Sat, 15 Nov 2008, Richard Scobie wrote:

> Mikael Abrahamsson wrote:
>> On Fri, 14 Nov 2008, Billy Crook wrote:
>> 
>>> Obviously RAID-class drives benefit in hardware raid (with hardware
>>> raid controllers).  But do RAID-class drives benefit when used on a
>>> non-raid hardware controller, with linux software raid (mdadm)?  What
>>> about a hardware raid controller in JBOD mode?
>> 
>> This is not a HW vs SW issue, it has to to with the behaviour of the drives 
>> in conjunction with the OS when a certain thing happens.
>> 
>> In a non-raid environment, you want to read the data at any cost, so 
>> waiting 2 seconds for it to read is no real problem, you just want the 
>> data.
>> 
>> In a raid environment you can reproduce the block by way of mirror or 
>> parity, so you want the read to fail after a short time so it won't delay
>> the reading of the data.
>
> Here is a paper about the Western  Digital feature "TLER", which is used in 
> all their RE series RAID drives.
>
> http://www.wdc.com/en/library/sata/2579-001098.pdf
>
> In addition, these drives are better able to cope with the problem of 
> mechanical vibration/resonance that occurs when multiple drives are mounted 
> in close proximity:
>
> http://www.wdc.com/en/library/sata/2579-001079.pdf
>
> These features will benefit HW and SW RAID implementations.
>
> I have no association with Western Digital, other than as a satisfied user.
>

I have enabled TLER on all of my Velociraptors, we will see if they 'hang'
up anymore and drop out of the raid or just throw bad sector errors right
away, however, I am not sure md(Linux) can handle this, where as a 3ware card
remaps the bad sector, the kernel does not (or at least I have never seen it
do it on my system), instead the drive shows an Uncorrectable_Sector or 
similar..

Justin.

RE: Tips for good hard drives for a home server

[David Lethe]

> -----Original Message-----
> From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
> owner@vger.kernel.org] On Behalf Of Henry, Andrew
> Sent: Wednesday, November 12, 2008 7:12 AM
> To: linux-raid@vger.kernel.org
> Subject: OT: Tips for good hard drives for a home server
> 
> I know this is not md related at all, but this list is read by many
> that are very familiar with hard drive technology, so it's probably the
> best place to ask...hope you all don't mind...
> 
> I've been using an old laptop as a server with external USB Western
> Digital MyBooks as my file system: RAID-0 on 2 500GB MyBooks.  I've had
> quite a few problems with them and one person on this list even
> suggested simply getting rid of them as they are really cr*p according
> to his personal experience.  They are, so I am.  Running a 'server' on
> a laptop turned out to not be the great idea I thought it was (although
> inbuilt monitor/keyboard and 'ups' as well as small footprint/less heat
> was a definite plus)
> 
> So I'm building a new tower server now as my home server and don't want
> to make another poor purchasing decision.  The problem is that most HDD
> manufacturers do not specify spindle count and concurrent
> transactions/iops on their data sheets.
> 
> So if I was in the market for a 'standard' desktop internal 3.5" SATA
> disc, which is the 'best' option?  I'm looking for 500GB in RAID-0 with
> possibility of adding another 500GB array at a later date for RAID 0+1.
> 
> The price of ultra-performance desktop drives is a bit too steep for my
> tastes, so WD Velociraptor or Hitachi UltraStars are not really what I
> am after, unless of course there are no other options in terms of
> performance in the standard desktop market.
> 
> Any tips appreciated.
> 
>  --andrew
Andrew -- Read the full specs, the ones not typically put on the outside of the box.  
Did you know that those 'standard' desktop SATA disks are typically rated for 2400
hrs use per year?

Granted that doesn't mean those cheap disks are going to die at the end of the 100th
day of use in any given year, but you can't ignore the fact that server class drives
are not just ultra-performance disks .. those drives are designed for 24x7x365 use.

So if you're trying to avoid making another poor purchasing decision, then DON'T be 
such a cheapskate, especially since you are running RAID0.  Buy the more expensive disks.

Re: Tips for good hard drives for a home server

[Leandro Tracchia]

i recently bought the 2 of the WD RE3 750GB and using them with linux
raid level 1. time will only tell how these hard drives hold up. but
aside from the Velociraptos (which only go up to 300GB) these seem to
be top quality in their line.

On Wed, Nov 12, 2008 at 9:22 AM, David Lethe <david@santools.com> wrote:
>
>
>> -----Original Message-----
>> From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
>> owner@vger.kernel.org] On Behalf Of Henry, Andrew
>> Sent: Wednesday, November 12, 2008 7:12 AM
>> To: linux-raid@vger.kernel.org
>> Subject: OT: Tips for good hard drives for a home server
>>
>> I know this is not md related at all, but this list is read by many
>> that are very familiar with hard drive technology, so it's probably the
>> best place to ask...hope you all don't mind...
>>
>> I've been using an old laptop as a server with external USB Western
>> Digital MyBooks as my file system: RAID-0 on 2 500GB MyBooks.  I've had
>> quite a few problems with them and one person on this list even
>> suggested simply getting rid of them as they are really cr*p according
>> to his personal experience.  They are, so I am.  Running a 'server' on
>> a laptop turned out to not be the great idea I thought it was (although
>> inbuilt monitor/keyboard and 'ups' as well as small footprint/less heat
>> was a definite plus)
>>
>> So I'm building a new tower server now as my home server and don't want
>> to make another poor purchasing decision.  The problem is that most HDD
>> manufacturers do not specify spindle count and concurrent
>> transactions/iops on their data sheets.
>>
>> So if I was in the market for a 'standard' desktop internal 3.5" SATA
>> disc, which is the 'best' option?  I'm looking for 500GB in RAID-0 with
>> possibility of adding another 500GB array at a later date for RAID 0+1.
>>
>> The price of ultra-performance desktop drives is a bit too steep for my
>> tastes, so WD Velociraptor or Hitachi UltraStars are not really what I
>> am after, unless of course there are no other options in terms of
>> performance in the standard desktop market.
>>
>> Any tips appreciated.
>>
>>  --andrew
> Andrew -- Read the full specs, the ones not typically put on the outside of the box.
> Did you know that those 'standard' desktop SATA disks are typically rated for 2400
> hrs use per year?
>
> Granted that doesn't mean those cheap disks are going to die at the end of the 100th
> day of use in any given year, but you can't ignore the fact that server class drives
> are not just ultra-performance disks .. those drives are designed for 24x7x365 use.
>
> So if you're trying to avoid making another poor purchasing decision, then DON'T be
> such a cheapskate, especially since you are running RAID0.  Buy the more expensive disks.
>
>

RE: Tips for good hard drives for a home server

[Henry, Andrew]

> Any reason you are using RAID 0 for your server? Normally when I think of a server reliability  comes to mind and RAID 0 doesn't offer any.
> I'm assumming you make nightly or weekly backups?


Im using RAID 0 because I am not willing to shell out for several drives.  2 at once is my breaking point.  This is only a *home* server, and in my opinion, I think im already being way more conscious of reliability by choosing RAID 0 compared to average Joe that goes for a Windows Home Server with a single hard drive

I do not currently have backups of my RAID 0 array: it is being used *for* my backup sets.  My data is stored on my desktop PC at the moment and im doing incremental tar backups to my RAID 0 disk.  There are other data on the array that I do not have on my desktop, but I have original media for these (music/movie library) and loss of this would be more inconvenience of having to rip the discs to hard drive again (very time consuming).


> i recently bought the 2 of the WD RE3 750GB and using them with linux
> raid level 1. time will only tell how these hard drives hold up. but
> aside from the Velociraptos (which only go up to 300GB) these seem to
> be top quality in their line.

I've looked at the specs of the WD RE3, the Seagate ES.2, the Hitachi Ultrastar and Samsung Spinpoint F1, and the RE3 does seem to have the edge.  It is double the cost of the drive I was considering but thanks to all the tips I received, I think I will go with the RE3.

One thing im not sure of: Is load/unload cycle equivalent to start/stop count?  WD has load cycle of 300.000 but Hitach/Samsung only 50.000 for 'start/stop count'.

--andrew

Re: Tips for good hard drives for a home server

[Ferg]

Hi Andrew,

I think you are going to need to duck with such a statement:

On Nov13,2008, at 12:11, Henry, Andrew wrote:

>> Any reason you are using RAID 0 for your server? Normally when I  
>> think of a server reliability  comes to mind and RAID 0 doesn't  
>> offer any.
>> I'm assumming you make nightly or weekly backups?

> Im using RAID 0 because I am not willing to shell out for several  
> drives.  2 at once is my breaking point.  This is only a *home*  
> server, and in my opinion, I think im already being way more  
> conscious of reliability by choosing RAID 0 compared to average Joe  
> that goes for a Windows Home Server with a single hard drive

RAID 0 is actually less reliable than a single drive.  Since you lose  
the array when any of the component drives dies, then the  
"reliability" is equal to the "reliability" of the least reliable  
drive divided by the number of drives you have.....!

I've been watching this thread with interest as I'm about to replace a  
4 disc RAID10 SCSI array for a home server with similar SATA drives.   
I'm probably going to go with the Seagate Barracuda ES 1TB drives  
(ST31000340NS ). Bit expensive for a home server, and they do not have  
a reputation as being quiet, but they should last me a good while....!

Cheers
Chris

http://scotgate.org   AIM#fergycool   Skype#fergycool
"cease to exist, giving my goodbye, drive my car into the ocean, you  
think
I'm dead, but i sail away, on a wave of mutilation!"

RE: Tips for good hard drives for a home server

[Henry, Andrew]

>
> Hi Andrew,
>
> I think you are going to need to duck with such a statement:
>


ive got a bit mouth and I don't always think before I speak.   Bad combination.

FYI I was reading the data sheet of the ES.2 drives (and data sheets from the other manufacturers) and they all say about 27-29 dB is the seek noise...not too shabby.  What is the decibel rating of the ES drives?

This with reliability...doesn't it depend on how you look at it?  I mean, 2 drives does increase the chances of one of them failing, but the data is mirrored...doesn't that mean that *recovery* of drive failure is increased, even if *reliability* is decreased?

--andrew

>
> >> Any reason you are using RAID 0 for your server? Normally when I
> >> think of a server reliability  comes to mind and RAID 0 doesn't
> >> offer any.
> >> I'm assumming you make nightly or weekly backups?
>
> > Im using RAID 0 because I am not willing to shell out for several
> > drives.  2 at once is my breaking point.  This is only a *home*
> > server, and in my opinion, I think im already being way more
> > conscious of reliability by choosing RAID 0 compared to average Joe
> > that goes for a Windows Home Server with a single hard drive
>
> RAID 0 is actually less reliable than a single drive.  Since you lose
> the array when any of the component drives dies, then the
> "reliability" is equal to the "reliability" of the least reliable
> drive divided by the number of drives you have.....!
>
> I've been watching this thread with interest as I'm about to replace a
> 4 disc RAID10 SCSI array for a home server with similar SATA drives.
> I'm probably going to go with the Seagate Barracuda ES 1TB drives
> (ST31000340NS ). Bit expensive for a home server, and they do not have
> a reputation as being quiet, but they should last me a good while....!
>
> Cheers
> Chris
>
> http://scotgate.org   AIM#fergycool   Skype#fergycool
> "cease to exist, giving my goodbye, drive my car into the ocean, you
> think
> I'm dead, but i sail away, on a wave of mutilation!"

RE: Tips for good hard drives for a home server

[Henry, Andrew]

Oh crap!

The penny just dropped.

--andrew

RE: Tips for good hard drives for a home server

[Henry, Andrew]

Panic over.  Apart from the fact I made a fool of myself, I have nothing to worry about!  I simply do a search and replace of all my mails in this thread and replace RAID-0 with RAID-1 :)

 [andrew@k2 ~]$ cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb1[1] sda1[0]
      488383936 blocks [2/2] [UU]

unused devices: <none>
[andrew@k2 ~]$

Re: Tips for good hard drives for a home server

[Ferg]

:-)

Better it drops now (even on a public list), than 6 months down the  
line when all your precious files are lost!

I think that all us home users on the list (as opposed to the storage  
professionals here) should always repeat before going to bed... " raid  
is not backup, raid is not backup, raid is not backup........"

Cheers
Chris

On Nov13,2008, at 12:42, Henry, Andrew wrote:

> Oh crap!
>
> The penny just dropped.
>
> --andrew
>
>

Re: Tips for good hard drives for a home server

[Ryan Wagoner]

Actually a single drive is more reliable than 2 drives in RAID 0. If
either drive fails all your data is gone. RAID 0 is intended for
performance only. Personally I would buy the non enterprise class
drives and get 3 for the price of 2 and do RAID 5.

Just a thought.

Ryan

On Thu, Nov 13, 2008 at 7:11 AM, Henry, Andrew <andrew.henry@logica.com> wrote:
>> Any reason you are using RAID 0 for your server? Normally when I think of a server reliability  comes to mind and RAID 0 doesn't offer any.
>> I'm assumming you make nightly or weekly backups?
>
>
> Im using RAID 0 because I am not willing to shell out for several drives.  2 at once is my breaking point.  This is only a *home* server, and in my opinion, I think im already being way more conscious of reliability by choosing RAID 0 compared to average Joe that goes for a Windows Home Server with a single hard drive
>
> I do not currently have backups of my RAID 0 array: it is being used *for* my backup sets.  My data is stored on my desktop PC at the moment and im doing incremental tar backups to my RAID 0 disk.  There are other data on the array that I do not have on my desktop, but I have original media for these (music/movie library) and loss of this would be more inconvenience of having to rip the discs to hard drive again (very time consuming).
>
>
>> i recently bought the 2 of the WD RE3 750GB and using them with linux
>> raid level 1. time will only tell how these hard drives hold up. but
>> aside from the Velociraptos (which only go up to 300GB) these seem to
>> be top quality in their line.
>
> I've looked at the specs of the WD RE3, the Seagate ES.2, the Hitachi Ultrastar and Samsung Spinpoint F1, and the RE3 does seem to have the edge.  It is double the cost of the drive I was considering but thanks to all the tips I received, I think I will go with the RE3.
>
> One thing im not sure of: Is load/unload cycle equivalent to start/stop count?  WD has load cycle of 300.000 but Hitach/Samsung only 50.000 for 'start/stop count'.
>
> --andrew
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

RE: Tips for good hard drives for a home server

[Henry, Andrew]

Huh!?

RAID 0 is mirroring isn't it??  If one drive fails, you still have the other one with the mirrored data to recover from?  You're thinking of RAID 1.

--andrew

andrew henry
+46 (0)40-251144


> -----Original Message-----
> From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-owner@vger.kernel.org] On Behalf Of
> Ryan Wagoner
> Sent: 13 November 2008 13:36
> To: linux-raid@vger.kernel.org
> Subject: Re: Tips for good hard drives for a home server
>
> Actually a single drive is more reliable than 2 drives in RAID 0. If
> either drive fails all your data is gone. RAID 0 is intended for
> performance only. Personally I would buy the non enterprise class
> drives and get 3 for the price of 2 and do RAID 5.
>
> Just a thought.
>
> Ryan
>
> On Thu, Nov 13, 2008 at 7:11 AM, Henry, Andrew <andrew.henry@logica.com> wrote:
> >> Any reason you are using RAID 0 for your server? Normally when I think of a server reliability
> comes to mind and RAID 0 doesn't offer any.
> >> I'm assumming you make nightly or weekly backups?
> >
> >
> > Im using RAID 0 because I am not willing to shell out for several drives.  2 at once is my
> breaking point.  This is only a *home* server, and in my opinion, I think im already being way
> more conscious of reliability by choosing RAID 0 compared to average Joe that goes for a
> Windows Home Server with a single hard drive
> >
> > I do not currently have backups of my RAID 0 array: it is being used *for* my backup sets.  My
> data is stored on my desktop PC at the moment and im doing incremental tar backups to my RAID
> 0 disk.  There are other data on the array that I do not have on my desktop, but I have original
> media for these (music/movie library) and loss of this would be more inconvenience of having to
> rip the discs to hard drive again (very time consuming).
> >
> >
> >> i recently bought the 2 of the WD RE3 750GB and using them with linux
> >> raid level 1. time will only tell how these hard drives hold up. but
> >> aside from the Velociraptos (which only go up to 300GB) these seem to
> >> be top quality in their line.
> >
> > I've looked at the specs of the WD RE3, the Seagate ES.2, the Hitachi Ultrastar and Samsung
> Spinpoint F1, and the RE3 does seem to have the edge.  It is double the cost of the drive I was
> considering but thanks to all the tips I received, I think I will go with the RE3.
> >
> > One thing im not sure of: Is load/unload cycle equivalent to start/stop count?  WD has load
> cycle of 300.000 but Hitach/Samsung only 50.000 for 'start/stop count'.
> >
> > --andrew
> > --
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Re: OT: Tips for good hard drives for a home server

[Robin Hill]

--- billycrook@gmail.com wrote:

> Obviously RAID-class drives benefit in hardware raid (with hardware
> raid controllers).  But do RAID-class drives benefit when used on a
> non-raid hardware controller, with linux software raid (mdadm)?  What
> about a hardware raid controller in JBOD mode?
> 
> Are the raid-class drives supposed to be used:
>  - in a raid fashion
> or
>  - on a hardware raid controller
> or both?
> 
From what I can tell, modern RAID-class drives are just certified for 24x7 operation.  Some may also have some features tweaked for hardware RAID (e.g. disabling write caching) but I've not seen this on any I've bought.  I'd recommend using them in any situation where you're going to be running the system full-time, whether they're standalone or in software or hardware RAID.

Cheers,
    Robin