Re: SSD and RAID question

[zxq9]

Hmm. Never had a bad hardware RAID controller. Had several
mechanical hard drives go bad.

Anyone have an opinion(s) on SSD's in a small work group server?


We've had very good luck with SSDs (singly on workstations or spanned 
volumes on servers) as primary storage mirroring to a spanned volume of 
cheap spinning disks. Never had an SSD failure (yet), but the cheap disk 
backup is live anyway so we're not too worried.


We *do* have a schedule for replacement based on the historical write 
average on the SSDs, though. Eventually they will brick so before that 
we have to replace them and planning it ahead of time is way better than 
living in panic-replacement mode whenever they eventually die. At the 
moment it looks like workstations won't even come close to needing 
replacements before the systems are end-of-life anyway, but the servers 
are a different issue (some of them are under considerable load, and 
will probably require replacement every 2 years to be totally safe).


As for the OP's question about trim: trim is available as a mount option 
as well as a few others that limit the tiny-write problem (like the 
noatime option and putting various cache directories in tmpfs in RAM 
instead of on disk, etc.) and change the way the seek/writes are 
scheduled (default is optimized for platters, which is a deoptimization 
for SSDs). You can find a wealth of information on the net about these 
issues so I won't bore you with the details here.

Re: SSD and RAID question

[Todd And Margo Chester]

On 09/02/2012 08:26 PM, Nathan wrote:

On Sun, Sep 2, 2012 at 6:33 PM, Todd And Margo Chester
mailto:toddandma...@gmail.com>> wrote:

Hi All,

On several Windows machines lately, I have been using
Intel's Cherryville enterprise SSD drives.  They work
very, very well.

Cherryville drives have a 1.2 million hour MTBF (mean time
between failure) and a 5 year warranty.

I have been thinking, for small business servers
with a low data requirement, what would be the
risk of dropping RAID in favor of just one of these
drives?

Seems to me the RAID controller would have a worse
MTBF than a Cherryville SSD drive?

And, does SL 6 have trim stuff built into it?

What do you all think?


In my experience, I've had more problems with hardware RAID controllers
than any other component (hardware OR software) except for traditional
hard drives themselves.  We switched to software RAID (Linux) and ZFS
(*BSD and Solaris)  years ago.

But that's just us.  YMMV.

~ Nathan


Hmm.  Never had a bad hardware RAID controller.  Had several
mechanical hard drives go bad.

Anyone have an opinion(s) on SSD's in a small work group server?

Re: SSD and RAID question

[jdow]

On 2012/09/02 20:26, Nathan wrote:


In my experience, I've had more problems with hardware RAID controllers than any
other component (hardware OR software) except for traditional hard drives
themselves.  We switched to software RAID (Linux) and ZFS (*BSD and Solaris)
  years ago.

But that's just us.  YMMV.


Speaking of software raid, I have four disks that are from a RAID on
a motherboard with the Intel ICH10 controller. They were in RAID 5.
The motherboard is a "was a motherboard" for the most part. I note
that the Linux raid could read the disks in that machine. If I stick
the four disks into four USB<->SATA adapters is it likely the Linux
raid software will be able to piece them together so I can get the
"not so critical" last few bits of effort off them that I've not
been able to keep the motherboard up long enough to get already? (The
native system on the disks was Windows 7 with which I make some real
income.)

If there's a good chance it would work that will change my recovery
strategy a little.

{^_^}

Re: SSD and RAID question

[Nathan]

On Sun, Sep 2, 2012 at 6:33 PM, Todd And Margo Chester <
toddandma...@gmail.com> wrote:

> Hi All,
>
> On several Windows machines lately, I have been using
> Intel's Cherryville enterprise SSD drives.  They work
> very, very well.
>
> Cherryville drives have a 1.2 million hour MTBF (mean time
> between failure) and a 5 year warranty.
>
> I have been thinking, for small business servers
> with a low data requirement, what would be the
> risk of dropping RAID in favor of just one of these
> drives?
>
> Seems to me the RAID controller would have a worse
> MTBF than a Cherryville SSD drive?
>
> And, does SL 6 have trim stuff built into it?
>
> What do you all think?
>
>
In my experience, I've had more problems with hardware RAID controllers
than any other component (hardware OR software) except for traditional hard
drives themselves.  We switched to software RAID (Linux) and ZFS (*BSD and
Solaris)  years ago.

But that's just us.  YMMV.

~ Nathan

SSD and RAID question

[Todd And Margo Chester]

Hi All,

On several Windows machines lately, I have been using
Intel's Cherryville enterprise SSD drives.  They work
very, very well.

Cherryville drives have a 1.2 million hour MTBF (mean time
between failure) and a 5 year warranty.

I have been thinking, for small business servers
with a low data requirement, what would be the
risk of dropping RAID in favor of just one of these
drives?

Seems to me the RAID controller would have a worse
MTBF than a Cherryville SSD drive?

And, does SL 6 have trim stuff built into it?

What do you all think?

Many thanks,
-T

Re : failing installation process SL-63-x86_64-2012-08-02-Everything-DVD

[Charles Elsaesser]

it's better to use the  images
ftp://ftp.scientificlinux.org/linux/scientific/6.3/x86_64/iso/SL-63-x86_64-2012-08-02-Everything-DVD1.iso
and
ftp://ftp.scientificlinux.org/linux/scientific/6.3/x86_64/iso/SL-63-x86_64-2012-08-02-Everything-DVD2.iso
so all softwares will be available locally on two DVDs

at installation time when booting with DVD1 you will chose  your "minimalistic" 
configuration ( when chosing between "development station", etc , ...)

when your 2 DVDs will be burned, you must prepare the partition on which you 
will install the system.

if you do not have enough RAM, then you must also define a swap space.

as far as i have learned you should have at least 2.5GB of RAM

if not, then define swap space according to
Table 16.2 : Recommended System Swap Space
recommendations
( see installation guide at
https://access.redhat.com/knowledge/docs/Red_Hat_Enterprise_Linux/?locale=en-US
i.e.
https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/html-single/Installation_Guide/index.html
)

On lack of memory, installation process will abort or block at DVDs switch , 
request

so if , according to your minimalistic system resources, you have only 1GB, 
previously to installation , create a swap space of 2.5GB at least, to avoid 
blocking or abort on DVDs switch request.

may be the blocking ( looping DVD1 request) is due to lack of memory.

please let us know us know your amount of RAM and also the amount of SWAP 
space, if you defined one

thanks

--- En date de : Ven 31.8.12, Müller-Reineke, Matthias 
 a écrit :

De: Müller-Reineke, Matthias 
Objet: 
À: "'scientific-linux-us...@fnal.gov'" 
Date: Vendredi 31 août 2012, 18h19

Dear Scientific users,

i've tried to install Scientific Linux 6.3 from the image named 
SL-63-x86_64-2012-08-02-Install-DVD.iso .
What ever I try I am told: "Please insert Scientific Linux disc 1 to continue." 
(see appended picture).
The iso image is 4 GB large so i thought it contains everything for a 
standard/small installation.
Is this a bug? I can hardly imagine that the iso image is useless.

Which iso image is for which purpose?
I want to install a minimalistic system from as few media as possible.


Matthias Müller-Reineke

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