[AusNOG] Server/HD Question

Judd Howie juddhowie at gmail.com
Thu Feb 14 15:45:32 EST 2013


Tony's post got me thinking..another option..
Grab a little HP NL40 (cheap as chips), fill it full of SATA (or add 2 SATA
+ 2 SSD (ZIL+L2ARC)) drives and install ZFS (Openindiana/FreeNAS/etc).
Boot off USB on your 1950 (if it's a II it should have internal USB) and
then mount the storage via iSCSI/NFS.
ZFS is a very good "software RAID" solution.
The HP NL box is tiny but not rack friendly though.  8+(



On 14 February 2013 15:26, Tony <td_miles at yahoo.com> wrote:

> Check the RAID card then, a lot of the ones doing hardware RAID-1 don't
> write any extra meta-data to the disk or mess the disk stucture up, they
> just write the data to both disks at the same time. This means that you
> wouldn't have any concerns about what happens if your RAID card fails as
> either disk can be put into any machine and used as just a normal disk. I
> haven't played with server hardware for ages, but the entry-level IBM RAID
> using LSI Logic controllers was like this, two disks, plain mirroring of
> the disks to each other. Have to be very careful when replacing a disk
> which one you mirror from/to as the controller doesn't know because there
> is nothing "special" about the disk that it can identify the "RAID
> structure" on the disk.
>
>
> Whilst we're tlaking about SSD & SAS/SATA, you can also get RAID
> controllers that have the option to add SSD as cache disks to store
> frequently used data on to give some of the benefit of fast access to SSD
> without worrying about them dropping dead quite so much.
>
>
> Most hardware RAID controllers have a number of features to avoid the
> issue of having to find the same identical model controller if one dies,
> but this is a concern. There are several ways to work around this, you can
> purchase HW maintenance from your vendor and rely on them to have spares
> for you. If you think RAID controller is a single vulnerability that you
> don't like, you could purchase two and have a hot spare sitting on your
> shelf. You could also build in some redundancy at higher layers so that
> VM's are spread across multiple real machines and recover without downtime
> if one fails, but you're talking bigger $$ there. Then there is the option
> of using something like DRDB to give you a RAID-1 set across two machines
> which is quite interesting:
>
> http://www.drbd.org/
>
>
> regards,
> Tony.
>
>   ------------------------------
> *From:* Skeeve Stevens <skeeve+ausnog at eintellegonetworks.com>
> *To:* Jake Anderson <yahoo at vapourforge.com>
> *Cc:* ausnog at ausnog.net
> *Sent:* Thursday, 14 February 2013 2:02 PM
> *Subject:* Re: [AusNOG] Server/HD Question
>
> The server only has 2 bays in it.  Can VMware do software RAID?
>
> ...Skeeve
>
> *Skeeve Stevens - *eintellego Networks Pty Ltd
> skeeve at eintellegonetworks.com ; www.eintellegonetworks.com
> Phone: 1300 239 038; Cell +61 (0)414 753 383 ; skype://skeeve
> facebook.com/eintellegonetworks ;  <http://twitter.com/networkceoau>
> linkedin.com/in/skeeve
> twitter.com/networkceoau ; blog: www.network-ceo.net
> The Experts Who The Experts Call
> Juniper - Cisco - Cloud
>
>
> On Thu, Feb 14, 2013 at 2:55 PM, Jake Anderson <yahoo at vapourforge.com>wrote:
>
>  On 14/02/13 14:43, Skeeve Stevens wrote:
>
> OK, so today is a day of learning.
>
>  As I said.. I am NOT a server hardware guy.  Based on some of the
> responses, I now have learned that SATA drives will fit into a SAS
> interface (but not the reverse).  This is awesome... I thought they were
> completely different.
>
>  So, it is a DELL 1950 with 32Gb ram, 2 x Dual Core 3Ghz processors.  I
> am still unclear what, if any RAID is on board.
>
> I would stay away from "hardware" raid, if you don't need it for ultimate
> performance use software raid.
> When the computer craps itself, slap the drives into a new host and be
> running again, no need to hunt down the exact same model of raid card.
>
>
>  The server will be used for a dozen VMs.  Centos, general purpose, DNS,
> radius, etc with httpd front end and some mySQL backend, but all low
> performance.  The sort of VMs you commit 128mb of ram to and max at 1-1.5Gb
> ram.
>
> you can never have too much ram, this applies double with VM's ;->
>
>
>  FYI, I know how to manage Vmware and staggering the boots, and so on.
>
>  Oh yeah.. and I did mean 7.2k drives.. ;-)
>
>  So.. now that I know I can use SATA drives... it opens things up a bit.
>
>  I am looking at Ingram.. still some thing I don't understand.
>
>  HP 2TB SATA 6Gb/s 7200 HDD<https://au.ingrammicro.com/_layouts/CommerceServer/IM/ProductDetails.aspx?id=AU01@@2210@@10@@000000000001885395> -
> $292
> HP 2TB SATA 3Gb/s NCQ 7200 HDD<https://au.ingrammicro.com/_layouts/CommerceServer/IM/ProductDetails.aspx?id=AU01@@2210@@10@@000000000001551449> -
> $342
>
>  No idea what NCQ is, and why the faster TP drive is cheaper.  Anyone?
>
> NCQ is native command queing, the HDD will re-order buffered reads on the
> fly for the best average access time.
> Can be a decent gain on a heavy disk load.
>
>
>  These look nice:
>
>  SEAGATE Constellation CS SATA 2TB 3.5" 7200RPM 64 Cache<https://au.ingrammicro.com/_layouts/CommerceServer/IM/ProductDetails.aspx?id=AU01@@2210@@10@@000000000002145465> -
> $159 lots in stock
>  SEAGATE Constellation CS SATA 3TB 3.5" 7200RPM 64 Cache<https://au.ingrammicro.com/_layouts/CommerceServer/IM/ProductDetails.aspx?id=AU01@@2210@@10@@000000000002145467>
>   - $219 lots in stock
>
>  I see some NL drives (assuming what someone said was Near Line) - no
> idea what that is though.
>
>  I was also thinking that if the chassis had the space, I should put a
> little SSD of CF on board to install the ESX onto to keep the OS off the
> drives... thoughts?  My assumption is that once VMware is booted, its disk
> access is minimal.
>
> I would doubly not do this, or if you do, raid them.
> SSD's have the same failure rate as rotating media. Often with worse
> failure properties, one day they just disappear, no degradation, bad
> sectors or anything first.
> I would put a RAID1 in for boot and put your OS on that.
> however you configure the rest of the array, its good if the system can
> still get booted regardless of the degradation.
> Given a number of VM's running partitioning is perhaps a good thing to
> look at, rather than one bigass raid5 array, put a few smaller raid1's in.
> Spread the VM's across the spindles so if a mail system starts thrashing
> grabbing somebodies emails, when their mail client starts pushing it back
> onto the file server you aren't running all that on the same set of
> spindles.
> Be sure to align all the VM's with sector boundary’s. Right the way
> through the chain. IE the VM's internal partitions should start on a
> boundary of the physical disk.
>
>
>
>
> ...Skeeve
>
>  *Skeeve Stevens - *eintellego Networks Pty Ltd
>  skeeve at eintellegonetworks.com ; www.eintellegonetworks.com
> Phone: 1300 239 038; Cell +61 (0)414 753 383 ; skype://skeeve
> facebook.com/eintellegonetworks ; linkedin.com/in/skeeve
> twitter.com/networkceoau ; blog: www.network-ceo.net
>  The Experts Who The Experts Call
>  Juniper - Cisco - Cloud
>
>
> On Thu, Feb 14, 2013 at 1:10 PM, Skeeve Stevens <
> skeeve+ausnog at eintellegonetworks.com> wrote:
>
> Hey guys,
>
>  I know a bit about operating servers, but know bugger all about the
> hardware, especially when it comes to hard drives.
>
>  I am needing to deploy a server for some low performance VM's, and it
> has 32Gb ram, Dual core dual processor 3Ghz... so all good.  Should run a
> few linux VM's on ESX.
>
>  But... hard drives I really don't know about.
>
>  The chassis takes SAS drives.  In it are some small drives and I want to
> upgrade.
>
>  Will 7.5k speed drives be ok on a VMware server if its not for high
> performance processing?  The cost of 15k SAS drives still seem to be rather
> expensive.  I was hoping for 500Gb-600Gb of space.
>
>  Any thoughts on which brand is ok... I will be putting a single drive in
> mirrored (only 2 bays).
>
> ...Skeeve
>
>  *Skeeve Stevens - *eintellego Networks Pty Ltd
>  skeeve at eintellegonetworks.com ; www.eintellegonetworks.com
> Phone: 1300 239 038; Cell +61 (0)414 753 383 ; skype://skeeve
> facebook.com/eintellegonetworks ; linkedin.com/in/skeeve
> twitter.com/networkceoau ; blog: www.network-ceo.net
>  The Experts Who The Experts Call
>  Juniper - Cisco - Cloud
>
>
>
>
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