[DRBD-user] Dell Server Question

Roof, Morey R. MRoof at admin.nmt.edu
Sat Dec 10 04:49:52 CET 2011

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

Well I might be able to give you such a sent of benchmarks.  I have 2 new servers that are using 3.5" 15k drives so I can pull some random IO patterns and later post them.  Plus I have data from some 2.5" drive sets that can be compared against.


From: John Lauro [mailto:john.lauro at covenanteyes.com]
Sent: Fri 12/9/2011 8:01 PM
To: Roof, Morey R.; drbd-user at lists.linbit.com
Subject: RE: [DRBD-user] Dell Server Question

You are correct, it's only 12+2 drives on the R515.  I was confusing it with another server (non Dell).


You would think that 2.5" drives would be faster.  Maybe it's just the particular drives I have tested with.  Have you done any benchmarks, especially random I/O?  It was only 10K on the 2.5 drives vs.  15K on the 3.5 with much higher capacities.  For my needs, I am mostly interested in random I/O than sequential.



From: Roof, Morey R. [mailto:MRoof at admin.nmt.edu] 
Sent: Friday, December 09, 2011 9:34 PM
To: John Lauro; drbd-user at lists.linbit.com
Subject: RE: [DRBD-user] Dell Server Question


The R515 only does 12 drives, not 16 drives and the two internal mean a server shutdown for replacement which is slight annoying.


One of the IBM servers (which also has an LSI card) holds 28 2.5" drives.  It is the model x3630 M3 and it is another I have been looking at.


Very strange that you would say that 3.5 are faster than 2.5.  With the higher densities of the 2.5 drives in the 10k range the larger bit densities per cm^2 means a much higher data transfer speed.  Also, if you look at the seek times they are pretty much identical and a full drive sweep is a bit faster on the 2.5 than the 3.5 since the drive is smaller.





From: John Lauro [mailto:john.lauro at covenanteyes.com]
Sent: Fri 12/9/2011 5:21 PM
To: Roof, Morey R.; 'Kushnir, Michael (NIH/NLM/LHC) [C]'; drbd-user at lists.linbit.com
Subject: RE: [DRBD-user] Dell Server Question

Supermicro might be your best option, but for comparisons a more standard
model for a Dell is the R515 (or 510) instead of the C-series, with 16
3.5" drives and 2 2.5" drives all in 2U.  Unless you count SSD, despite
the higher density (24 vs 16) I haven't found 2.5" drives that really
match the performance of 3.5" drives, although they are getting closer.
Much easier to find trays/drives for the R515 than the C-series.

PS: Often you can get Dell to match prices on systems if you give them a
quote to compete with.  Given the shortage of hard drives, it might be
harder than normal right now...

My biggest annoyance with Dell (and LSI as they make the controllers), is
they don't properly do Raid 1/10 despite their configuration info implying
they do.  They really only read from 1 drive, so performance-wise you are
better off not utilizing the hardware RAID and making a md raid 1/10 on
top of the individual drives.  That said, their RAID 5 performance is

> -----Original Message-----
> From: drbd-user-bounces at lists.linbit.com [mailto:drbd-user-
> bounces at lists.linbit.com] On Behalf Of Roof, Morey R.
> Sent: Friday, December 09, 2011 2:54 PM
> To: Kushnir, Michael (NIH/NLM/LHC) [C]; drbd-user at lists.linbit.com
> Subject: Re: [DRBD-user] Dell Server Question
> Hi Michael,
> Thanks a bunch for the information.  I was looking at the Supermicro
> boxes (used quite a few of them) and was a bit curious about the Dell
> offering.  I'm glad to know I shouldn't use them and I believe I will
> just go with the Supermicro setup as I was planning.
> One big issue I wanted to know was the backplane for the HDDs.  Having
> it split like that it is really stupid.  With the supermicro chassis
> they can be ordered with dual expander chips so cards like the Megaraid
> can load balance the IO to both ports on the HDDs.
> Pretty sad that Dell would act like that but it is their loss.
> Thanks again,
> Morey
> -----Original Message-----
> From: Kushnir, Michael (NIH/NLM/LHC) [C]
> [mailto:michael.kushnir at nih.gov]
> Sent: Friday, December 09, 2011 11:53 AM
> To: Roof, Morey R.; drbd-user at lists.linbit.com
> Subject: RE: Dell Server Question
> Hi Morey,
> I am using two C2100 servers with 2.5" inch chassis with DRBD. To save
> you the long read, my quick and short recommendation is: AVOID THEM LIKE
> For the money, get
> http://www.supermicro.com/products/chassis/4U/417/SC417E16-R1400U.cfm
> (72-bay - 4U) or the
> http://www.supermicro.com/products/chassis/2U/216/SC216E16-R1200U.cfm
> (24 bay - 2U) instead.
> If you want more detailed info, read on! :)
>  My servers came with the LSI 9260-8i RAID cards, single E5620 CPU, 12GB
> RAM, and the Intel based "mezzanine" dual-port 10GbE card. The backplane
> is split with 12 slots connected to one port on the RAID card, and 12
> slots on the other.
> CPU and RAM:
> I've found the E5620 is more than capable of handling the load from DRBD
> and IET (software iscsi target). 12GB RAM is also ample for my needs.
> Network:
> I've found the Intel 10GbE card to be a good performer. I am using it
> with Finisar SFP+ modules and have it connected to a Cisco 4900 switch
> with Cisco optics on the switch end. I have the two ports in an LACP
> (mode 4) bond.  I am getting ping latencies of about 0.23-0.3ms. I'm
> happy with that performance.
> I have my OS (RHEL 5) and swap on a pair of 500GB SATA2 disks in RAID1,
> and my DRBD on a RAID10 made up of 10 Constellation.2 1TB disks.
> Metadata is set to internal. The max replication rate (for the initial
> sync)  was ~3.2Gbits/s (measured by iftop).
> Issues:
> 1.
> This server is not actually made by Dell. It is completely outsourced to
> another manufacturer. I was not able to get any useful support from Dell
> with any issues that I had. Their support people simply don't know crap
> about this server, how to use it, or how to manage it. Considering that
> I'm with the Federal government, and go through a dedicated support
> team, that should say something. Dell was not even able to tell me what
> software to use to manage the RAID array and failure notifications.
> Dell kept telling me that the LSI command line utility is the only way
> to go, and that the server, "is intended for hyper scale environments
> where the expectation is that a failed server would just fail and be
> replaced by another, and where administrators should know how to manage
> such an environment."
>  Thankfully, LSI support people pointed me to their GUI which unlocks
> great features like SNMP and SMTP notifications, SSD caching, and SSD
> protector for SSD RAID.
> 2.
> Because the hardware is not actually "made" by Dell, this server is not
> compatible with Open Manage and you can't update your drivers firmware
> from Dell's yum repositories firmware.
> 3.
> Drive trays--- wow was this a surprise for me!!! Dell has a new policy
> where they do not sell drive trays without hard drives in them. As you
> might know, Dell's drives are highly overpriced. They will also not sell
> you a server fully populated with trays unless you get it fully
> populated with drives. We bought over $100k of Dell equipment this year,
> and they would not make an exception and give us the drive trays.
> So, finally, we relented, and we bought 16 (8 for each server) Crucial
> M4 512GB SSDs from Dell for about $13k. Once we bought the drives, we
> asked for trays. Dell told us to go... The policy is that trays are only
> supplied with Dell BRAND drives, not any drives purchased from Dell.
> We relented again, and asked Dell to sell us their cheapest hard drives
> just to get trays. Dell told us that they cannot, because they are out
> of hard drives due to flooding in Thailand. And they cannot just charge
> us for drives and ship only the trays. GRR!!! Bastards!!!
>  I've tried finding the trays online. It took me months to find some at
> codemicro.com. Then they suddenly sold out of all 400+ units. So, the
> last batch, I had to buy on eBay. I thank God that Ivan from New Jersey
> was able to find some to put them on eBay.
> So, my recommendation is: STAY AWAY! Get the SuperMicro chassis (it
> comes with all 72 drive trays and plenty of expansion capacity. Get ASUS
> server motherboards (I use them in my private lab), Myri 10GbE  NICs (I
> use them in other production servers), and LSI 9260-8i (or better) RAID
> cards. You will be in a good place in terms of hardware and money spent.
> Best,
> Michael Kushnir
> Lead VMware and UNIX Systems Administrator
> Communications Engineering Branch,
> Lister Hill National Center for Biomedical Communications,
> National Library of Medicine,
> National Institutes of Health
> -----Original Message-----
> From: Roof, Morey R. [mailto:MRoof at admin.nmt.edu]
> Sent: Thursday, December 08, 2011 1:30 PM
> To: drbd-user at lists.linbit.com
> Subject: [DRBD-user] Dell Server Question
> Hi Everyone,
> Anyone out there using a Dell Poweredge C2100 with the 24 2.5" HDD
> backplane?  I'm curious to know a little about the backplane, mainly if
> it is a dual port backplane where the RAID controller can use both ports
> on the SAS drives to load balance the IO operations.  Dell's website
> isn't very specific on this point.  Also, some information about how the
> server seems work with DRBD would be very helpful to me.
> Thanks,
> Morey
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