[Novalug] best hard disk setup for home file server?

Bryan Seitz seitz@bsd-unix.net
Tue Oct 13 13:44:24 EDT 2009


Like RAID6, two sets of parity, ie you can lose 2 disks in a set and still be
ok vs RAID5 in which you can lose only 1.

On Tue, Oct 13, 2009 at 01:33:30PM -0400, covici@ccs.covici.com wrote:
> OK, what the heck is raid Z2?
> 
> Richard Ertel <richard.ertel@gmail.com> wrote:
> 
> 
> > OK so say i want to ditch these two 1.5 TB 3.5" drives in favor of
> > 2.5" drives... in order to keep costs low, i'd want to use them along
> > with my two reliable 1.0 TB 3.5" drives.
> > 
> > 500 gigs seems to be the sweet spot for 2.5" drives right now, at $90
> > or less per drive.
> > 
> > option: add FIVE 500 GB drives to system (would have to get an add-on
> > SATA controller), partition the 1 TB drives into two 500 gig
> > partitions each, then put all NINE 500 gig partitions into a RAID-Z2
> > array yielding 3.5 TB of usable space. (Z2 to account for two
> > partitions on the 1 TB drives)
> > 
> > a) would this work? am i insane? am i cheap?
> > 
> > b) when space upgrade is desired and the new sweet spot for 2.5"
> > drives is 1.0 TB, how should the array then be made? use LVM to
> > combine two 500 gig drives into a 1 TB volume and then RAID-Z the 1 TB
> > partitions (presumably four new 1.0 TB 2.5" drives plus four 500 GB
> > drives = 6 partitions in array = 5 TB)?
> > 
> > On Tue, Oct 13, 2009 at 12:48, William Sutton <william@trilug.org> wrote:
> > > nifty
> > >
> > > William Sutton
> > >
> > > On Tue, 13 Oct 2009, Bryan Seitz wrote:
> > >
> > >> Adapters adapters adapters!
> > >>
> > >> Something like:
> > >>
> > >> http://www.newegg.com/Product/Product.aspx?Item=N82E16816119012
> > >>
> > >> Cheaper ones available but you get the idea. ??A unit with a fan would probably
> > >> be a good idea.
> > >>
> > >> On Tue, Oct 13, 2009 at 12:30:55PM -0400, William Sutton wrote:
> > >>> Out of curiosity for those of us who haven't done it before, how do you
> > >>> mount 8 2.5" drives in 2 optical bays? :-)
> > >>>
> > >>> William Sutton
> > >>>
> > >>> On Tue, 13 Oct 2009, Bryan J Smith wrote:
> > >>>
> > >>>> 8 drives would fit nicely in two optical bays. ??;)
> > >>>>
> > >>>> Your choice. ??I've just noted failure rates of 2.5" v. 3.5" and
> > >>>> I know my experiences aren't alone. ??;)
> > >>>>
> > >>>> I've been in IT departments that stopped considering anything
> > >>>> other than 2.5" drives except for non 24x7 systems (like
> > >>>> nearline or PCs that could quickly be replaced whole).
> > >>>>
> > >>>> Just not worth it to me.
> > >>>>
> > >>>> --
> > >>>> Bryan J Smith - mailto:b.j.smith@ieee.org
> > >>>> http://www.linkedin.com/in/bjsmith
> > >>>> Sent via BlackBerry from T-Mobile
> > >>>>
> > >>>>
> > >>>> -----Original Message-----
> > >>>> From: Richard Ertel <richard.ertel@gmail.com>
> > >>>> Date: Tue, 13 Oct 2009 12:00:38
> > >>>> To: Megan Larko<larkoc@iges.org>
> > >>>> Cc: Novalug<novalug@calypso2.tux.org>
> > >>>> Subject: Re: [Novalug] best hard disk setup for home file server?
> > >>>>
> > >>>> @John:
> > >>>> i'll take the calling my configuration "weird" as a compliment.
> > >>>> actually, the idea of using the remaining 500 gigs on each drive as
> > >>>> another array came from this list, i just then combined them into LVM
> > >>>>
> > >>>> @Bryan:
> > >>>> unfortunately, my storage needs are 3+ TB, so the sheer number of 2.5"
> > >>>> disks required (with redundancy) at 500 GB per disk is what, 7 disks
> > >>>> for RAID-5 and 8 disks for RAID-6? i ran a 8-drive server in the past,
> > >>>> didn't like having that many to worry about. for me, 4 disks is a nice
> > >>>> number and that works out well with 3.5" disks and my current storage
> > >>>> needs.
> > >>>>
> > >>>> @Megan:
> > >>>> thanks for the info about external enclosures and netbooks. yeah, my
> > >>>> previous servers have been made with 160 gig drives, 250 gig drives,
> > >>>> 500, 750, 1TB... over the past 6 years or so. and these 2 damn
> > >>>> identical seagates are the first to ever fail. i still use some of the
> > >>>> 160 gig drives in other machines. all always been 24/7 too.
> > >>>>
> > >>>> On Tue, Oct 13, 2009 at 11:51, Megan Larko <larkoc@iges.org> wrote:
> > >>>>> Richard Ertel wrote:
> > >>>>>
> > >>>>> Ouch! ? I feel your pain.
> > >>>>>
> > >>>>>> in light of the current problems i am having with my home file server,
> > >>>>>> i want to reconsider my choice for how i configured hard disks in my
> > >>>>>> server.
> > >>>>>>
> > >>>>>> as said before, i currently have two 1.5 TB drives and two 1.0 TB
> > >>>>>> drives, all standard 3.5" internal disks.
> > >>>>>>
> > >>>>>> four 1.0 TB partitions are in RAID-5 configuration, and the remaining
> > >>>>>> two 500 GB partitions are RAID-1. these two arrays are combined via
> > >>>>>> LVM into one logical volume of 3.5 TB.
> > >>>>>>
> > >>>>>> my current situation has the new brand new 1.5 TB drives dying, which
> > >>>>>> of course kills all my data. they are identical drives (seagate), same
> > >>>>>> model number, maybe same manufacturing batch. both dying at the same
> > >>>>>> time.
> > >>>>>
> > >>>>> A co-working in my office tried to use the 1.5Tb capacity drives when they
> > >>>>> came out some months ago and he also had them only a short period of time
> > >>>>> before they had a simultaneous failure. ? As the disks were under warranty
> > >>>>> he exchanged them for drives of a smaller capacity (1 Tb).
> > >>>>>>
> > >>>>>> does anyone have any experience RAIDing external USB drives in linux?
> > >>>>>> should i expect reliability to increase if i move all 4 drives to 4
> > >>>>>> external SATA to USB enclosures (5.25" enclosures with fans)? are
> > >>>>>> these enclosures suitable for 24/7 operation? would read and write
> > >>>>>> speed suffer (all transfers are over gigabit network)?
> > >>>>>
> > >>>>> I have personally not created RAIDs of external USB drives. ?I have found
> > >>>>> that even with fans, many external enclosures become uncomfortably (for me)
> > >>>>> warm. ?I really think the external USB enclosures were not designed for 24/7
> > >>>>> generally.
> > >>>>>>
> > >>>>>> if all those USB drives running through a USB hub to a server is ok,
> > >>>>>> then what about ditching my tower and running them all to a netbook as
> > >>>>>> a server? i've seen that argument made once before, citing built-in
> > >>>>>> ups (battery), built-in monitor, low power draw and other factors as
> > >>>>>> big benefits to a netbook as server.
> > >>>>>
> > >>>>> My ASUS EeePC 700 netbook does not run for too many hours (8+) without
> > >>>>> getting warm. ?A two-fan notebook cooler helped this issue. ?Just
> > >>>>> mentioning.....
> > >>>>>>
> > >>>>>> or am i worrying too much and what i have on my hands is just a fluke,
> > >>>>>> and in the future i should mix drive manufacturers/models to avoid
> > >>>>>> simultaneous failure?
> > >>>>>
> > >>>>> I would continue to use similar manufacturer and models in RAID units. ? I
> > >>>>> think the particular drives you have just are not "ready for prime time". ?I
> > >>>>> have done very will with 500Gb and 1Tb drives by Hitachi and Western Digital
> > >>>>> in 24/7 rack-mounted data server systems. ? That said, perhaps an old tower
> > >>>>> with a motherboard allowing multiple drives and good PSU and fans would be
> > >>>>> an option for you? ?It could run a small OS eliminating the netbook on all
> > >>>>> the time and use NFS or SAMBA to share the drives with other computers on
> > >>>>> your network. ?It can have a better pipe than just USB2.0.
> > >>>>> If the data is to be on-line 24/7 might as well put it into a box designed
> > >>>>> to run all the time.
> > >>>>>
> > >>>>> Enjoy your day.
> > >>>>> megan
> > >>>>>
> > >>>>>> _______________________________________________
> > >>>>>> Novalug mailing list
> > >>>>>> Novalug@calypso.tux.org
> > >>>>>> http://calypso.tux.org/mailman/listinfo/novalug
> > >>>>>
> > >>>>>
> > >>>>> --
> > >>>>> I will now bring you up to speed on the situation.
> > >>>>> We know nothing!
> > >>>>> There, you are now up to speed.
> > >>>>>
> > >>>>> ---Steve Martin as Inspector Clouseau
> > >>>>> ? Pink Panther 2
> > >>>>>
> > >>>> _______________________________________________
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> > >>>>
> > >>
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> > >>
> > >>
> > >> --
> > >>
> > >> Bryan G. Seitz
> > >>
> > > _______________________________________________
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> 
> -- 
> Your life is like a penny.  You're going to lose it.  The question is:
> How do
> you spend it?
> 
>          John Covici
>          covici@ccs.covici.com
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-- 
             
Bryan G. Seitz



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