[cisco-voip] UCS C210 Replace 146 GB Disk in RAID5 with 300 GB Disk

Sun Nov 19 13:16:57 EST 2017

Hallo

Thanks for your feedbacks.
I got a 300 GB replacement disk from Cisco. I changed the disks in the
Server, but the new (300GB) shoes as failed in CMIC.
I am waiting for a replacement from the support.

Regards Reto

Lelio Fulgenzi <lelio at uoguelph.ca> schrieb am Mi. 15. Nov. 2017 um 17:15:

> Thanks for laying it out Ryan.
>
>
>
>
>
> *From:* Ryan Ratliff (rratliff) [mailto:rratliff at cisco.com]
> *Sent:* Wednesday, November 15, 2017 10:57 AM
> *To:* Lelio Fulgenzi <lelio at uoguelph.ca>
> *Cc:* Charles Goldsmith <wokka at justfamily.org>; cisco-voip list <
> cisco-voip at puck.nether.net>
>
>
> *Subject:* Re: [cisco-voip] UCS C210 Replace 146 GB Disk in RAID5 with
> 300 GB Disk
>
>
>
> The 4 arrays on BE7K also have an impact on IOPS for the volume, though
> the servers are primarily built that way for array rebuild times as has
> been noted previously in this thread.
>
>
>
> On that server especially while one volume may be fine from a space
> perspective note that the amount of IOPS for DAS is derived from the number
> of disk spindles in the array.
>
> This means it is entirely possible to cause IO starvation problems on a
> BE7K by putting all the VMs on a single storage volume.
>
> Spreading your VMs across the arrays will provide you protection against
> multiple disk failures (because they are RAID 5) AND spread the IOPS load
> across them.
>
>
>
> With respect to rebuilding a TRC’s RAID5 into RAID6 or RAID10 that server
> is no longer classified as a TRC and thus Cisco cannot guarantee the same
> level of performance we would otherwise.
>
> You may be perfectly comfortable with making such a change and willing to
> take on the risk, but guaranteeing the server meets the IOPS requirements
> of the apps running on it is your responsibility, not ours.
>
>
>
> If things go sideways you can expect TAC to ask you to rebuild it to a
> RAID5 (or at least one volume) the way it shipped as part of the
> troubleshooting process.
>
>
>
> -Ryan
>
>
>
> On Nov 14, 2017, at 11:33 AM, Lelio Fulgenzi <lelio at uoguelph.ca> wrote:
>
>
>
> Yeah, I hear ya. I mean, it’s not like there are not advantages, but,
> still, the managing of which array to put things in. ugh.
>
>
>
>
>
> *From:* Charles Goldsmith [mailto:wokka at justfamily.org
> <wokka at justfamily.org>]
> *Sent:* Tuesday, November 14, 2017 10:48 AM
> *To:* Lelio Fulgenzi <lelio at uoguelph.ca>
> *Cc:* Ryan Huff <ryanhuff at outlook.com>; cisco-voip at puck.nether.net
> *Subject:* Re: [cisco-voip] UCS C210 Replace 146 GB Disk in RAID5 with
> 300 GB Disk
>
>
>
> Lelio, if you are using those be7k's for UC apps, your limiting factor is
> always the CPU cores, you won't run out of drive space.  Also, the be7K-h
> is a workhorse of a server, fastest one I've ever built a cluster on.  4
> independent arrays means you can easily do maintenance on one app without
> affecting the performance of another, assuming you separate your apps
> between arrays and stagger them out.  I did 4 simultaneous installs on one,
> each app on it's own partition and they were all done in under 2 hours.
>
>
>
> Sadly, the pricepoint on the H isn't there for most customers.  the M is
> nice, but only has 2 of the arrays, but I'll take an H for an install any
> day!
>
>
>
> On Tue, Nov 14, 2017 at 9:34 AM, Lelio Fulgenzi <lelio at uoguelph.ca> wrote:
>
>
>
> The idea of RAID drives and managing the different volumes always had me
> on the fence on how to do things. In a perfect world, I’d stick with one
> big RAID 6 array with a spare on the shelf.
>
>
>
> The BE7K servers I ordered were delivered with 4 RAID 5 arrays.
> Personally, while I can appreciate separating the arrays, I don’t like
> losing that extra space and managing which volume to put images on is a
> pain.
>
>
>
> I’ll admit, I looked at RAID 10 (when I was first reading the TRC specs)
> and was confused to heck. I did finally understand things after referring
> to a colleague, but it was a lot of drawing out.
>
>
>
> I will say this, RAID isn’t gonna protect you if you don’t have platform
> monitoring on. You need to know the second a drive fails so you can proceed
> accordingly.
>
>
>
> Also, if the ever do construction in your computer room, do yourself a
> favour, go to the hardware store, buy a 9.99 loose fibre furnace filter and
> stick it in front of your air intakes.
>
>
>
>
>
>
>
> *From:* cisco-voip [mailto:cisco-voip-bounces at puck.nether.net] *On Behalf
> Of *Charles Goldsmith
> *Sent:* Tuesday, November 14, 2017 9:48 AM
> *To:* Ryan Huff <ryanhuff at outlook.com>
> *Cc:* cisco-voip at puck.nether.net
> *Subject:* Re: [cisco-voip] UCS C210 Replace 146 GB Disk in RAID5 with
> 300 GB Disk
>
>
>
> I've seen one URE fail in a raid 5 resilvering process, years ago on a DG
> system.  Had to rebuild and restore from backup, fun times.
>
>
>
> I agree Ryan, on a TRC system and RMA a drive, you stick with it.
>
>
>
> From my reading on TRC, you can rebuild as a RAID 10 and get faster
> speeds, but you lose some space in the process.
>
>
>
> On my personal systems, I'm using RAID 10 everywhere.
>
>
>
> On Tue, Nov 14, 2017 at 8:17 AM, Ryan Huff <ryanhuff at outlook.com> wrote:
>
> As I’ve read and understood; it isn’t due to actual functionality though.
> It is as you say, due mostly to longer rebuild times (indexing a physically
> larger geometry than the rest of the array members, for a smaller logical
> geometry) and the risk (rare IMO) to the rest of the array (as a rebuild
> will stress the array and could cause other, near-death disks to fail
> thereby causing the array to fail). It also wastes the extra horsepower of
> the disk since the existing RAID can’t capitalize on the resources of the
> larger disk.
>
>
>
> So in a case of, would you go out and buy a new disk that way .... I’d say
> no; but if that is the result of a covered RMA, I’d say go for it.
>
>
>
> I’m no diskologist though ... just based on my own experiences of what has
> worked for me for the last couple of decades ... and I’ve never lost a
> server ... outside of that one time when my pants pocket snagged the
> release on the 2nd disk in a R5 on my way out the door ... bad memories.
>
> -Ryan
>
>
> On Nov 14, 2017, at 9:03 AM, Charles Goldsmith <wokka at justfamily.org>
> wrote:
>
> Keep in mind, RAID 5 is ok for smaller disks, but larger disks it's no
> longer recommended, but sadly, the best article about it is from Dell:
> http://en.community.dell.com/techcenter/b/techcenter/archive/2012/08/14/new-equallogic-raid-tech-report-considerations-and-best-practices-released
>
>
>
> With bigger disks, it's even said that RAID 6 is no longer good enough,
> due to large rebuild times in case of a failure.
> http://www.zdnet.com/blog/storage/why-raid-6-stops-working-in-2019/805
>
>
>
> On Tue, Nov 14, 2017 at 7:41 AM, Ryan Huff <ryanhuff at outlook.com> wrote:
>
> Reto,
>
> Seek/rpm speeds and media type (flash, sata ... etc) are usually what
> matter the most for RAID disks. If your only difference is total storage
> capacity, the bigger disk will usually work just fine, your just gonna
> waste the additional 154GB of space (because the RAID will only provision
> 146GB of that 300GB disk).
>
>
>
> Just remember on a RAID 5, don’t pull/lose more that 1 disk at a time ....
> painful lesson long ago I share over beer every now and then.
>
>
>
> -Ryan
>
>
> On Nov 14, 2017, at 8:23 AM, Reto Gassmann <voip at mrga.ch> wrote:
>
> Hallo
>
>
>
> We have a UCS C210 Server with 10x146 GB Disks. One of the Disks failed
> and I got a 300 GB replacement Disk from Cisco.
>
>
>
> Is that a problem if I replace the defect 146 Disk in the RAID 5 with a
> 300 GB Disk?
>
>
>
> Thanks for help
>
> Regards Reto
>
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