Re: v-slow raid resync

I'll wager its mostly due to not needing to resize and re-parity one drive.

On 20/03/14 10:58, Jeff Allison wrote:
> I failed the suspect disk out of the array and now the rebuild is
> 16000K/sec 4x faster.
>
> Strange.
>
> Time to do some disk testing...
>
> On 19 March 2014 14:59, Jeff Allison <[email protected]> wrote:
>> I ran hdparm...
>>
>> [root@nas ~]# hdparm -tT /dev/sdd <-- dud disk
>>
>> /dev/sdd:
>>   Timing cached reads:   2318 MB in  2.00 seconds = 1158.86 MB/sec
>>   Timing buffered disk reads:   2 MB in 25.35 seconds =  80.79 kB/sec
>>
>> [root@nas ~]# hdparm -tT /dev/sdc <-- good disk
>>
>> /dev/sdc:
>>   Timing cached reads:   2470 MB in  2.00 seconds = 1234.85 MB/sec
>>   Timing buffered disk reads: 296 MB in  3.01 seconds =  98.35 MB/sec
>>
>> Not much in it.
>>
>> On 19 March 2014 14:23, Jeff Allison <[email protected]> wrote:
>>> The disk sector sizes are the same on all the disks.
>>>
>>> Logical  Sector size:                   512 bytes
>>> Physical Sector size:                  4096 bytes
>>>
>>> Is chunk size stripe size?
>>>
>>> [root@nas ~]# mdadm --detail /dev/md0
>>> /dev/md0:
>>>          Version : 1.2
>>>    Creation Time : Fri Feb 21 09:33:55 2014
>>>       Raid Level : raid5
>>>       Array Size : 3905985536 (3725.04 GiB 3999.73 GB)
>>>    Used Dev Size : 1952992768 (1862.52 GiB 1999.86 GB)
>>>     Raid Devices : 4
>>>    Total Devices : 4
>>>      Persistence : Superblock is persistent
>>>
>>>      Update Time : Wed Mar 19 14:22:35 2014
>>>            State : clean, reshaping
>>>   Active Devices : 4
>>> Working Devices : 4
>>>   Failed Devices : 0
>>>    Spare Devices : 0
>>>
>>>           Layout : left-symmetric
>>>       Chunk Size : 512K
>>>
>>>   Reshape Status : 28% complete
>>>    Delta Devices : 1, (3->4)
>>>
>>>             Name : nas.allygray.2y.net:0  (local to host nas.allygray.2y.net)
>>>             UUID : 1a122cbe:ada65085:680e451c:180c7689
>>>           Events : 21723
>>>
>>>      Number   Major   Minor   RaidDevice State
>>>         0       8       17        0      active sync   /dev/sdb1
>>>         1       8       33        1      active sync   /dev/sdc1
>>>         3       8        1        2      active sync   /dev/sda1
>>>         4       8       49        3      active sync   /dev/sdd1
>>>
>>> When I created the partitions I used the -a optimal which I thought sorted that?
>>>
>>> On 19 March 2014 14:11, Jake Anderson <[email protected]> wrote:
>>>> its probably *madly* seeking which is why its so slow.
>>>> I wonder, what is the block size you are using on the disk and the stripe
>>>> size of your array?
>>>>
>>>> If you are read modify writing a 4K disk in 512k blocks it'll be dog slow.
>>>>
>>>> On 19/03/14 14:00, Jeff Allison wrote:
>>>>> The thing I find strange is that in iostat the disk shows as 100% at 3/4
>>>>> MB/s.
>>>>>
>>>>> I wonder how iostat decides on the percent?
>>>>>
>>>>> On 19 March 2014 10:53, Jake Anderson <[email protected]> wrote:
>>>>>> This isn't going to be an issue with sata vs whatever (though I do
>>>>>> suggest
>>>>>> running in ahci mode if thats an option)
>>>>>>
>>>>>> The issue is probably going to be how mdadm is growing the array, it will
>>>>>> need to do a buttload of disk access to do that reading and writing every
>>>>>> sector on every disk and trying to keep everything in a consistent state
>>>>>> while doing so.
>>>>>>
>>>>>> I don't know if it applies to whatever raid level you are using but is
>>>>>> there
>>>>>> something like an --assume-clean option you can pass it?
>>>>>> I'd also suggest asking in the mdadm list or perhaps IRC.
>>>>>> http://forums.whirlpool.net.au/archive/1056831 might be of interest.
>>>>>>
>>>>>>
>>>>>> On 18/03/14 20:02, Rachel Polanskis wrote:
>>>>>>> On 18 Mar 2014, at 6:46 pm, Jeff Allison <[email protected]>
>>>>>>> wrote:
>>>>>>>
>>>>>>> That's installed unfortunately didn't fix my problem. How badly
>>>>>>> configured
>>>>>>> does a disk need to be to only run at 4mb
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> Sorry for the suck eggs question, but you did enable all the features in
>>>>>>> the BIOS e.g. turning on SATA II 3gbps support,
>>>>>>> write cache disable etc?   In the URL link to the forum below they
>>>>>>> discuss
>>>>>>> all the optimum settings.  I am using
>>>>>>> WD RED NAS drives (2x2tb) and Seagate 3Tb drives (latest model) in my
>>>>>>> system so similar to yours....
>>>>>>>
>>>>>>> rachel
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On 18/03/2014 3:43 PM, "Rachel Polanskis" <[email protected]> wrote:
>>>>>>> On 18 Mar 2014, at 3:14 pm, Jeff Allison <[email protected]>
>>>>>>> wrote:
>>>>>>>
>>>>>>> Is it the O41072911.ROM?
>>>>>>>
>>>>>>> Did you use flashrom of the dos disk thingo.
>>>>>>>
>>>>>>> On 18 March 2014 14:06, gr0ve <[email protected]> wrote:
>>>>>>>> Seriously, you should flash the BIOS!  I get 80mbps reads on ZFS
>>>>>>>> and depending, 30-40mbps on writes.  Without the BIOS mod, you
>>>>>>>> are getting only IDE speeds there.  The original BIOS holds this
>>>>>>>> machine
>>>>>>>> back and it is perfectly safe.  The BIOS ensures AHCI support is
>>>>>>>> operational
>>>>>>>> as well as the 3gbps SATA II bus. Once you see the improvement, you
>>>>>>>> can choose to also select write cache enabled|disabled although
>>>>>>>> this is best with a UPS ;)
>>>>>>>>
>>>>>>>>
>>>>>>>> rachel
>>>>>>> Hi,
>>>>>>> The HP BIOS version is the O41072911.ROM as you suggest.
>>>>>>> You need this to install the "theBay" ROM as well.
>>>>>>>
>>>>>>> The process is shown online, but in short you copy the HP BIOS using a
>>>>>>> DOS/windows installer to a USB stick then copy the "theBay" rom image
>>>>>>> over
>>>>>>> the
>>>>>>> top. You could try to "dd" the image but it does some weird trickery to
>>>>>>> make
>>>>>>> the stick bootable for installing the BIOS.
>>>>>>>
>>>>>>> You can look for TheBay_Microserver_Bios_041.rar online.
>>>>>>> The source information is:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> http://www.avforums.com/threads/hp-n36l-n40l-n54l-microserver-updated-ahci-bios-support.1521657/
>>>>>>>
>>>>>>> And it has all the guff on getting the BIOS onto your N54L and also tips
>>>>>>> on how to configure it.
>>>>>>> I have all the files if you need them....
>>>>>>>
>>>>>>> Once again, these are terrific little servers.  It has an internal USB
>>>>>>> port so I just loaded FreeNAS
>>>>>>> onto an 8Gb USB stick and boot from there.  All the internal SATA disks
>>>>>>> are in ZFS disk pools which
>>>>>>> do my bidding. As I use ZFS, I went with 8gb ECC memory. I also added an
>>>>>>> additional Gigabit Ethernet adaptor as the built in broadcom is general
>>>>>>> networking and I run the second Gig-E port with Jumbo Frames using a
>>>>>>> gigabit
>>>>>>> crossover (there is such a thing)
>>>>>>> to a Mac Mini with the thunderbolt port running Gig-E and doing iSCSI!
>>>>>>> The Mac Mini runs esxi 5.5 and
>>>>>>> all the data stores (running various species of Linux) hosted off the
>>>>>>> HP-N54L.  It is like a little tiny
>>>>>>> SAN, small but perfectly formed....
>>>>>>>
>>>>>>>
>>>>>>> rachel
>>>>>>>
>>>>>>> --
>>>>>>> Rachel Polanskis                 Kingswood, Greater Western Sydney,
>>>>>>> Australia
>>>>>>> [email protected]             IT consulting, security, programming
>>>>>>>            The more an answer costs, the more respect it carries.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Rachel Polanskis                 Kingswood, Greater Western Sydney,
>>>>>>> Australia
>>>>>>> [email protected]             IT consulting, security, programming
>>>>>>>           The more an answer costs, the more respect it carries.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> --
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>>>>>> Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
>>>>

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