In your case it seems reasonable, but you should test the 2 stripe sizes (128K vs 256K) before running in production. The good thing about replica volumes is that you can remove a brick , recreate it from cli and then add it back.
Best Regards,
Strahil Nikolov
В сряда, 30 септември 2020 г., 17:03:11 Гринуич+3, C Williams <cwilliams3320@gmail.com> написа:
Hello,
I am planning to use (6) 1 TB disks in a hardware RAID 6 array which will yield 4 data disks per oVirt Gluster brick.
However. https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.5/html-single/administration_guide/index#sect-Disk_Configuration --- states
"For RAID 6, the stripe unit size must be chosen such that the full stripe size (stripe unit * number of data disks) is between 1 MiB and 2 MiB, preferably in the lower end of the range. Hardware RAID controllers usually allow stripe unit sizes that are a power of 2. For RAID 6 with 12 disks (10 data disks), the recommended stripe unit size is 128KiB"
In my case, each oVirt Gluster Brick would have 4 data disks which would mean a 256K hardware RAID stripe size ( by what I see above) to get the full stripe size unit to above 1 MiB ( 4 data disks X 256K Hardware RAID stripe = 1024 K )
Could I use a smaller stripe size ex. 128K -- since most of the oVirt virtual disk traffic will be small sharded files and a 256K stripe would seem to me to be pretty big.for this type of data ?
Thanks For Your Help !!
On Tue, Sep 29, 2020 at 8:22 PM C Williams <cwilliams3320@gmail.com> wrote:
> Strahil,
>
> Once Again Thank You For Your Help !
>
> On Tue, Sep 29, 2020 at 11:29 AM Strahil Nikolov <hunter86_bg@yahoo.com> wrote:
>> One important step is to align the XFS to the stripe size * stripe width. Don't miss it or you might have issues.
>>
>> Details can be found at: https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.5/html-single/administration_guide/index#sect-Disk_Configuration
>>
>> Best Regards,
>> Strahil Nikolov
>>
>>
>>
>>
>>
>>
>> В вторник, 29 септември 2020 г., 16:36:10 Гринуич+3, C Williams <cwilliams3320@gmail.com> написа:
>>
>>
>>
>>
>>
>> Hello,
>>
>> We have decided to get a 6th server for the install. I hope to set up a 2x3 Distributed replica 3 .
>>
>> So we are not going to worry about the "5 server" situation.
>>
>> Thank You All For Your Help !!
>>
>> On Mon, Sep 28, 2020 at 5:53 PM C Williams <cwilliams3320@gmail.com> wrote:
>>> Hello,
>>>
>>> More questions on this -- since I have 5 servers . Could the following work ? Each server has (1) 3TB RAID 6 partition that I want to use for contiguous storage.
>>>
>>> Mountpoint for RAID 6 partition (3TB) /brick
>>>
>>> Server A: VOL1 - Brick 1 directory /brick/brick1 (VOL1 Data brick)
>>> Server B: VOL1 - Brick 2 + VOL2 - Brick 3 directory /brick/brick2 (VOL1 Data brick) /brick/brick3 (VOL2 Arbitrator brick)
>>> Server C: VOL1 - Brick 3 directory /brick/brick3 (VOL1 Data brick)
>>> Server D: VOL2 - Brick 1 directory /brick/brick1 (VOL2 Data brick)
>>> Server E VOL2 - Brick 2 directory /brick/brick2 (VOL2 Data brick)
>>>
>>> Questions about this configuration
>>> 1. Is it safe to use a mount point 2 times ? https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.3/html/administration_guide/formatting_and_mounting_bricks#idm139907083110432 says "Ensure that no more than one brick is created from a single mount." In my example I have VOL1 and VOL2 sharing the mountpoint /brick on Server B
>>>
>>> 2. Could I start a standard replica3 (VOL1) with 3 data bricks and add 2 additional data bricks plus 1 arbitrator brick (VOL2) to create a distributed-replicate cluster providing ~6TB of contiguous storage ? .
>>> By contiguous storage I mean that df -h would show ~6 TB disk space.
>>>
>>> Thank You For Your Help !!
>>>
>>> On Mon, Sep 28, 2020 at 4:04 PM C Williams <cwilliams3320@gmail.com> wrote:
>>>> Strahil,
>>>>
>>>> Thank You For Your Help !
>>>>
>>>> On Mon, Sep 28, 2020 at 4:01 PM Strahil Nikolov <hunter86_bg@yahoo.com> wrote:
>>>>> You can setup your bricks in such way , that each host has at least 1 brick.
>>>>> For example:
>>>>> Server A: VOL1 - Brick 1
>>>>> Server B: VOL1 - Brick 2 + VOL 3 - Brick 3
>>>>> Server C: VOL1 - Brick 3 + VOL 2 - Brick 2
>>>>> Server D: VOL2 - brick 1
>>>>>
>>>>> The most optimal is to find a small system/VM for being an arbiter and having a 'replica 3 arbiter 1' volume.
>>>>>
>>>>> Best Regards,
>>>>> Strahil Nikolov
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> В понеделник, 28 септември 2020 г., 20:46:16 Гринуич+3, Jayme <jaymef@gmail.com> написа:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> It might be possible to do something similar as described in the documentation here: https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.4/html/administration_guide/creating_arbitrated_replicated_volumes#sect-Create_Multiple_Arbitrated_Volumes -- but I'm not sure if oVirt HCI would support it. You might have to roll out your own GlusterFS storage solution. Someone with more Gluster/HCI knowledge might know better.
>>>>>
>>>>> On Mon, Sep 28, 2020 at 1:26 PM C Williams <cwilliams3320@gmail.com> wrote:
>>>>>> Jayme,
>>>>>>
>>>>>> Thank for getting back with me !
>>>>>>
>>>>>> If I wanted to be wasteful with storage, could I start with an initial replica 2 + arbiter and then add 2 bricks to the volume ? Could the arbiter solve split-brains for 4 bricks ?
>>>>>>
>>>>>> Thank You For Your Help !
>>>>>>
>>>>>> On Mon, Sep 28, 2020 at 12:05 PM Jayme <jaymef@gmail.com> wrote:
>>>>>>> You can only do HCI in multiple's of 3. You could do a 3 server HCI setup and add the other two servers as compute nodes or you could add a 6th server and expand HCI across all 6
>>>>>>>
>>>>>>> On Mon, Sep 28, 2020 at 12:28 PM C Williams <cwilliams3320@gmail.com> wrote:
>>>>>>>> Hello,
>>>>>>>>
>>>>>>>> We recently received 5 servers. All have about 3 TB of storage.
>>>>>>>>
>>>>>>>> I want to deploy an oVirt HCI using as much of my storage and compute resources as possible.
>>>>>>>>
>>>>>>>> Would oVirt support a "replica 5" HCI (Compute/Gluster) cluster ?
>>>>>>>>
>>>>>>>> I have deployed replica 3s and know about replica 2 + arbiter -- but an arbiter would not be applicable here -- since I have equal storage on all of the planned bricks.
>>>>>>>>
>>>>>>>> Thank You For Your Help !!
>>>>>>>>
>>>>>>>> C Williams
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>>>>>>>
>>>>>>
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>>>>
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