[ale] ISCSI array on virtual machine

DJ-Pfulio DJPfulio at jdpfu.com
Wed Apr 27 22:50:35 EDT 2016


rdiff-backup is like rsync, but with versioning.
Most recent backup is just like an rsync mirror.  30 days of backups is
1.10x the original size here. YMMV.

He has 8T (or was that a typo?). Partitioned/LV'd into smaller chunks (I
assume).

Shrinking is common around here, which keeps me away from xfs.
Different use-cases and comforts, I suppose. Is XFS well supported by
Ubuntu? I don't recall.  I know the RHEL guys love it, but what about
Ubuntu which **is** the OS being used?


On 04/27/16 16:15, Todor Fassl wrote:
> I intend to use the old ISCSI array to backup the new one.  Actually
> both the old and new arrays are only about 50% user space. VMware has
> the other 50%. But we'll move all the VMware data stores to the new
> array and then use the entire old array as a backup. What I do is to use
> rsync to backup one array to the other one and then use amanda to make a
> backup of the backup  on virtual tapes in another building.  If someone
> wants me to undelete a file, I just copy it backfrom the old ISCSI
> array. If they want something put back the way it was last week, I have
> to go to the vtapes.
> 
> On 04/27/2016 02:19 PM, DJ-Pfulio wrote:
>> a) I always use LVM on block storage.  Resizing up/down is trivial,
>> provided you don't use xfs. Doesn't sound like you **need** xfs, so I'd
>> go with ext4. If they are doing RAID6, that means the primary reason I'd
>> use ZFS is removed.  There are other reasons for ZFS, but you really
>> need to HAVE A REASON to use it, IMHO. The built-in CIFS server can be
>> nice, but that wouldn't be enough reason for me. ;)
>>
>> b) LV sizes are set based on what is easy to backup.  4T is the backup
>> size limit here, so no LV is over about 3.5T in size. You might have
>> similar drivers or not.
>>
>> I wouldn't be afraid of ZFS on Ubuntu x64. The x32 stuff, was always
>> scary to me.
>>
>> On 04/27/16 14:54, Todor Fassl wrote:
>>> I need to setup a new file server on a virtual machine with an attached
>>> ISCSI array. Two things I am obsessing over -- 1. Which file system to
>>> use and 2. Partitioning scheme.
>>>
>>> The ISCSI array is attached to a ubuntu 16.04 virtual machine. To tell
>>> you the truth, I don't even know how that is done. I do not manage the
>>> VMware cluster.  In fact, I think the Dell technitian actually ddid that
>>> for us. It looks like a normal 8T hard drive on /dev/sdb to the virtual
>>> machine. The ISCSI array is configured for RAID6 so from what I
>>> understand, all I have to do is choose a file system appropriate for my
>>> end user's needs. Even though the array looks like a single hard drive,
>>> I don't have to worry about software RAID or anyhthing like that.
>>>
>>> Googling shows me no clear advantage to ext4, xfs, or zfs. I haven't
>>> been able to find a page that says any one of those is an obvious choice
>>> in my situation. I have about 150 end-users with nfs mounted home
>>> directories. We also have a handful of people using Windows so the file
>>> server will have samba installed. It's a pretty good mix of large files
>>> and small files since different users are doing drastically different
>>> things. There are users who never do anything but read email and browse
>>> the web and others doing fluid dynamic simulations on small
>>> supercomputers.
>>>
>>> Secondthing I've been going back and forth on in my own mind is whether
>>> to do away with seperate partitions for faculty, staff, and grad
>>> students. My co-worker says that's probably an artifact of the days when
>>> partition sizes were limited. That was before my time here. The last 2
>>> times we rebuilt our file server, we just maintained the partitioning
>>> scheme and just made the sizes  times larger. But sometimes the faculty
>>> partition got filled up while there was still plenty of space left on
>>> the grad partition. Or it might be the other way around. If we munged
>>> them all together, that wouldn't happen. The only downside I see to
>>> doing that is that if the faculty partition gets hosed, the grad
>>> partition wouldn't be effected. But that seems like a pretty arbitrary
>>> choice. We could just assign users randomly to one partition or another.
>>> When you're setting up a NAS for use by a lot of users, is it considered
>>> best practice to split it up to limit the damage from a messed up file
>>> system? I mean, hopefully, that never happens anyway, right?
>>>
>>> Right now, I've got it configured as one gigantic 8T ext4 partition. But
>>> we won't be going live with it until the end of May so I have plenty of
>>> time to completely rebuild it.
>>>
>>
>>
> 


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