Re: [vserver] NFS shares or iSCSI

From: Herbert Poetzl <herbert_at_13thfloor.at>
Date: Mon 12 Dec 2011 - 13:23:39 GMT
Message-ID: <20111212132339.GL6554@MAIL.13thfloor.at>

On Mon, Dec 12, 2011 at 02:03:13PM +0100, Eugen Leitl wrote:
> On Mon, Dec 12, 2011 at 01:55:45PM +0100, Herbert Poetzl wrote:
>> On Mon, Dec 12, 2011 at 12:47:55PM +0100, Eugen Leitl wrote:

>>> I would like to put a zfs hybrid box I have for vserver
>>> production, to improve IOPS of the underlying disks.

>> so some kind of raid/pool setup with ssd/memory caches
>> or something like that?

> Yeah, it's an 8 GByte RAM 4x 1 TByte Solaris box
> with an Intel SSD cache.

>>> 1) would you use iSCSI or NFS for vserver guests, for
>>> better performance and/or flexibility?

>> iSCSI will result in 'block' transfers (similar goes for
>> AOE) so that requires a filesystem on the client with all
>> the filesystem overhead, but it might provide better
>> performance for 'certain' workloads

> Which workloads in particular? I'm worried about
> workloads like IMAP with Maildir. If thens or
> hundreds vserver guests are running on a single
> machine there bound to be several users fighting
> for spindle access at the same time.

>>> 2) is just mounting /home e.g. via NFS for each
>>> vserver guest a better idea?

>> than having the entire guest on NFS?

> Yes.

>> also, the 'zfs hybrid box' is a different machine than
>> the one running the guests?

> Yes. Connected via GBit Ethernet. I can enable jumbo
> frames.

so, what performance do you get over this setup
ignoring any filesystem overhead? 50MB/s 100MB/s ?
how many packets (I/O operations) can you transmit
in a second? 10k? 20k? ...

I guess a single SSD, attached via SATA 6GB locally
will seriously outperform whatever solution you have
in mind, but of course, you cannot share that between
different hosts easily

best,
Herbert

>> please clarify the setup, otherwise it's mostly hand
>> waving and probably useless for your setup

> Thanks, the questions you've asked are helping me already.

> --
> Eugen* Leitl leitl http://leitl.org
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Received on Mon Dec 12 13:23:49 2011

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