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We run a couple of XIV's - they seem ok so far. Pretty easy to admin but not much to be able to user tune the performance (IBM claim this isn't needed however ! )
They havn't failed yet so I can't comment on the reliability.
Thanks for the feedback Chris. There just isn't a lot of customer/user feedback out there on this platform. If you know of any good sources - please send them my way. Take care and thanks again!
We're running about 215 VMs on 16 hosts on an XIV. This includes something like 85% of our Tier 1 apps, including all of Exchange 2007, sales systems, heavy SQL databases, etc. I'm not the storage guy, so I can't really speak to the administration side of it (I've been told, though, that it's imensely easy, almost a non-event). But I can tell you that the performance is extremely good. Our slowest datastore showed a latency of < 1 ms a couple of weeks ago. So we have no complaints at all from a performance level. The cost is good as well. In the 9 months or so since we've had it, we've lost around 3 or 4 drives. There are basically no tools for the XIV, though, which is our biggest complaint. We're told they'll start coming out at the beginning of the year, though. I can't wait for some of the storage migration pieces to come out.
When we researched the XIV last fall, we found virtually nothing at all about it. That didn't help us feel very confident. However, so far it's proving itself. Give us some tools (vStorage APIs) and we'd be very happy with the box.
I have a customer that is using one of these IBM SAN's with SATA storage - i have been told this is not a performance issue as the data is primarily held in memory - is this statement correct.
I don't know if that's true or not (I'm not the storage guy). I don't believe so, though. I believe that they're able to achieve high performance by running over 180 spindles over 15 servers with three of them serving as heads/supervisors. Unfortunately, I don't know enough about how the XIV works to tell you.
We're currently running approx 400VM's, over 20 hosts, as well as a host of other P-Series and dedicated servers all attached to 4 x XIV arrays and no complaints here; simple to manage, simple to expand, simple to provision, more than reasonable performance.
I think this type of storage is an adminstrators dream as there is no tuning required, no hot spots can occur and there is no disk layout design required upfront, it's pretty much plug and play which for this type of storage is amazing. It has detailed reports built into the GUI which can individual volume performance to help diagnose any potential performance issues, which will usually be the SAN Fabric or the Hosts themselves and not XIV.
In terms of resilience, another 2 thumbs up. Each array has 3 x UPS within the rack, unfortunely one of ours was damaged during installation so we only had 2 operational for short while and wouldn't you know it, we had a major power failure in the dataroom, but XIV stayed up and we had no storage issues at all once power was restored and the hosts came back online. Disk failure rates also seem pretty low; the IBM salesman will tell you this is because of all the disks being used and running at consistent speeds and not being thrashed as can happen in more traditional arrays, I don't know if this is true but I do know that when we do have a disk failure an IBM engineer turns up the next day to replace it without us doing anything....
People tend to get scared of XIV because of the SATA drives but I always explain that XIV isn't meant to provide jaw dropping performance, it's supposed to provide good performance in a nice, easy to manage, easy to grow, single rack based solution that is competetively priced and I think it does exactly what it says on the tin....
The only thing I would be slightly careful of is that you'll only ever get the best performance out of a fully loaded XIV unit (all 15 modules), if you have a partial array you obviously have less spindles and less cache to utilise.
FYI - I don't work for IBM, I work for a large outsourcer who is very happy with XIV...
Thanks for the update - some really interesting info.
When i heard this was SATA storage my concerns were around performance and reliability - someone suggested to me that performance was maintained by having lots of cache - so the data was retreived from the cache rather than the disks -is this statement correct from your experience of this storage.
yeah, I think it's probably fair to say that XIV relies on 3 key elements to provide the performance from what are effecitevly slow SATA drives:
1 - large numbers of spindles behind each block of data. Everything within XIV is split into 1gb chunks and spread over every single disk in the entire array. In a fully loaded XIV there are 160 spindles, which in my opinion is a lot, and more than compensates for the slower speed of SATA compared to faster FC disks
2 - large amounts of cache; a fully loaded XIV currently has 120gb (and upto 21 CPU's), which again is quite a considerable amount compared to more traditional arrays and I'm sure these numbers will rise over time as the technology continues to evolve as it utilises standard components so, for example, the move to quad, hex or oct core processors should be relatively quick
3 - concurrent processing; not only is all of the data within XIV spread over every disk spindle, there is also a large amount of I/O connectivity provided by the 6 Data Modules (there are 24 4gb FC ports, 12 of which are used for hosts, the rest are for mirroring and data migrations) which, with clever zoning, can ensure the heavier host servers get lots of potential bandwidth.
Another thing that worries people about XIV is it's still 4gb based architecture but I don't see any real issues with this at the moment due to it having lots of concurrent bandwidth, and I'm sure 8gb can't be that far away.
Reliablity also isn't an issue, in my experience. Over the past 12 months we've probably had approx 1 disk failure a month across the 4 arrays, which out of 640 disks I don't think is too bad. The rebuild times for failed disks is also very quick, it takes a maximum of 30minutes to rebuild a failed disk which means the data is very quickly re-protected. Other than the DOA UPS mentioned in my ealier post, to date we've not had any other type of component failures within the XIV arrays so I can't comment on how well they continue to operate when something major does fail but they are supposed to be fully N+1.
I can also confirm that firmware upgrades are non-disruptive.
5 PowerEdge M610's Hosts in a Dell M1000e chassis
8 CPU x 2.659 GHz
Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
47.99 GB RAM
Datastores are LUN's on an EMC Clariion
I'm currently in the planning phase of migrating from an EMC Clariion SAN to two XIV's (one for prod, the other for the DR site). Things are going okay and I'll try to update this thread as the process goes on.
Our XIV prod rack will have all bays filled with 1TB drives (I wanted the 2TB, trust me) and the DR site will be a half-height with 2TB drives.
In addition, we are also buying into an nSeries NetApp and I'm not exactly 100% certain how this works as I was just brought onboard around a week ago. I plan on going to the nSeries classes and getting some official training but I've heard that the XIV is VERY easy to use and I can't wait to see the interface. From what I've heard so far the nSeries will host all of our shares from our file servers using the XIV and we'll only really use the XIV for our Unix environment(?).
There's still a lot to be worked out and I'm learning about this company at a break neak pace so I'm sure things will become clearer as time goes on. I'll be sure to update this post.
Message was edited by: legisilver 01.26.2011
Do you use a centrel backup solotion with XIV like netapp with smvi or do you use a backup client in every vm?
Recently migrated 3 host vSphere cluster, AIX and Windows storage to an XIV, w/ 2Tb drives, from an older IBM storage array ... very please so far.
a: migration tools were amazing, AIX and Windows hosts (2Tb+) moved with very little host downtime. data copies from old storage to XIV, out of band to the host, while the host is happily back in production on XIV. VMware storage vmotion used for VMs .. zero downtime
b. XIV gui is hugely advanced from my old storage server interface
c. Storage changes and snapshots are virtually instantaneous
d. Thin provisioned luns and snapshots ... yeah
e. XIV gui realtime and historical performance data granualarity IOPS/Latency by interface, lun or host
f. xCLI ... yeah
g. performance is very good ..... sub ms latency
h. reliability ... no downtime to date / no single point of failure that I'm aware of
Wish list: a script that snapshots my critical VMs, initiates XIV snapshot and cleans up/deletes those VMs snapshots
The IBM guys are talking about a migration utility that will move the LUN's. Did you use this?
You mean SVC to perform the LUN migration?