HPE Smart Storage Battery for HPE Smart Array P440/4G Controller.

[parnassus]

Hello all,

In reading the latest HPE Smart Array P440 Controller QuickSpecs (August 2016, here) I noticed that the HPE Smart Array P440/4G Controller option kit (726821-B21) - with respect to the other possible HPE Smart Array P440/2G Controller option kit (820834-B21) - doesn't include the HPE Smart Storage Battery (727258-B21) which acts as the backup power source necessary to protect the Controller data on its Flash-backed Write Cache).

A note in that QuickSpecs says:

"HPE Smart Array P440/4GB FBWC controller option kit does not include the HPE Smart Storage Battery the backup power source necessary to protect the data on the Flash-backed Write Cache. HPE Smart Storage Battery is an item that has to be purchased separately if this is the first P-series Smart Array controller on your Gen9 server."

My question is about sentencing: that "...is an item that has to be purchased if..." means that the presence of the HPE Smart Storage Battery is mandatory for the (first/single) HPE Smart Array P440/4G Controller option kit (726821-B21) to work or just that it's only highly recommended but not mandatory?

In other terms: Can the HPE Smart Array P440/4G Controller option kit (726821-B21) work without the HPE Smart Storage Battery (727258-B21) installed?

If "Yes, it can" is the answer...can I add the HPE Smart Storage Battery (727258-B21) at later time (provided that this later addition will require an adequate Server maintenance window)?

Thanks!

[Torsten.]

The controller needs the battery in order to use the write cache safely.

The Gen9 server series need only a single battery for multiple controllers, older controllers need an own battery each.

[parnassus]

Hello Torsten, thanks for answering.

I still have a doubt: if the HPE Smart Array P440/4G doesn't find the HPE Smart Storage Battery properly fitted...will it work "normally" (with the Write Cache disabled and lowered performance) or will it not work at all?

That's the point for me, I mean: I can survive for a week or so with the Write Cache disabled and a Smart Array Controller working (consider that, in meantime, I have a very good UPS protecting the Server)...instead...I really can't survive with a non functioning Smart Array Controller due to the - temporarily - lack of that battery option.

I need to understand that (I know the benefits of having the HPE Smart Storage Battery fitted).

Thanks!

[Jimmy Vance]

---

@parnassus wrote:

Hello all,

In reading the latest HPE Smart Array P440 Controller QuickSpecs (August 2016, here) I noticed that the HPE Smart Array P440/4G Controller option kit (726821-B21) - with respect to the other possible HPE Smart Array P440/2G Controller option kit (820834-B21) - doesn't include the HPE Smart Storage Battery (727258-B21) which acts as the backup power source necessary to protect the Controller data on its Flash-backed Write Cache).

A note in that QuickSpecs says:

"HPE Smart Array P440/4GB FBWC controller option kit does not include the HPE Smart Storage Battery the backup power source necessary to protect the data on the Flash-backed Write Cache. HPE Smart Storage Battery is an item that has to be purchased separately if this is the first P-series Smart Array controller on your Gen9 server."

My question is about sentencing: that "...is an item that has to be purchased if..." means that the presence of the HPE Smart Storage Battery is mandatory for the (first/single) HPE Smart Array P440/4G Controller option kit (726821-B21) to work or just that it's only highly recommended but not mandatory?

In other terms: Can the HPE Smart Array P440/4G Controller option kit (726821-B21) work without the HPE Smart Storage Battery (727258-B21) installed?

If "Yes, it can" is the answer...can I add the HPE Smart Storage Battery (727258-B21) at later time (provided that this later addition will require an adequate Server maintenance window)?

Thanks!

---

Any Smart Array controller with a cache module requires the smart storage battery.  For Gen9 one battery can work with several controllers. Previous generations of servers required a seperate battery for each controller. Without the battery performance will suffer, and if I recall correctly you can only create RAID levels 0 and 1 without having a working battery in the system.

[Torsten.]

The battery is an option, hence the controller works without.

In case of a power failure the battery delivers power to the controller, so the controller can write the cache contents to a special flash memory to save the data. Without battery no write cache, because data may be lost in case of power failure.

[parnassus]

OK, that sounds a little more reasonable to me. Thanks Torsten!

Last question...since you cited the Smart Array RAID 0/1 creation restriction in case the HPE Smart Cache Battery is not fitted...can you confirm that?

Is there a document that will explain what are the operating restrictions (temporary or definitive) for a Smart Array Controller initially operated without its Smart Cache Battery?

The fact that I will not be able to create a RAID 6 Volume if the battery is not equipped could be a real (deployment) stopper to me...so I will be forced to wait for the battery to arrive before setting up the whole Server.

[Torsten.]

From the quickspec you already know:

4 GiBytes Flash Backed Write Cache (FBWC) or 4 GiBytes Flash Backed Write Cache kit with Battery (FBWC) provides read ahead caching and write back caching with indefinite write cache data retention in the case of unexpected power outage

...

Standard on the P440 are RAID 6, RAID 60, RAID 1 ADM, Capacity Expansion, mirror split, recombine, and rollback in Online Mode, Drive Erase, Performance Optimization-Degraded Reads and Read Coalescing, Move/Delete any individual LUNS

[Jimmy Vance]

Buy a battery, it is not "optional"

---

@parnassus wrote:

"HPE Smart Storage Battery is an item that has to be purchased separately if this is the first P-series Smart Array controller on your Gen9 server."

My question is about sentencing: that "...is an item that has to be purchased if..." means that the presence of the HPE Smart Storage Battery is mandatory for the (first/single) HPE Smart Array P440/4G Controller option kit (726821-B21) to work or just that it's only highly recommended but not mandatory?

---

Your original question didn't include the entire sentence.  "is an item that has to be purchased separately if this is the first P-series Smart Array controller on your Gen9 server."

The battery isn't an option, it is a required part for the proper operation of the smart array controller. Since Gen9 can share the battery amongst several controllers you only need to purchase one if a "P" series controller was not included in the original SKU. Will a controller function without a battery, yes it will, but not fully functional as it isn't designed to work without one.

[parnassus]

Sorry Torsten...I'm an old school guy...I don't want to be too pedantic but a clarification is necessary: yes, I already know what QuickSpecs document states and I already know that performance degradation should be expected when no HPE Smart Storage Battery is present...that's not the point...what I don't know now is if there could be Smart Array Controller functionality restrictions/limitations when no FWBC is present (you wrote that you probably recall something about that possibility).

The point is...since you said that Smart Array Controller may be limited in creating only RAID 0/1 Volumes when not equipped with HPE Smart Storage Battery instead of offering its whole RAID levels capabilities (RAID 0, 1, 10, 5, 50, 6, 60 and 10 ADM) when the HPE Smart Storage Battery is present...I asked for a possible clarification but the answer you gave sounded a little bit murky (unclear) to me.

Sorry for that.

For sure, re-reading the QuickSpecs, a statement shows up:

"It features eight internal physical links and delivers increased server uptime by providing advanced storage functionality, including online RAID level migration between any RAID levels with flash-backed write cache (FBWC), global online spare, and pre-failure warnings"

so, at this point, for sure the Online RAID level migration functionality requires the FBWC presence but doesn't say nothing about the absence of the HPE Smart Storage Battery.

[parnassus]

Thanks Jimmy

No no...I reported the whole sentence (see above)...what I asked - referring to sentencing about a part of that whole sentence - is about the fact that HPE didn't wrote explicitly "You must purchase and install the HPE Smart Storage Battery..." (independently that that Controller is the first one or not) but wrote instead "HPE Smart Storage Battery is an item that has to be purchased separately..."...giving the user two possible alternatives...using the HPE Smart Storage Battery (thing I want to do) and not using the HPE Smart Storage Battery (thing I probably will be forced to do for some time during deployment)...these are two very different things IMHO.

Since I'm not English mother tongue...I ask: is the "it has to..." equal to "it must..."? great doubt.

HPE Documentation left the user arguing if the HPE Smart Storage Battery option is (really) essential or not and if the HPE Smart Array P440/4G Controller functionalities (not its performances!) shall be impaired heavily or not for the absence of that battery.

It's not a matter of not purchasing a few bucks option...it's a matter of be clear and simple.

That QS doesn't say practically nothing about that.

Very vague IMHO.

P.S.

OT start

I found interesting that the P440/2G has the HPE Smart Storage Battery option included while the P440/4G has not!

That's the Intricacy Office sign...isn't it?

OT end

[Torsten.]

What server model do you have?

[parnassus]

Hi!

Short answer: HPE Product Number L9N12A (the sticker says: HP DL180 Gen9 E5-2609v3 SP8027TV EU Svr) came pre-equipped with HPE Smart Array P440/4G from factory, 8GB DDR4 (I then purchased separately 4x16 GB DDR4 banks and HPE disks) and 8 LFF Disks Cage.

Long answer: this thread where you contributed yet.

Side note: the Server is finally in my own hands today but I hadn't time - while I'm writing this post - to verify IF the pre-equipped HPE Smart Array P440/4G came with the HPE Smart Storage Battery or not (this explains why I started this thread after I read the relevant QS document with that note)...wait...the distributor wrote in the selling document "...with battery"...so I'm PROBABLY safe. Eureka!

The point is I don't trust what the Distributor wrote, I must see...because they could have translated the FWBC with "with Battery" and they didn't wrote "with HPE Smart Storage Battery" explicitly. I'll check tomorrow morning.

At this point all the HPE Smart Storage Battery related doubts I raised above will continue to be valid...probably they gain more significance if the HPE Smart Controller P440/4G is purchased as a separate option (not pre-equipped)...

[parnassus]

Update: the DL180 Gen9 factory equipped with the HPE Smart Array P440/4G with 4G FWBC was also factory equipped with the HPE Smart Storage Battery kit, I've taken a shot:

 So far, so good.

[Torsten.]

Looks like your problem is solved now ...

[parnassus]

Well, not.

I was only lucky (shame on me!) in purchasing a pre-factored HPE ProLiant DL180 Gen9 Server model pre-equipped with the HPE Smart Array P440/4G and the proper HPE Smart Storage Battery...but, even if the doubt of receiving a Server equipeed without that HPE Smart Storage Battery passed away, that was the reason I initially raised all those (theoretical) questions.

I think that would be interesting to definitely understand if those questions are still valid or not: think if the HPE Smart Storage Battery will suddenly fail (or if it, as written, was not available at Server purchase time)...which impairments will hit the Server storage subsystem and which restictions will hit the Server deployment (no RAID6?), apart storage subsystem performance's degradation?

Probably too theoretical...

[Torsten. · Accepted solution]

Older controllers were sold with or without cache, so such controller without cache cannot do RAID5 or RAID6 at all. Your controller has always cache integrated, so it can do these RAID levels.

Yesterday I had a DL360 Gen9 with a P440ar installed and a completely failed storage battery. The RAID (it was RAID1 and RAID5) was accessible, but the performance was low. So the server will work without or with a failed battery, but slow.

You can test this too, set up your server, power off, disconnect the battery and power up - just to prof it.

[parnassus]

Thanks Torsten, that's exactly what I want to test...so the presence/absence of the HPE Smart Storage Battery doesn't impair HPE Smart Array Controller's features (e.g. the ability to deploy various RAID levels according to Controller capabilities), it has a direct impact on the Controller's performance.

The 2G/4G FWBC module is another matter...I know.

[Jimmy Vance]

I just tested and the newer controllers like the P440 don't appear to have the limitations of the older controllers requireing a battery to create or modify advanced RAID levels. The older controllers would still function at their current level with a bad battery, you just couldn't modify or add an array.

[parnassus]

That's a good info! Thanks for testing!

Now I'm facing another question HPE Smart Array P440/4G related to "Offline - without SPP - Firmware update" but I'm going to open another Thread about that here (Solved, thanks again to @Jimmy Vance and @Torsten.).

[PCW_INTAS]

Hi Jimmy

I don't know if we can reopen this thread but I have the same problem with the P440 controller batteries but in my case "just buy a battery" is not an option. I have approached the local HP resellers with a request for supply of replacement batteries for our G9 servers (67 of them) and they said that they could provide one. One battery! Stocks in Australia are otherwise out and there are supposedly no after-market suppliers either. Is this as a result of a trend perhaps?

Irrespective of that, the thought of having to go around the country to replace all the cache batteries every couple of years is not something I want to have to do. Some of our sites are remote with no on-site tech support.

Our servers are used for air traffic control. So far we have had nearly 20% of them fail with bad batteries and warranty is yet to run out (although imminent). In at least one case, the failure brought down the server with temporary loss of access to the disk sub-system requiring technician attendance to initiate a reboot. As you may imagine with ATC we cannot afford unscheduled outages so the fact that we could recover operations is of no comfort. We instal our systems with duplicated high reliability UPS systems and generator backup. Power outages are not something we can reasonably allow nor are unscheduled server crashes.

The fact that these systems will apparently run quite happily without batteries suggests to me that we should be able to simply remove them. Given our high availability power systems, I suggest that that will improve reliability and the loss of performance will in our case go unnoticed. I have suggested this to HP support personnel and the local reseller and met resistance to the suggestion. Alternatively could we not go the super cap route? My enquiries along those lines have also been fruitless so far.

We have DL360s with Raid 1 and DL380s with Raid 1 plus Raid 5.

Regards

Peter

[HPSDMike]

The systems will run fine without a battery but write cache will be disabled. Depending on how you are using the system, the performance impact could range from nothing to devastating. If you're just using these as a local boot partition for, say ESXi, and using a SAN for the VMs then you'll likely see no issue.

Unfortunately batteries do fail over time (think of anything you have with a rechargable battery like a cell phone). Replacement of the batteries are covered under warranty and you should also be able to purchase extras if you want spares outside of the normal break/fix process. 

Due to normal lifecycle proceses, the part number for this battery has recently changed so this may be why you were having issues finding supply. Make sure you are checking with the new part numbers.

HP 96W Smart Storage Battery with 145mm Cable
Gen9 & Gen10: P01366-B21

HPE 96W Smart Storage Battery with 260mm Cable
Gen9 & Gen10: P01367-B21

HPE 12W Smart Storage Battery
Gen9 & Gen10: P01363-B21

HPE 12W Smart Storage Battery with Plug Connector, 230mm cable
Gen9 & Gen10: P01364-B21

HPE 12W Smart Storage Battery with plug, 609mm cable
Gen9 & Gen10: P01365-B21

[PCW_INTAS]

Thanks, that helps.

As for the performance impact, I would expect that we fall into the category of not noticing any difference based on what we have seen when the batteries have failed. For those servers that have have continued operating without crashing, users haven't noticed and maintenance techs have only become aware as a result of automated fault reporting.

My desire is to permanently remove the batteries on the DL360s which are all running only Raid1. We can more easily manage a battery replacement program for the DL380s as those machines are all running as master/slave duplicated pairs. The DL360s are single units running as dedicated display managers so to progressively shut them all down for scheduled maintenance is more disruptive to ATC operations.

If the battery is removed, can the self test be configured to accept it without flagging a fault or flashing the front panel LED? I've had a quick look in the BIOS but can't see anything obvious.

[Torsten.]

There were several issues related to the battery in the past that have been resolved by ILO and BIOS updates like this:

https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-a00017918en_us

make sure ILO and BIOS and smart array versions are current.

>> can the self test be configured to accept it without flagging a fault

IMHO you need at least set the write cache ratio to 0% (disable write caching).

Otherwise the controller "remembers" this setting, even if write cache is temp. disabled because of the missing battery.

[Threonine]

It's worth noting that without write caching you cannot perform array expansions, logical drive extensions, strip size migrations, and RAID migrations. See the "Write caches" section in the paper "HP Smart Array Controller Technology".