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XP12000 formatting takes long time

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jrodriguez_1
Occasional Visitor

XP12000 formatting takes long time

We have a XP12000 array. We created a 500 GB Open-V CVS LDEV in order to present it to a Windows system. We created and formatted the space from the StorageWorks XP Remote Web Console. The very odd thing is that formatting this space took about 70 hours. It seems that from the Web console there is no way to change velocity or priority. Is our assumption true? Any help/suggestions to reduce formatting time will be greatly appreciated.
11 REPLIES
Amar_Joshi
Honored Contributor

Re: XP12000 formatting takes long time

It depends upon how is the load on XP and what kind of HW configuration you have. RAID5 disk formatting will be slower and on bigger capacity disks it will be even slower. If the DKA port used for the undergoing disks is shared with high IO activity disks in the same path then it will impact too.

My experience says that the formatting from the CVXP is always slower than the formatting done from the SVP (during the HW installation). If the disks are totally free and this is the first LUN you are formatting on the Arraygroup then it would be better if you can De-install the AG and re-install (with the help of HP engineer) and format the LUNs at the same time.

I haven't seen anything taking more than 24 hrs but 70Hrs is too much to handle. You may ask HP to review your configuration if you have any hot spot in your XP12000.

Nigel Poulton
Respected Contributor
Solution

Re: XP12000 formatting takes long time

I can believe 70 hours - especially if its on large disks and if there is a lot of host I/O. Ive seen 18GB taking 2.5 hours.... and -

500/18 = 27.7
27.7x2.5=69
Close enough.

Might be worth asking your CE about mode 269 (I think thats the mode) which brings RWC format times into line with SVP times.

Hope this helps
Talk about the XP and EVA @ http://blog.nigelpoulton.com
Amar_Joshi
Honored Contributor

Re: XP12000 formatting takes long time

Nigel,

You are talking about 18GB which was last supported on XP152. Knowing the differences between the XP generations and fast formatting of Hitachi disks over Seagate disks (due to onboard CHIP integration on Hitachi disks) is likely to fade you out from debate. All I suspect is the load on XP or something to do with microcode. Please check with HP about it and make sure you are not running legacy microcode.
Nigel Poulton
Respected Contributor

Re: XP12000 formatting takes long time

Thanks Amardeep,

I was not clear, this is on a XP12K/USP with very recent MC. I was cutting 18GB LDEVs. Some were RAID10 on 146GB 15K spindles and some were RAID5(3+1) on 300GB 10K spindles.

It was taking 2.5 hours to cut an 18GB LDEV!!

Nigel

Talk about the XP and EVA @ http://blog.nigelpoulton.com
Nigel Poulton
Respected Contributor

Re: XP12000 formatting takes long time

Also just checked and the drives are a mix of Seagate and Hitachi -

146 DKSxxx Seagate
300 DKRxxx Hitachi
Talk about the XP and EVA @ http://blog.nigelpoulton.com
jrodriguez_1
Occasional Visitor

Re: XP12000 formatting takes long time

Sirs, your comments help me to clarify that weâ ve not made a mistake, but formatting time is an issue for XP12000.
Just FYI, our firmware version is 50-07-51 (weâ ll install the new version next month), but I do not expect a great formatting time improvement by this upgrade.
Also as you stated in you replays some configuration issues may help for a faster formatting (or seems so). For instance, our first cuts were 200GB, 200GB and 100GB (total=500GB) all on the same Array Group; after you comments, we define the same cuts (200GB, 200GB and 100GB), but one of the 200GB cuts in a different Array Group; the formatting time then, took about 50 hours, and not 70. We are not sure if is a direct consequence of the change or a variation of the I/O activity.
Again, based on you experience, and assuming that weâ ll not reduce formatting time to a couple of hours, do you have a strategy to reduce the time between a userâ s storage space requirement and the delivery time of this space to the user. For instance, pre-creating pools of cuts of fixed sizes, and then when a user asks for space, build a LUSE with these cuts, avoiding by this way, the formatting time.
Your suggestions and creative ideas will be appreciated.
Nigel Poulton
Respected Contributor

Re: XP12000 formatting takes long time

Your thoughts on pre-cutting LDEVs of a fixed size and then using LUSE or a host based volume manager to create larger volumes is a good one and commonly in use by many XP/USP customers.

Having a small number of common LUN sizes also helps in a tiered storage environment and when performing ad hoc migrations (as these array based technologies require source and target volumes to be exactly the same block size).

It is a very bad idea to have lots of different LDEV siezes on an XP for tiering and other migrations.

Also, if you are formatting all of the space on a Parity Group then have your engineer come on site to pull and re-install the Parity Group as he is able to format the space much quicker from the SVP.

Also ask you engineer about the mode setting which I mentioned in a previous post as this may speed up format times.

Hope this helps
Talk about the XP and EVA @ http://blog.nigelpoulton.com
jrodriguez_1
Occasional Visitor

Re: XP12000 formatting takes long time

This forum comments and suggestions have been very valuable. We'll prepare an startegy to make cuts in the XP12000 in order to reduce space requirements delivery time.
Despite of this, we'll open a ITRC case to get,may be, a more in detail explanation of this behavior, and ask for a correction to reduce formating time,if it is not an engineering limitation issue.

By this message, I am closing this thread. Thank you.
Amar_Joshi
Honored Contributor

Re: XP12000 formatting takes long time

It's just an addition to Nigel's comments about cutting the predefined LUNs and then later using LUSE to form bigger LUNs. I will suggest NOT to do this as a best practice. You may save the formatting time by this but LUSE are slower and looses lot's of performance gained by OPEN-V volumes. So if you are being only concern with formatting time, you can do it but for host performance (in long run) LUSE should be avoided as much as possible.

In my previous post what I meant by cutting the LUNs during the Array Group installation is that to determine the need in advance and cut the desired LUNs while installing AGs. Not meaning that you cut several small LUNs (say 15GB) and then LUSE them to make bigger LUN sizes.

Whatever it is, with current trend of slow formatting on CVXP this gives us indication to plan very well in advance.
jrodriguez_1
Occasional Visitor

Re: XP12000 formatting takes long time

We'll take in account the LUSE performance issue. In the near future, we'll be upgrading our XP12000 boxes with new AGs, then as I stated in my previous post, we'll plan carefully our needs before cutting and formatting.
Thank you again.
jrodriguez_1
Occasional Visitor

Re: XP12000 formatting takes long time

I am closing this thread, because based on the valuable data, comments and suggestions made during this forum life, we could detect that our problem is a funtionality limitation, and we get some tips that can help us in the future.