Classification: Confidential Yup!
-----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Peter Sent: Monday, September 9, 2024 11:22 PM To: [email protected] Subject: Re: Storage Solution selection Criteria [CAUTION: This Email is from outside the Organization. Unless you trust the sender, Don’t click links or open attachments as it may be a Phishing email, which can steal your Information and compromise your Computer.] So IOPS is not the right way of measuring for mainframe data So there is a big difference between IOPS and Response time On Sun, 8 Sept 2024, 16:37 Nigel Morton, < [email protected]> wrote: > IOPS means I/Os per second so it's a measure of the throughput of the > devices. In practice, with z/OS you won't generate anywhere near the > maximum IOPs for a modern all-flash storage device. IMHO response time > is a more useful measure for performance especially as IOPs figures > will probably come from synthetic benchmarks. > > Also consider how you'll migrate from an old storage system to a new one. > Copy services functions such as multi-target metro mirror are > excellent but will almost certainly require that the source and target > vendor are the same. You might also need to consider what type of > FICON adapters can coexist with your FICON switches and channels. > > On Sun, 8 Sept 2024 at 05:04, Peter < > [email protected]> wrote: > > > Hello > > > > > > I have seen a term called IOPS in the technical sheet > > > > > > > > From the storage perspective what does IOPS do? How does that > > influence > on > > storage solution selection? > > > > On Thu, 5 Sept 2024, 16:03 Radoslaw Skorupka, < > > [email protected]> wrote: > > > > > Cache - the more the better. Obvious. However there are different > > > ways of use of DRAM as a cache. > > > Some vendors have cache mirrored. Others don't mirror READ cache. > > > Usually the same memory is used for other purposes, not only for > caching > > > READs and WRITEs. So, "1TB of cache" is not simply comparable > > > between vendors. > > > > > > Disk module. SSD or magnetic? Usually SSD nowadays. But which SSD? > There > > > are many flavours and capacities. > > > Usually smaller modules gives better overall performance. And > > > better flexibility. And there are faster and slower modules. > > > > > > Remote copy. > > > Do you want to perform PiT copy on secondary/slave? > > > Do you want asynchronous copy? > > > Do you want PPRC and FLASHCOPY command compatibility? > > > What QoS features of PiT and Remote Copy do you want? > > > etc. > > > > > > > > > -- > > > Radoslaw Skorupka > > > Lodz, Poland > > > > > > > > > > > > > > > W dniu 04.09.2024 o 20:27, Peter pisze: > > > > Thanks for the inputs > > > > > > > > Currently we are metro mirrored. > > > > > > > > So I believe I also need to look into their quality of support? > > > > > > > > Cache and modules? - what exactly I need to be researching on this ? > > > > > > > > On Wed, 4 Sept 2024, 19:40 Radoslaw Skorupka, < > > > > [email protected]> wrote: > > > > > > > >> W dniu 04.09.2024 o 10:52, Peter pisze: > > > >>> Hello, > > > >>> > > > >>> I Must confess that I am not a Storage expert. In our > > > >>> organization > > we > > > >> are > > > >>> working on procuring a new storage box solution. I have been > > > >>> asked > to > > > >>> study and give an opinion on which solution would be perfect > > > >>> for > our > > > >>> mainframe environment. > > > >>> > > > >>> Could someone give me your advise based on your experience. > > > >>> When > > > >> selecting > > > >>> a new storage solution what are the important points that > > > >>> needs to > be > > > >>> looked into the vendors proposal ? > > > >> Generally speaking a DASD box is not just a bunch of disks. It > > > >> is > DASD > > > >> space + performance + embedded software. > > > >> > > > >> DASD space - obvious > > > >> > > > >> performance - a little bit more complex. There is no single > > > >> number, > > like > > > >> car velocity. Even cache size should be understood, because > > > >> vendors > > have > > > >> different way of use of it. Two approaches: compare "guts" > > > >> (cache, > > disk > > > >> modules, etc.) or compare benchmarks. > > > >> > > > >> embedded software - remote copy, point in time copy, some "obvious" > > > >> things like SuperPAV, etc. Unless you have specific > > > >> requirements all vendors apply. However their offering differ > > > >> and it could be > > important. > > > >> And features like Safeguarded copy. > > > >> > > > >> ...and zHyperlink. All vendors have FICON32 nowadays, and AFAIK > > > >> all > do > > > >> have zHyperlink. > > > >> > > > >> > > > >> HTH > > > >> > > > >> -- > > > >> Radoslaw Skorupka > > > >> Lodz, Poland > > > >> > > > >> > > > > > > ------------------------------------------------------------------ > > > ---- For IBM-MAIN subscribe / signoff / archive access > > > instructions, send email to [email protected] with the > > > message: INFO IBM-MAIN > > > > > > > -------------------------------------------------------------------- > > -- For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO > > IBM-MAIN > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ::DISCLAIMER:: ________________________________ The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only. E-mail transmission is not guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or may contain viruses in transmission. The e mail and its contents (with or without referred errors) shall therefore not attach any liability on the originator or HCL or its affiliates. Views or opinions, if any, presented in this email are solely those of the author and may not necessarily reflect the views or opinions of HCL or its affiliates. Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of this message without the prior written consent of authorized representative of HCL is strictly prohibited. If you have received this email in error please delete it and notify the sender immediately. Before opening any email and/or attachments, please check them for viruses and other defects. ________________________________ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
