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Recommanded partition

former_member201054
Contributor
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I have to design and determine the partiton size for Windows and SQL 2005 .Please suggest the needed paritions with mirroring option (or) general recommended one.

I would appreciate your help.

Accepted Solutions (1)

Accepted Solutions (1)

Former Member
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Hi,

Check installation document for sap on windows SQL server.

for sizing check service.sap.com/sizing

regards,

kaushal

former_member201054
Contributor
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Normally I would set

C- 25 GB for OS

D- 25 GB for paging

E- 100 GB for translog( will vary based on available space)

D- 350 GB for datadase (will vary based on available space )

Should I have to assign space for mirroring also - a separate partition is necessary?

If its so where to mention this mirroring partition at the time of installation?...this mirroring concept is my so long doubt.

More guidance and brief explanation would be grateful and apprciated.

Former Member
0 Kudos

>

> Normally I would set

>

> C- 25 GB for OS

> D- 25 GB for paging

> E- 100 GB for translog( will vary based on available space)

> D- 350 GB for datadase (will vary based on available space )

>

> Should I have to assign space for mirroring also - a separate partition is necessary?

>

> If its so where to mention this mirroring partition at the time of installation?...this mirroring concept is my so long doubt.

>

> More guidance and brief explanation would be grateful and apprciated.

You should size the paging partition by the size of the memory installed.

It is recommended you have paging = 2 x memory.

So 25 GB would be fine for 8 GB of installed memory, but if you have 16 or 32, you'll need to size it accordingly...

former_member201054
Contributor
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Sure..thanks.

Please shed some light on mirroing the database and translog partition and where to mention it at the time of installtion. From my experience I have not noticed any specific path to mention database mirroing partition during installtion.

Should we have to mirror the database and trans log manually or since we use RAID 5 we need not to worry about mirroing in SQL 2005.

I would appreciate your help and suggestion.

Former Member
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Hi,

As you already have Raid 5 you do not need to mirror the database, in fact I didn't know it was possible in SQL server but I´m not very familiar with SQL.

Tell me something, you are using RAID 5 for the database and raid 1 for OS and application files and programs, Am I right?, if so, I will suggest you to use a different partition (not raid5) for the trans log than the one you are using for the database so they will write in different physical disks. It is better for the database performance and also for security reasons.

former_member201054
Contributor
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I keep database on RAID 5 and translog on RAID 1 in diffrent disk location. Is it possible to make another copy (mirroring) of both at a separate disk automatically; it should get updated along with original DB and translog ,so we can use it for restore and recovery even if we lose the original.

Should we have to do anything manually in SQL 2005 to attain this.I would appreciate your help and suggestion.

Former Member
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You already have redundancy on disks, Usually with High Availability systems, disks are on a SAM (or similar) and the servers connect to it so when one server goes bad, the Cluster takes on, and the service (SAP or whatever you need) keeps going after a few minutes (Active- passive) or in no time (Active- Active).

As you can see, disks on arrays are not that easy to get bad and if so, you can replace the bad one and keep going, in the other hand, if the server (hardware) goes bad then you need another one to replace it but in your case you would need to take the disks out from one server to the other.

If any system have to write 4 times then performance will suffer a lot, for RAID 1 disks the system has to write all info twice that´s why it is not used for databases, now imagine if the system have to write it 4 times. In RAID 5, info is written with parity so if something goes wrong with one disk, the data can be reconstructed but calculating parity and segments to write also consumes time on the CPU so if you multiply by 2 then CPU will suffer too.

If you want, you could have a second server so you could do backups and save them to those disks so it is faster to backup or restore, in the event of the PROD server to go bad then you could use the same server (if they are the same) to move your disks and get everything up and running in a minimal downtime.

New servers (most models used for SAP) have memory redundancy, disk controller redundancy, power redundancy, etc so it is very difficult to have a major failure on those systems.

former_member201054
Contributor
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deserved for full points..wonderful.

Answers (0)