Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow (1014 Views)
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Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 1 of 18 (1,016 Views)
Accepted Solution

Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Hi,

 

Having a problem on our new system with restore times from a Ultrium 3280 SAS tape Drive to a D2700 disk enclosure.

 

The backup of 220Gb of oracle data/index tables took about 25 minutes - however the restore of the same data set took about 15 hours! Help!

 

The server is a RX2800 Integrity running VMS 8.4.

 

I have seen in other posts various comments about turning off High water marking - which I tried - no noticeable differences in restore times. I have also tried putting the DIOLM to 8 on the SYSTEM account I am using for backups. As well as setting the PQL_MDIOLM to 8 before backups and then back to 100 after. Again no difference in timings.

 

Any ideas please.

 

 

Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 2 of 18 (1,014 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

meant to say here are the commands I used for the Backup and then the restore:-

 

$ init/over=(own,exp,acc) $2$MGA0: backup
$ mount/block=32768/for $2$MGA0: backup

 

$ back/media_format=compact/ignore=label/rew/nocrc/record/block=32768 -
  dkb100:[oracle_redo]*.* -
  $2$MGA0:data1.bck /save -
  /list = sys$backup:data1.lis /log
$!
$ back/media_format=compact/ignore=label/nocrc/record/block=32768 -
  dkb200:[oracle_data]*.* -
  $2$MGA0:data2.bck /save -
  /list = sys$backup:data2.lis /log
$!
$ back/media_format=compact/ignore=label/nocrc/record/block=32768 -
  dkb300:[oracle_idx]*.* -
  $2$MGA0:data3.bck /save -
  /list = sys$backup:data3.lis /log

 

 

 

And then on the restore side I went with

 

$MOUNT/FOR $2$MGA0:BACKUP
$BACKUP $2$mga0:DATA1.BCK DKB100:[ORACLE_REDO]*.*
$BACKUP $2$mga0:DATA2.BCK DKB200:[ORACLE_DATA]*.*
$BACKUP $2$mga0:DATA3.BCK DKB300:[ORACLE_IDX]*.*

 

 

 

 


 

Honored Contributor
Hoff
Posts: 4,948
Registered: ‎01-29-2006
Message 3 of 18 (1,005 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Is there a remote link involved here, as was the case in this thread?  If so, how fast is this link?

 

Are your BACKUP username process quotas per specification?

 

What is your rx2800 i2 storage hardware configuration; the details of your disk and tape I/O devices and paths? 

 

What else have you tried?  Does a disk-to-disk restore show the same timing and the same behavior?  Does a local tape-to-disk restore show the same timing?

 

And one general process question,  why are you using tape in what appears to be a time-critical DT configuration?  Can you get the Oracle giblets to put a backup or at least a journal directly on the remote box?

 

If this is the same configuration that was discussed before, there is no particular fix for a network connection that isn't sufficient for your time requirements, though it's possible that migrating to data compression MIGHT help reduce the contention on that data link SOMEWHAT.  That's data compression, and not media compaction.   Media compaction occurs entirely within the device, and that means that the uncompressed data will travels over that site-to-site network link, where data compression and data decompression occurs within BACKUP and that might reduce the volume of bits over the link at the cost of higher CPU overhead.

Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 4 of 18 (994 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Hi Hoff,

 

Thanks

theres no "link" involved here

this is the new system totally standalone

Tape Drive connected to the integrity server adapter P411

D2700 connected via another P411 adapter

 

backup is super fast 220Gb at 20mins

restore is painfully slow at 15 hours!

 

will get back to you tomorrow re your other questions here

thanks

 

Trusted Contributor
abrsvc
Posts: 365
Registered: ‎06-08-2010
Message 5 of 18 (990 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

As Hoff suggested, I would recommend trying a pass disk-to-disk. Eliminate the tapedrive completely. See if the problem is the restore behavior alone.

Dan
Honored Contributor
Volker Halle
Posts: 5,205
Registered: ‎04-26-2004
Message 6 of 18 (983 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Robert70,

 

consider doing a BACKUP/LIS=filename $2$MGA0:*.*/SAVE/REWIND to time the read operations from tape. If this operation seems still 'very slow', consider even using /LIST=NLA0: If that is also slow, it must be the tape drive or the IO path to the tape.

 

Does ANALYZE/SYSTEM SDA> FC PERFORMANCE also do FC tape performance ? It's worth a try.

 

Volker.

Frequent Advisor
Eberhard Heuser
Posts: 43
Registered: ‎03-19-2010
Message 7 of 18 (967 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Did you try /block=32256 instead of 32768?

 

This is the number I alway see in the recommendations.

 

Eberhard

Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 8 of 18 (960 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

disk to disk backup/restore

 

backup of 3 files 35mb each took 6 seconds

restore of same data set took 93 seconds

 

so this would highlight a problem with the restore op and nothing to do with the tape and its config/connection.

 

 

Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 9 of 18 (956 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Here’s the problem:
one of the adapter has NO write cache!

Adapter: _PKC0:
P411 (c) HP PACCTID11350SH7 Software 5.06
Port Address: 50014380-16c2f090
Supported Redundancy Mode: Not Available.
Cache:
144 megabyte read cache 0 megabyte write cache
Cache is GOOD, and Cache is enabled.
No unflushed data in cache.
Battery:
Battery is not reported as present.

Honored Contributor
Hoff
Posts: 4,948
Registered: ‎01-29-2006
Message 10 of 18 (952 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

[ Edited ]

Given the lack of details, I'd suggest starting with the process quotas (as those can hammer performance), then check for and apply patches, then check for a fragmented disk or a near-capacity disk, then call HP support for a look at what you're doing, and to if they can replicate it and resolve it.

 

This could well be a command error, a problem with the hardware configuration, a problem with the hardware, a fragmented disk, or a bug in BACKUP or in a lower-level component.

 

Edit: And I see you have a problem with the hardware configuration.

Trusted Contributor
abrsvc
Posts: 365
Registered: ‎06-08-2010
Message 11 of 18 (947 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

To verify that the adapter is the culprit here, I would confirm by using the same test on a system with an adapter that has the cache enabled.  If the adapter is the problem, then the new test should show a significant performance difference.  Also, as stated by Hoff, process quotas etc can significantly affect Backup performance.  For the confirmation testing, be sure that the accounts, quotas etc be consistant.

 

Dan

Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 12 of 18 (938 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

ran the test on another disk connected via another adapter - restore as quick as backup - adapter write cache looks like the problem
Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 13 of 18 (933 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

how can the write cache on the P411 be set? is this software enabled?
Honored Contributor
Volker Halle
Posts: 5,205
Registered: ‎04-26-2004
Message 14 of 18 (929 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

robert70,

 

Battery:
Battery is not reported as present.

 

That could be a reason. Storage controllers typically don't allow you to use WRITE caches, if there is no battery available !

 

Volker.

Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 15 of 18 (927 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

understood - so either i have a hardware problem in that controller or more likely the controller dosent have the battery installed and hence no write cache enabled
Honored Contributor
Hoff
Posts: 4,948
Registered: ‎01-29-2006
Message 16 of 18 (918 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Or the battery has failed; cache batteries have been known to do that.

 

Call hardware services.  

 

Your organization pays good money for that access into HP, use it.

Trusted Contributor
abrsvc
Posts: 365
Registered: ‎06-08-2010
Message 17 of 18 (917 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

Per the documentation the HP 650 battery is required to enable the write cache feature. With the battery "not present", the write cache is thus disabled.

Check the battery cable connection. I have seen these get dislodged. Even a re-seat might help.

These batteries run about $60 or so.

Dan
Super Advisor
robert70
Posts: 337
Registered: ‎10-20-2004
Message 18 of 18 (908 Views)

Re: Ultrium 3280 SAS Tape Drive on RX2800 - Restores times very slow

thank you very much for your help
i have now riased this with HP who are organising a battery and 512mb cache kit
cheers to all
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