Hi Art:
What kind of data is contained on the vol? Is it one huge file (DB) or a bajillion little ones? Have you thought about trying the reallocate when things are quiet? (no users or db offline)
-john
-----Original Message----- From: Art Hebert [mailto:art@arzoon.com] Sent: Thursday, February 13, 2003 5:42 PM To: 'jwitham@takedapharm.com'; Ambrose_Earle@shamrockfoods.com; toasters@mathworks.com Subject: wafl scan reallocate not improving layout?
I have a volume that shows a layout of 5 when doing a wafl scan measure layout. I have tried reallocating it but it never gets below 5. Using statit the data seems to be laid out evenly, 4.2 is the parity disk.
disk ut% xfers ureads--chain-usecs writes--chain-usecs cpreads-chain-usecs /vol/vol0 group 0: 4.2 3 4.22 0.43 1.00 23079 2.72 3.80 2986847599971 1.06 2.46 2182 4.4 39 79.56 77.18 1.91 2574 1.33 4.46 3793820692012 1.04 2.40 2365 4.1 37 76.72 74.81 1.91 2553 0.93 5.28 3193299281907 0.97 3.02 1613 4.6 41 83.67 81.56 1.88 2624 1.35 4.72 2462422822812 0.76 2.51 2198 4.0 40 83.62 81.77 1.87 2562 1.03 5.83 2711737467108 0.82 2.61 1959 4.3 40 83.70 81.83 1.86 2594 1.06 5.74 2738534194560 0.81 2.47 2055 4.5 40 84.04 82.17 1.86 2579 1.07 5.72 2611584689054 0.80 2.50 2099
Should I cease activity to the filer and run the wafl reallocate then?
Thoughts and thanks
art
-----Original Message----- From: jwitham@takedapharm.com [mailto:jwitham@takedapharm.com] Sent: Tuesday, January 28, 2003 10:39 AM To: Ambrose_Earle@shamrockfoods.com; toasters@mathworks.com Subject: RE: wafl scan
We use 'wafl scan reallocate' weekly to reorder our Exchange 5.5 databases. They keep growing, and are over 100GB apiece. The wafl scan reallocate helps our use of SnapManager verifications greatly. We have been known to run it in the middle of the day, but with a big performance hit (as you have seen). Haven't tried it in conjunction with SnapMirror.
Just for grins, we also use 'wafl scan measure_layout' before and after the reallocate to ensure that we've accomplished something. We affectionately refer to the process as 'reshuffling the wafl house'.
HTH,
-john
-----Original Message----- From: Ambrose_Earle@shamrockfoods.com [mailto:Ambrose_Earle@shamrockfoods.com mailto:Ambrose_Earle@shamrockfoods.com ] Sent: Thursday, January 23, 2003 7:28 PM To: toasters@mathworks.com Subject: wafl scan
Does anyone have any (good) experience with the wafl scan commands?
I am testing Snapmirror and used it to mirror 7x34's to 10x34's. Of course, the data was only written to the first seven drives, so I used 'wafl scan reallocate <volume>' and it seemed to improve the layout quite dramatically. Is this a good use of the command? Other than affecting performance, I'm assuming everything is accessible during the run of this command?
Thanks in advance,
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