jfslog not mirrored ..any impact ? 1

[samirm]

Hi,

I have two VGs and for one of them (wms_vg2) the jfslog LV is not mirrored. will that create any problem if the disk fails? We didn't do mirror VG. It was done always "syncvg -l <lv_name>" for all associated LVs. And this time how we can move forward ? Just simply doing "syncvg -l loglv02" or some other thing? Will that create any performance issue? As this is the main prod. server of the business.

wms_vg1:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
wmsora5_lv jfs 1085 2170 2 open/syncd /WMS/ora5
archive1_lv jfs 1626 3252 4 open/syncd /archive
backup_lv jfs 1084 2168 2 open/syncd /backupold
wmsora2a_lv jfs 1085 2170 2 open/syncd /WMS/ora2
wmsora1_lv jfs 1085 2170 2 open/syncd /WMS/ora1
wmsora3_lv jfs 1085 2170 2 open/syncd /WMS/ora3
wmsora4_lv jfs 1085 2170 2 open/syncd /WMS/ora4
loglv00 jfslog 1 2 2 open/syncd N/A


wms_vg2:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
wmsora6_lv jfs 540 1080 2 open/syncd /WMS/ora6
wmsora7_lv jfs 540 1080 2 open/syncd /WMS/ora7
loglv02 jfslog 1 1 1 open/syncd N/A
backupnew_lv jfs 1050 2100 4 open/syncd /backup


Sam

 

[bi]

Figure out which disk the log is on (lslv -m loglv02) and use smitty mklvcopy to add a copy on another disk in the volume group. Be sure to specify you want the data to be synced.

If you don't put a copy on another disk and the disk it is on fails, logical volume manager is going to be very confused.

 

[RMGBELGIUM]

the creation and sync of a jfslog,it's just 1 PP in size, that won't impact the performance.If you loose you jfslog, your VG will crash.Then you will have to create a new log.My advice is : mirror the jfslog , preferrably onto another disk in the VG

rgds,

R.

 

[p5wizard]

> If you don't put a copy on another disk and the disk it is on fails,
> logical volume manager is going to be very confused

Not only will LVM be confused, you will lose access to the data in the filesystems in that VG.

If you want to mirror stuff in a VG, mirror all the LVs or at least the jfslog (jfslog2) and the LVs you want to keep accessing after a disk crash.


HTH,

p5wizard

 

[samirm]

Thanks to all for the support.
I made the lvcopy and did sysncvg ..
my jfslog looks fine now ..

Sam