[mythtv-users] Migrating existing recordings to new Storage Groups
skd5aner at gmail.com
Sat Dec 30 03:51:56 UTC 2006
On 12/29/06, Bruce Markey <bjm at lvcm.com> wrote:
> Matt wrote:
> > On 12/29/06, John Drescher <drescherjm at gmail.com> wrote:
> >>> One last question. If I name the new partition the same, it won't be
> >>> a problem. However, what if I want to rename the partition? Is there
> >>> a particular place(s) I can change that easily in the database? If
> >>> not, I can stick with the old name (/mythtv/video). However, I was
> >>> thinking something like creating /mythtv/recordings/ then mounting
> >>> each storage group (drive, in my case) to /mythtv/recordings/group1,
> >>> /mythtv/recordings/group2, etc.
> Go for it. Life is short. Out with the old and in with the new.
> When you go into mythtv-setup "6. Storage Directories" then
> "Default" it will show "/mythtv/video" that it imported from
> your old setting. Highlight this item and press "D"elete or
> "M"enu for a popup to remove it. "(Add New Directory)" to
> input "/mythtv/recordings/group1" and "/mythtv/recordings/group2".
> >> Run mythtv-setup. Then click Storage Directories. Then click default.
> >> Then add or change entries as you wish. Right now I have 7 folders as
> >> I have divided one of my 2 330GB drives in 50GB partitions and
> >> formated them as xfs.
> >> John
> > What's the benefit of partitioning the drive in multiple partitions
> > (and therefore multiple storage groups) rather than one single large
> > partition?
> I think he meant sub-directories ("folders") within the one
> big partition for the whole disk(s). But it is a good question
> I have four hosts each with a local disk mounted as "/video".
> My master "nordtv" has another disk that I mounted as "/archive"
> because that's waht I had been using it for =). Now myth can
> write to both disks and read from both with none of the symlinks
> that I used to use.
> mysql> select * from storagegroup;
> | id | groupname | hostname | dirname |
> | 1 | Default | nordtv | /video/mythtv/ |
> | 2 | Default | nordtv | /archive/mythtv/ |
> | 3 | LiveTV | nordtv | /video/live/ |
> | 4 | LiveTV | nordtv | /archive/live/ |
> | 5 | Big Brother | nordtv | /archive/bb7/ |
> | 6 | Default | sleepy | /video/mythtv/ |
> | 7 | LiveTV | sleepy | /video/live/ |
> | 8 | Default | moktoo | /video/mythtv/ |
> | 10 | LiveTV | moktoo | /video/live/ |
> | 11 | Big Brother | moktoo | /video/bb7/ |
> | 12 | Default | mingus | /video/mythtv/ |
> | 13 | LiveTV | mingus | /video/live/ |
> I use the special group "LiveTV". These write to the same
> partition but I like to keep the files seperate so I know
> that everything in /video/mythtv/ is a recording and I can
> check /video/live/ to see if there are old files left over
> from a crash or something,
> Storage Groups know which disk it is using ever if I give
> different directory choices. Therefore, If I have a recording
> going in nordtv:/video/mythtv/ and I start a live session on a
> second card on this machine, it will choose "/archive/live/"(!).
> If /archive/mythtv/ was used instead, the live session would go
> to /video/live/. Slick, hey?
> I also kept all 29 episodes of Big Brother 7: All-Stars and
> put these in their own space. I can keep files from this series
> on either of two machines. If there were more upcoming episode
> (which there aren't), The record rule could have the SG set
> to "Big Brother" so the recorder would know that it should
> try to write to a directory for this group and help me keep
> them separate.
> -- bjm
To me it sounded like he had 2 physical discs which he partitioned 7
times between the two, and that many of the partions are 50GB XFS
partions, each configured to be a storage group. This is how I'm
interpretting what he said... but let's go with that as I'm trying to
get an understanding of the optimization of multiple tuners recording
at the same time with multiple storage groups.
For this example, lets say we have two 200GB HD and 4 tuners. Can you
give us a comparison of which of the following scenarios would be best
if all 4 tuners are recording at the same time. I'm also assuming
that these disks are only used for MythTV and not for any other OS or
1) No storage groups - 1 directory on a single partition - obviously,
this is what a lot of people see now, and is worst case from a disk
I/O performance standpoint
2) Storage groups - 1 partition on disk 1, 1 partition on disk 2. The
4 tuners will be recording, most likely, two to a partition.
3) Storage groups - 2 partitions on disk 1, 2 paritions on disk 2.
The 4 tuners will be recording, most likely, one to a partition.
Is there any benefit to having the head thrashing 2 different places
on a single disk with partitions versus without partitions? I hope I
clearly stated what I was trying to get at.
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