Routine Maintenance

[broderp]

In light of my experience last night, I was wondering what effects if any automatically scheduling activities like DEFRAG and scan disk on my hard drives will work with a PC up and running 24/7 SAGE 2.0.

Will a defrag STOP a EPG update? Will I loose any information? Will it cause my PC to lock up and crash? What if I'm recording a show at 3AM during the time a defrag has to run?


How do you guys incorporate these tasks with the usage of sage?

Thanks.

[stanger89]

I've never defragged my Sage drive, it's not neccessary, especially if you have the drive formatted with 64k clusters. In fact I don't defrag my HTPC at all. There's only a few programs on it, and nothing gets moved around much.

I just checked my SageTV drive, and it's 49% fragmented with 99% file fragmentation, but it hasn't caused on problem. Keep in mind, you're dealing with really big files here and that they aren't fraged into many peices (my average is 6.5 fragments/file).

In fact I seem to remember some cases where Defrag actually caused problems. Defrage hits the drive pretty hard, and if it's happening while a recording is occuring it can actually lead to corrupted recordings.

[Opus4]

I used to defrag (& still do for my work machine), but I've got SageTV recordings with _thousands_ of fragments and they play perfectly. The 64K cluster size is the key, like stanger89 said.

- Andy

[broderp]

OK, how do I get 64K cluster sizes, how dies it benifit over the NTFS file system?

Can I add a partision to my HD or must I use some utility to do it? (I've done this many times with win98SE PC's and a boot disk.

How will MPEG2 recorded on a 64K cluster partition play with/ interact with a different PC that is NTFS? (I will be transfering files to put on DVD, onto a different PC, and the software I use is PICKY)

[stanger89]

Originally posted by broderp
OK, how do I get 64K cluster sizes, how dies it benifit over the NTFS file system?

You use 64K cluster with NTFS, you just use the format utility and select 65536 as the alocation unit size (this will format the drive so don't do it if there's something important there).

Can I add a partision to my HD or must I use some utility to do it? (I've done this many times with win98SE PC's and a boot disk.

You can do it when you install windows, but to do it without reinstalling you need to use something like Acronis Partition Expert to resize the OS partition and create a new one after it.

How will MPEG2 recorded on a 64K cluster partition play with/ interact with a different PC that is NTFS? (I will be transfering files to put on DVD, onto a different PC, and the software I use is PICKY)

Cluster size is transparent to the user, it makes no difference either on the local PC or to any other networked PC. You're still using NTFS, just NTFS with 64K clusters instead of NTFS with the default 4K clusters.

[Opus4]

Like stanger89 said, you can use 3rd party utilites to partition/format/resize clusters & they can do it w/o destroying the existing data. (OK, you can't reformat w/o destroying data, but you can resize the partitions or clusters.) In addition to the Acronis utility he mentioned, I have never had a problem using Partition Magic for such tasks.

- Andy

[cmaffia]

I partitioned my 160GB hard drive after I had tweaked and installed my OS. Preferably partioning a drive prior to OS installation and configuration is recommended. I used Partion Magic 7.0 on my Windows XP SP1 without any problems.

[Lester Jacobs]

Originally posted by stanger89
I've never defragged my Sage drive, it's not neccessary, especially if you have the drive formatted with 64k clusters. ...

Actually, I have somewhat of a different experience. I have a 120GB drive dedicated to SageTV and formatted with 64k clusters. It's been running fine for about a year.

Recently, I noticed that Sage was taking longer and longer to change channels, sometimes up to 1 minute or even 2 minutes. During these periods, the hard drive light would come on solid. I surmised that the hard drive might be fragmented and did a check. My files were 99% fragmented. More importantly, my free space was also 99% fragmented. In fact it was so fragmented that instead of having blocks of red and white in the defragmenter analysis like it usually shows, my drive showed as a solid pink block. This was obviously simply alternating red and white lines.

I copied all of the recordings from my Sage drive to another drive, reformatted it, then copied the files back. Since then channel change performance in Sage has vastly improved. In fact it's back to the level where it was when I first installed Sage a year ago.

So while I agree that 64k clusters do help tremendously with the fragmentation issue, I believe that performance will deteriorate at some point and a defragmentation will be required.

Incidentally, my drive was so fragmented that even the defragger wouldn't touch it (assumedly it needed a certain amount of free space to work which it didn't have) so I have to use the copy off - reformat - copy back technique.

Cheers
Lester

[stanger89]

But still, I'd only recommend running defrag manually, without sage running, and only if there is something you are trying to fix (like the situation Lester mentioned).

[korki]

Hello.

Running defrag isn't possible for 64k aloc.unit in win xp sp2. What is the alternative ? Only move and copy back all stuf ?

Thank's

[stanger89]

Don't bother, I never do.

[dooferlad]

If you have unfragmented free space you can easily defrag a file by making a copy of it and deleting the original. When Sage writes a file it doesn't tell the OS what size it is going to be, so Windows won't know to start writing at the start of a huge chunk of free space. When the file is complete and you make a copy of the file, Windows will know how big the file is and will write it in as large a chunks as it can.

You probably benefit from using a partition dedicated to video because when a large file is deleted it leaved a large hunk of free space behind, which is hopefully continuous. If you only have one tuner and only Sage writing to that partition you can expect very little fragmentation. As soon as you have more than one tuner you will run into problems.

There are a couple of things that the Sage guys could do to get around the problems of disk fragmentation:

1. Read ahead more
2. Create large empty files before a recording is due to start and write into them - hopefully if you ask the OS for 3Gb of disk space it will give you a 3Gb continuous chunk (if it has one). I would guess that most recordings are CBR, so you shouldn't waste too much disk space doing this.

Clearly 1 is the best option. I would happily give up 32Mb of RAM or so to ensure my disk was never holding back playback.

[blade]

Originally Posted by stanger89

Don't bother, I never do.

Neither do I. Been running Sage for almost a year and a half and never defrag.

[gplasky]

Originally Posted by blade

Neither do I. Been running Sage for almost a year and a half and never defrag.

Same machine, same drives, same config (2 x 160 GB SATA drives in RAID 0) and 64K blocks for over 3 years and never defragged.

Gerry

[BobPhoenix]

Just under 1TB - 6 tuners - never been defraged in 1 and 1/2 years.

BobP.