Re: [PATCH 1/2] fs: Do not dispatch FITRIM through separate super_operation

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 10-11-18 04:50 PM, Markus Trippelsdorf wrote:
On 2010.11.18 at 16:45 -0500, Mark Lord wrote:
On 10-11-18 02:32 PM, Markus Trippelsdorf wrote:
On 2010.11.18 at 18:05 +0000, Jamie Lokier wrote:
Online trim may be slow, but offline would be awfully inconvenient
when an fs is big and needed for a live system, or when it's your root fs.

You can call FITRIM from a running system. Infact I run it once per week
as a cron job on my (mounted) root fs.


Ditto for wiper.sh.

But I always thought that wiper has no access to the filesystem
internals. So there is always a chance that you write to a sector that
wiper.sh is currently trimming. FITRIM should be safer in this regard.


No, wiper.sh is very safe for online TRIM.
It reserves the blocks before trimming them, so nothing else can write to them.

The danger with wiper.sh, is that WHILE it is running, it reserves most
of the free space of the filesystem.  So if there are other apps writing
tons of new data to the drive, while not freeing up old data, the system
can run low on diskspace for a moment.

wiper.sh counters that by not reserving/trimming *everything* when run online,
leaving a reasonable amount of scratch space available for other apps during the run.

This is where having a fully capable FITRIM, with multi-range TRIMs, would be useful.

Cheers
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Reiser Filesystem Development]     [Ceph FS]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite National Park]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]     [Linux Media]

  Powered by Linux